Matthieu Harlaux
email: m.harlaux@brgm.fr

Daniel J Kontak

Alan H Clark

Kalin Kouzmanov

et al.. Depositing >1 Christopher S Holm-Denoma

Stefano Gialli

Oscar Laurent

Richard Spikings

Alain Chauvet

Andrea Dini

Miroslav Kalinaj

Lluís Fontboté

A Lorenzo Bernini

Depositing >1.5 Mt of Tin Within

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Determining the lifetime of magmatic-hydrothermal systems is of great importance as it provides the temporal constraints, or geological timescales, necessary for understanding processes responsible for the formation of ore deposits. In the last years, significant advances have been done to determine the duration of magmatic-hydrothermal processes, with a specific focus on the formation of porphyry Cu (-Au-Mo) systems, based on high-precision geochronology techniques (e.g., [START_REF] Deckart | Magmatic and hydrothermal chronology of the giant Río Blanco porphyry copper deposit, central Chile: Implications of an integrated U-Pb and 40 Ar/ 39 Ar database[END_REF][START_REF] Catchpole | Timing of porphyry (Cu-Mo) and base metal (Zn-Pb-Ag-Cu) mineralisation in a magmatic-hydrothermal system-Morococha district[END_REF][START_REF] Chelle-Michou | Highresolution geochronology of the Coroccohuayco porphyry-skarn deposit, Peru: A rapid product of the Incaic Orogeny[END_REF][START_REF] Buret | From a long-lived upper-crustal magma chamber to rapid porphyry copper emplacement: Reading the geochemistry of zircon crystals at Bajo de la Alumbrera (NW Argentina)[END_REF][START_REF] Tapster | Rapid thermal rejuvenation of high-crystallinity magma linked to porphyry copper deposit formation; evidence from the Koloula Porphyry Prospect[END_REF][START_REF] Li | Cyclic magmatic-hydrothermal evolution in porphyry systems: High-precision U-Pb and Re-Os geochronology constraints on the Tibetan Qulong porphyry Cu-Mo deposit[END_REF][START_REF] Rottier | Multiple rejuvenation episodes of a silicic magma reservoir at the origin of the large diatreme-dome complex and porphyry-type mineralization events at Cerro de Pasco[END_REF] and element diffusion modeling (e.g., [START_REF] Mercer | Time scales of porphyry Cu deposit formation: Insights from titanium diffusion in quartz[END_REF][START_REF] Cernuschi | Rapid formation of porphyry copper deposits evidenced by diffusion of oxygen and titanium in quartz[END_REF]. High-precision U-Pb dating of igneous zircons has revealed periods of <1 Myr between magma crystallization and extraction of ore-forming fluids, with timespans as short as a few 10,000s yr between individual fluid pulses (e.g., [START_REF] Deckart | Magmatic and hydrothermal chronology of the giant Río Blanco porphyry copper deposit, central Chile: Implications of an integrated U-Pb and 40 Ar/ 39 Ar database[END_REF][START_REF] Von Quadt | Zircon crystallization and the lifetimes of ore-forming magmatic-hydrothermal systems[END_REF][START_REF] Chiaradia | How accurately can we date the duration of magmatic-hydrothermal events in porphyry systems? -An invited paper[END_REF][START_REF] Spencer | The distribution and timing of molybdenite mineralization at the El Teniente Cu-Mo porphyry deposit[END_REF][START_REF] Tapster | Rapid thermal rejuvenation of high-crystallinity magma linked to porphyry copper deposit formation; evidence from the Koloula Porphyry Prospect[END_REF][START_REF] Large | Copper-mineralised porphyries sample the evolution of a large-volume silicic magma reservoir from rapid assembly to solidification[END_REF]. Until recently the lifetime of granite-related Sn and/or W deposits had yet to be investigated in such detail compared to porphyry Cu (-Mo) systems. New insight has been provided for the timing and duration of Sn±W ore deposit formation via U-Pb dating of ore minerals such as cassiterite and wolframite (e.g., [START_REF] Zhang | Cassiterite U-Pb geochronology constrains magmatic-hydrothermal evolution in complex evolved granite systems: The classic Erzgebirge tin province[END_REF]Harlaux et al., 2018a;[START_REF] Moscati | U-Pb geochronology of tin deposits associated with the Cornubian Batholith of southwest England: Direct dating of cassiterite by in situ LA-ICPMS[END_REF][START_REF] Tang | LA-ICP-MS U-Pb geochronology of wolframite by combining NIST series and common lead-bearing MTM as the primary reference material: implications for metallogenesis of South China[END_REF][START_REF] Denholm | The Geochronology of Tasmanian Tin Deposits Using LA-ICP-MS U-Pb Cassiterite Dating[END_REF] element composition of cassiterite to investigate its potential as a tracer of geologic processes during Sn deposition at San Rafael.

Geological Background

The San Rafael Sn (-Cu) deposit (latitude 14°13'58" S, longitude 70°19'18" W) is located within the Cordillera de Carabaya in the Eastern Cordillera of southeast Peru (Fig. 1A). This segment belongs to the Central Andean tin belt which extends from southern Peru, through Bolivia, to northern Argentina and hosts hundreds of Sn-W±Ag-Cu deposits and occurrences located within a 1,000-km-long and 30-to 130-km-wide belt [START_REF] Kelly | Mineralogy, paragenesis and geothermometry of the tin and tungsten deposits of the eastern Andes[END_REF][START_REF] Turneaure | The Bolivian tin-silver province[END_REF][START_REF] Grant | K-Ar ages of igneous rocks and mineralization in part of the Bolivian tin belt[END_REF][START_REF] Grant | Evolution of the Porphyry Tin Deposits of Bolivia[END_REF][START_REF] Lehmann | The Bolivian tin province and regional tin distribution in the central Andes: A reassessment[END_REF]. These deposits are spatially associated with metaluminous to peraluminous granitoids and subvolcanic stocks emplaced during two major metallogenic periods: (i) the Late Triassic -Early Jurassic that is restricted to the northern part of the belt; and (ii) the late Oligocene -early Miocene which affected the entire belt [START_REF] Grant | K-Ar ages of igneous rocks and mineralization in part of the Bolivian tin belt[END_REF][START_REF] Grant | Evolution of the Porphyry Tin Deposits of Bolivia[END_REF][START_REF] Clark | Occurrence and age of tin mineralization in the Cordillera Oriental, southern Peru[END_REF][START_REF] Clark | Geologic and geochronologic constraints on the metallogenic evolution of the Andes of southeastern Peru[END_REF][START_REF] Mcbride | Magmatic and metallogenetic episodes in the northern tin belt, Cordillera Real, Bolivia[END_REF]Kontak et al., 1990a;[START_REF] Rice | Duration of magmatic, hydrothermal, and supergene activity at Cerro Rico de Potosi[END_REF]. In situ U-Pb cassiterite dating of ore deposits in the Bolivian tin belt [START_REF] Gemmrich | Trace element composition and U-Pb ages of cassiterite from the Bolivian tin belt[END_REF] confirms the earlier geochronological studies and indicates that Sn mineralization occurred at least during two major magmatic events in the Late Triassic and in the late Oligocene -early . A significant Sn-Cu resource of similar age (~23 Ma) has been recently discovered 800 km north of San Rafael in the polymetallic deposit of Ayawilca [START_REF] Benites | Geology, mineralogy, and cassiterite geochronology of the Ayawilca Zn-Pb-Ag-In-Sn-Cu deposit[END_REF].

San Rafael is currently one of the largest and highest-grade hypogene Sn deposits in the world, with total past production (1969-present) of more than 1 million metric tonnes (Mt) of Sn with an average grade of 3.7% [START_REF] Harlaux | Tourmaline as a Tracer of Late-Magmatic to Hydrothermal Fluid Evolution: The World-Class San Rafael Tin (-Copper) Deposit[END_REF]. In 2020, total resources inventory of San Rafael was 195,300 t fine Sn in measured + indicated resources and 73,600 t fine Sn in inferred resources, while total reserves were estimated at 132,000 t fine Sn [START_REF] Minsur | Annual Report[END_REF].

Ongoing exploration in the Nazareth zone, located about 3 km northeast of the San Rafael mine (Fig. 1B), reported 82,500 t fine Sn in measured + indicated resources and 82,050 t fine Sn in inferred resources [START_REF] Minsur | Annual Report[END_REF]. Therefore, a total of at least 565,450 t Sn in resources and reserves is known in the San Rafael district, accounting for a total of past production + remaining resources of >1.5 Mt Sn. The San Rafael deposit consists of a northwest-trending quartz-cassiterite-chlorite-sulfide vein system spatially associated with an uppermost Oligocene (ca. 24 Ma) peraluminous S-type, ilmenite-bearing granitic pluton exposed in a prominent topographic high (Nevado Quenamari,5,300 masl). This domal feature is underlain by prehnite-pumpellyite facies metamorphosed and deformed Ordovician metasedimentary rocks of the Sandia Formation [START_REF] Palma | The San Rafael tin-copper deposit[END_REF] which record a contact metamorphic aureole (Fig. 1B). The mineralized lodes at San Rafael were formed along fault-jogs created by sinistralnormal, strike-slip displacements [START_REF] Mlynarczyk | San Rafael, Peru: Geology and structure of the worlds richest tin lode[END_REF][START_REF] Gialli | Structural control of the world-class Sn district of San Rafael, Peru[END_REF]. This extensional structural setting is interpreted, at the district scale, to have controlled the emplacement and uplift of the granitic pluton in a pull-apart system [START_REF] Gialli | Structural control of the world-class Sn district of San Rafael, Peru[END_REF].

The surface exposure of the San Rafael intrusive complex (SRIC) is dominated by a peraluminous S-type megacrystic biotite-cordierite monzogranite characterized by pluricentimetric phenocrysts of K-feldspar (Figs. 2A and3A) with lesser comagmatic enclaves of varied granitoids and subordinate lamprophyres [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]Harlaux et al., 2021b). Other petrologic aspects of the SRIC which are relevant in the context of this study include: 1) whereas the bulk of the main intrusion constituting the SRIC is the aforementioned megacrystic facies, there are textural variants of this, namely a fine-grained granite that shows progressive gradual contacts toward the granitic cupola; 2) in the upper part of the intrusion, granophyric to graphic textures are noted; and 3) a variety of granitic phases and lamprophyres are observed deeper in the SRIC, such as comagmatic enclaves and dikes, demonstrating commingling and mixing of felsic and mafic magma batches [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]Harlaux et al., 2021b). Selected samples illustrating these features are provided in Appendix Figure A1 and the reader is referred to Harlaux et al. (2021b) for details. The SRIC has two major components, i.e., the San Rafael granite exposed in the southwestern part of the district and the Quenamari granite occurring in its northeastern part. Importantly, both bodies, which are discrete entities at surface, coalesce at depth as indicated by boreholes and underground workings (Fig. 1C). Furthermore, the SRIC is circumscribed by porphyritic ring dikes (RD on Fig. 1B), which are petrologically similar to the central granite (i.e., contain biotite ± cordierite) and exhibit quenched textures [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]. The southwestern tip of the San Rafael granite cupola is affected by greisenization at an elevation of >4,800 masl. The greisen occurs as an elongated body extending approximately 600 m in NNW-SSE direction close to the contact with the metasedimentary rocks of the Sandia Formation (Fig. 1B). This area is transitional to the megacrystic granite and consists of a quartz-muscovite greisen with minor tourmaline and dumortierite [START_REF] Gialli | Early hydrothermal alteration stages at the giant San Rafael tin deposit[END_REF]Harlaux et al., 2021b).

Analytical Methods

Petrography and automated mineralogy

Petrographic observations were carried out using transmitted-light microscopy combined with cold cathodoluminescence (CL) imaging to characterize the mineral textures. The CL images were acquired at the University of Geneva (Switzerland) using an Cathodyne ® electron cathode from NewTec Scientific, mounted on a Olympus BX41 microscope operated with an acceleration voltage of 18 kV, a gun current of 120-200 µA, and with a processing resolution of 1,600 x 1,200 pixels. Automated mineral analysis and textural imaging of the samples were carried out using a FEI QEMSCAN Quanta 650 F facility at the University of Geneva. The QEMSCAN system is equipped with two Bruker QUANTAX light-element energy-dispersive X-ray spectrometer (EDS) detectors. Analyses were conducted in field image operating mode at high vacuum [START_REF] Pirrie | Rapid quantitative mineral and phase analysis using automated scanning electron microscopy (QemSCAN): Potential applications in forensic geoscience[END_REF], accelerating voltage of 25 kV, and using a beam current of 10 nA on carbon-coated polished thin sections. In total, 221 individual fields were measured per sample, with a field size of 1,500 x 1,500 µm, and a point spacing of 5 µm. The standard 1,000 counts per point were acquired, yielding a limit of detection of approximately 2 wt.% per element for mineral classification. Measurements were performed using the iMeasure v5.3.2 software, and the iDiscover v5.3.2 software package was used for data processing. Results consist of spatially resolved and fully quantified mineralogical maps and X-ray elemental distribution maps.

40 Ar/ 39 Ar dating, Queen's University Mineral separates of K-feldspar and mica (biotite, muscovite) prepared using conventional methods (i.e., crushing and sieving, magnetic separator, heavy liquids, handpicking) and flux monitors (standard LP-6 biotite: 128.1 ± 0.3 Ma; [START_REF] Baksi | Intercalibration of 40 Ar/ 39 Ar dating standards[END_REF]127.5 ± 0.3 Ma;[START_REF] Spell | Characterization and calibration of 40 Ar/ 39 Ar dating standards[END_REF]; and internal standard SP-85 biotite: 18.9 ± 0.3 Ma; [START_REF] Quang | Response of supergene processes to episodic Cenozoic uplift, pediment erosion, and ignimbrite eruption in the porphyry copper province of southern Peru[END_REF] were wrapped in Al-foil and together loaded into a radiation canister and irradiated with fast neutrons in position 5C of the McMaster University nuclear reactor (Hamilton, Ontario, Canada) for 20 hours. The standards were evenly spaced with the unknowns to enable precise determination of the irradiation parameter J throughout the canister. Approximately 250-300 mg of sample material was loaded into degassed (1200°C) Nb crucibles and placed in a quartz tube connected to a stainless-steel extraction system and step-heated using a Lindberg furnace. Argon isotopes were measured at Queen's University (Kingston, Canada) using a bakeable, ultra-high vacuum, stainless-steel Ar extraction system operated on-line to a substantially modified, A.E.I. MS-10 mass spectrometer which was run in the static mode. Measured Ar isotope ratios were extrapolated to zero-time and corrected for neutron-induced 40 Ar from K, and 39 Ar and 36 Ar from Ca. The atmospheric 40 Ar/ 36 Ar ratio was measured regularly, and appropriate corrections were applied. Ages (i.e., plateau, correlation, and integrated) and uncertainties were calculated using IsoplotR [START_REF] Vermeesch | IsoplotR: A free and open toolbox for geochronology[END_REF] and the decay constants and isotope abundance ratios recommended by [START_REF] Steiger | Subcommission on geochronology: convention on the use of decay constants in geo-and cosmochronology[END_REF]. An additional component of uncertainty is introduced by inhomogeneity of the reference material LP-6 biotite, as reported by [START_REF] Spell | Characterization and calibration of 40 Ar/ 39 Ar dating standards[END_REF]. The full Ar isotope dataset is presented in Appendix Table A1. 40 Ar/ 39 Ar dating, University of Geneva Mineral separates of adularia were concentrated from representative splits of the crushed rocks using magnetic and heavy liquid separation techniques and finally handpicked (~99.9% purity) under a binocular microscope. Adularia concentrates were rinsed in deionized water, packed in copper foil and irradiated in the CLICIT facility of the TRIGA reactor at Oregon State University (USA) for 3.5 hours. Fish Canyon Tuff sanidine (Kuiper et al., 2008) was used to monitor neutron fluxes. Samples were degassed by step-heating with a 55W CO2-IR laser (Photon Machines Inc.) that was rastered over the samples to provide even-heating of the grains, and the extracted gas was gettered (SAES GP50 ST101 and AP10) in a stainless steel UHV line, after passing through a cold trap chilled to ~150 K. Argon isotopes were analyzed at the University of Geneva using a multi-collector GV Instruments Argus V mass spectrometer equipped with four high-gain (10 12 Ω) Faraday detectors, and a single 10 11 Ω Faraday detector ( 40 Ar), with a procedure identical to that described in Villagomez and Spikings (2013). Timezero regressions were fitted to data collected from twelve cycles. Data reduction and calculation of age plateaus were performed utilizing ArArCalc [START_REF] Koppers | ArArCALC-software for 40 Ar/ 39 Ar age calculations[END_REF] and IsoplotR [START_REF] Vermeesch | IsoplotR: A free and open toolbox for geochronology[END_REF]. Blank measurements were made after every three step analyses, and mass discrimination was determined from analyses of gettered air, which were made daily. The full Ar isotope dataset is presented in Table A2.

U-Pb dating of cassiterite, USGS Denver

U-Pb isotope analyses of cassiterite were conducted at the United States Geological Survey (USGS) Denver Science Federal Center (USA), G3 Plasma Laboratory using a Nu Instruments AttoM™ sector-field inductively coupled plasmamass spectrometer (ICP-MS) coupled to a Teledyne-Photon Machines Excite™ 193 nm ArF excimer laser system with a HelEx II 2volume ablation cell. Polished thin sections of cassiterite and standard reference materials NIST-610 and NIST-612 glass were ablated using spot mode (150 total bursts) with a repetition rate of 5 Hz, laser energy of 3-5 mJ, and an energy density of 4-5 J/cm 2 . The rate of He gas flow to the HelEx cell of the laser was ~0.5 L/min and make-up Ar gas (0.21-0.29 L/min) was added to the sample stream prior to introduction into the plasma. Nitrogen, with flow rate of 5.5-6.0 mL/min, was added to the sample stream, which allowed for significant reduction in oxide formation (monitored during the mass spectrometer tuning) to obtain ThO + /Th + (<0.5%) and improved the ionization efficiency of refractory Th [START_REF] Hu | Signal enhancement in laser ablation ICP-MS by addition of nitrogen in the central channel gas[END_REF]. With the magnet parked at a constant mass, flat tops of the isotope peaks were measured at the following masses by rapidly deflecting the ion beam: 202 Hg, 204 (Hg+Pb), 206 Pb, 207 Pb, 208 Pb, 232 Th, 235 U, and 238 U.

On-peak backgrounds for each peak were measured for 30 s prior to each 30 s analysis. A discrete dynode electron multiplier ion-counting detector was always used operating below the limit of the ion beam attenuation (<2.5×10 6 cps). Raw data were reduced off-line using the Iolite™ 2.5 program and U_Pb_Geochronology3 Data Reduction Scheme [START_REF] Paton | Iolite: Freeware for the visualisation and processing of mass spectrometric data[END_REF] to subtract on-peak background signals, correct for Pb isotope fractionation and U-Pb downhole fractionation, normalize the instrumental mass bias, and determine the concentration of U, Pb, and Th. NIST-610 glass standard was analyzed in each session to evaluate U and Th concentrations. A laser spot size of 85-110 µm was used. Pit depths of ~9-10 µm resulted in pit aspect ratios (diameter/depth) of >5 so that downhole U/Pb fractionation is minimized. An ~1.54 Ga low-Th cassiterite sample (named "SPG-IV") from a mineralized skarn in Russian Karelia with an apparently closed U-Pb system was analyzed during each analytical session (five analyses after five unknowns) as a matrix-matched reference material [START_REF] Neymark | In situ LA-ICPMS U-Pb dating of cassiterite without a known-age matrix-matched reference material: Examples from worldwide tin deposits spanning the Proterozoic to the Tertiary[END_REF]. NIST-612 (two analyses after five unknowns), the cassiterite reference material (SPG-IV), and the cassiterite unknowns are all analyzed under the same conditions during each analytical session.

Data reduction for cassiterite is complicated by the presence of variable amounts of common Pb and the absence of a well-characterized matrix-matched cassiterite reference material. To avoid these complications, [START_REF] Neymark | In situ LA-ICPMS U-Pb dating of cassiterite without a known-age matrix-matched reference material: Examples from worldwide tin deposits spanning the Proterozoic to the Tertiary[END_REF] developed a novel approach that does not require an ID-TIMS characterized reference material; this approach was adopted for this study. Using normalization to the 238 U/ 206 Pb and 207 Pb/ 206 Pb isotopic ratios of NIST-612, biased lower intercept U-Pb isotopic dates were calculated for the ~1.54 Ga SPG-IV cassiterite measured in the same analytical sessions as unknowns by constructing a Tera-Wasserburg isochron diagram. The measured long-term average 207 Pb/ 206 Pb date of more than 100 replicate LA-ICP-MS analyses of this cassiterite is 1541.2 ± 9.5 Ma (2SD), which is within uncertainty of the recently published ID-TIMS age for this sample of 1535.9 ± 5.5 Ma [START_REF] Tapster | High-precision ID-TIMS Cassiterite U-Pb systematics using a low-contamination hydrothermal decomposition: implications for LA-ICP-MS and ore deposit geochronology: Geochronology[END_REF]. The difference between the biased lower intercept U-Pb date and the obtained 207 Pb/ 206 Pb date of the cassiterite reference material SPG-IV is used to correct for the matrix effect and the instrumental bias on 238 U/ 206 Pb ratios. A more detailed discussion of the analytical and data reduction methods can be found in [START_REF] Neymark | In situ LA-ICPMS U-Pb dating of cassiterite without a known-age matrix-matched reference material: Examples from worldwide tin deposits spanning the Proterozoic to the Tertiary[END_REF]. The full U-Pb isotope dataset of cassiterite, including results on cassiterite SPG-IV, is presented in Table A3. Data were plotted using IsoplotR [START_REF] Vermeesch | IsoplotR: A free and open toolbox for geochronology[END_REF], and uncertainties in tables and text are quoted at the 2σ level.

Major and trace element analysis of cassiterite

The major element composition of cassiterite was determined by electron microprobe analyses (EMPA) using a JEOL JXA-8200 Superprobe microanalyzer equipped with five wavelengthdispersive X-ray spectrometers (WDS) at the University of Geneva. Operating conditions were as follows: acceleration voltage of 20 kV, beam current of 20 nA, and beam diameter of 5 μm.

Analytical standards, with the corresponding lines, and limits of detection used for analyses, were: SnO2 (Sn, L⍺, 150 ppm), TiO2 (Ti, K⍺, 110 ppm), MnTiO3 (Mn, K⍺, 100 ppm), Ta2O5 (Ta, L⍺, 350 ppm), Nb2O5 (Nb, L⍺, 200 ppm), Fe2O3 (Fe, K⍺, 100 ppm), W-metal (W, L⍺, 150 ppm), and In-metal (In, L⍺, 150 ppm). Chemical compositions of cassiterite are reported in weight per cent (wt.%) oxides and structural formulae, normalized to two oxygen atoms, are expressed in atoms per formula unit (apfu). Results of EMPA measurements are reported in Table A4.

Cassiterite trace element analyses were carried out at the ETH Zürich (Switzerland) by LA-ICP-MS using a RESOlution (Australian Scientific Instruments) 193 nm ArF excimer laser system attached to an Element XR (Thermo Scientific, Germany) sector-field mass spectrometer. Analyses were performed on the same polished thin sections of cassiterite prior to the U-Pb isotope analyses at the USGS. Samples were loaded in a Laurin Technic S-155 dual-volume ablation cell fluxed with carrier gas consisting of ca. 0.5 L/min He (5.0 grade) and sample gas from the ICP-MS consisting of ca. 1 L/min Ar (6.0 grade) mixed with ca. 2 mL/min N2. We used a laser repetition rate of 3 Hz, spot diameters of 43 μm, and a laser output energy of ca. 40 mJ, corresponding to an on-sample energy density of ca. 3.6 J/cm 2 . Three pre-ablation pulses were applied immediately before each analysis for surface cleaning. Signal homogenization was performed using in-house Squid tubing. The ICP-MS was tuned for maximum sensitivity on the high mass range while keeping the production of oxides low ( 248 ThO + / 232 Th + ≈ 0.10%, Ba 2+ /Ba + ≈ 3.5%). Intensities for the 45 following isotopes were acquired using time resolved-peak jumping and triple detector mode: 27 Al, 29 Si, 45 Sc, 49 Ti, 51 V, 53 Cr, 55 Mn, 57 Fe, 65 Cu, 66 Zn, 71 Ga, 74 Ge, 75 As, 89 Y, 90 Zr, 93 49 Ti, and 51 V (5 ms), 57 Fe, 117 Sn, and 186 W (11 ms), all REEs, 206 Pb, and 207 Pb (15 ms). With these settings, the total sweep time was about 760 ms. Each measurement consisted of 30 s of gas blank measurement followed by 30 s of sample ablation.

The raw intensities were processed using the Matlab-based SILLS software [START_REF] Guillong | SILLS: A MATLAB-based program for the reduction of laser ablation ICP-MS data of homogeneous materials and inclusion[END_REF]. The analyzed In intensities on mass 113 were corrected for interferences by subtracting the contribution of 113 Cd based on the measured 111 Cd intensities and using natural isotope ratios for Cd recommended by IUPAC. Individual LA-ICP-MS spectra were checked for possible presence of micro-inclusions whereas spikes unrelated to the analyzed sample were systematically eliminated. Integration windows were defined only for plateau-like signals thus avoiding parts of the sample signal contaminated by the matrix or micro-inclusions. NIST-612 glass [START_REF] Jochum | Determination of reference values for NIST SRM 610-617 glasses following ISO guidelines: Geostandards and Geoanalytical Research[END_REF] was used as a primary reference material (analyzed with a spot diameter of 43 µm) for trace element quantification using as an internal standard the wt.% Sn content determined by EMPA. Repeated analyses of USGS glass reference materials (GSD-1G and BHVO-2G; [START_REF] Guillong | Preliminary characterisation of new glass reference materials (GSA-1G, GSC-1G, GSD-1G and GSE-1G) by laser ablation-inductively coupled plasma-mass spectrometry using 193 nm, 213 nm and 266 nm wavelengths[END_REF] were processed as unknowns with laser spot diameter of 43 µm to check accuracy and reproducibility of the analyses. Results show that reproducibility ranges from 3 to 12% (2SD, increasing with decreasing concentration) for all analyzed trace elements, and that the analyses are accurate within this level of analytical uncertainty. Limits of detection (LOD) were calculated using the equation of [START_REF] Pettke | Recent developments in element concentration and isotope ratio analysis of individual fluid inclusions by laser ablation single and multiple collector ICP-MS[END_REF] and are reported together with the trace element dataset in Table A5.

Revised Paragenetic Sequence of the San Rafael Deposit

Based on new petrographic observations and building on previous work [START_REF] Palma | The San Rafael tin-copper deposit[END_REF][START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Mlynarczyk | San Rafael, Peru: Geology and structure of the worlds richest tin lode[END_REF][START_REF] Mlynarczyk | Zoned tourmaline associated with cassiterite: implications for fluid evolution and tin mineralization in the San Rafael Sn-Cu deposit, southeastern Peru[END_REF]Wagner et al., 2009;[START_REF] Corthay | The Quenamari prospect, San Rafael tin district, southern Peru: Geology, mineral assemblages, fluid inclusion microthermometry, and stable isotopes[END_REF]Prado Flores, 2015;[START_REF] Gialli | Early hydrothermal alteration stages at the giant San Rafael tin deposit[END_REF][START_REF] Harlaux | Tourmaline as a Tracer of Late-Magmatic to Hydrothermal Fluid Evolution: The World-Class San Rafael Tin (-Copper) Deposit[END_REF]Harlaux et al., , 2021bHarlaux et al., , 2021c;;[START_REF] Cazorla Martínez | Fluid evolution in the San Rafael Sn-Cu lode deposit[END_REF], we propose a revised paragenetic sequence for the San Rafael Sn (-Cu) deposit that is divided into five main stages (Fig. 4):

Pervasive alkali metasomatism (stage 0)

Granitic rocks composing the SRIC are widely affected by pervasive alkali metasomatism that occurred during cooling of the pluton and represents the earliest hydrothermal alteration recognized at San Rafael, mainly in the upper 500 m of the intrusive complex. This event consists of potassic alteration of the granitic groundmass resulting in partial replacement of igneous plagioclase and perthitic K-feldspar phenocrysts by discrete patches of hydrothermal Ba-rich K-feldspar, initially along fractures and grain boundaries [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF].

Subsequently, the granitic rocks were affected by pervasive sodic alteration which represents the dominant subsolidus alteration in the deepest parts of the SRIC [START_REF] Gialli | Early hydrothermal alteration stages at the giant San Rafael tin deposit[END_REF]. Sodic alteration resulted in hydrothermal albite which selectively replaced and formed overgrowths on magmatic K-feldspars (i.e., "pseudo-rapakivi" texture according to [START_REF] Kontak | The influences of fluid and rock compositions, and tectono-thermal processes on Al-Si distribution in alkali feldspars in granitoid rocks[END_REF].

Nevertheless, it is still unclear whether these observations reflect a temporal decoupling of Na alteration overprinting previous K alteration, or a vertical zonation of alkali metasomatism at the pluton scale. QEMSCAN mineral maps illustrating this early pervasive (K)-Na metasomatism are provided in Figure A2.

Greisenization and quartz-tourmaline veining/brecciation (stage I)

Alkali metasomatism of the granitic pluton was followed by the emplacement of pre-ore quartztourmaline veins and breccias, which cut the multiple phases of the SRIC and the metasedimentary host rocks (Fig. 2C). The emplacement of quartz-tourmaline veins was preceded by or was synchronous to the development of a quartz-muscovite greisen, which crops out in the southwestern part of the San Rafael granite (Fig. 1; Harlaux et al., 2021b) and along the contact between the megacrystic granite and the hornfelsed phyllites [START_REF] Palma | The San Rafael tin-copper deposit[END_REF].

Temporal relationships between alkali metasomatism and greisenization are unclear, but we propose that greisen formation postdated (K)-Na alteration based on the lack of hydrothermal albite overprinting the greisen and the local development of greisen alteration halos along the early quartz-tourmaline veins crosscutting the metasomatized granitic rocks. The greisen consists dominantly of a quartz-muscovite assemblage (>95% rock volume) containing sparse patches of tourmaline and dumortierite (Figs. 2B-3B and A3). Locally, holtite that replaced dumortierite was identified by optical microscopy and Raman spectroscopy (Fig. A3). Most of the major magmatic minerals (plagioclase, K-feldspar, biotite, cordierite) are altered, except for quartz and rare residual feldspars. In addition, the primary igneous texture, excepting that of the primary quartz, is destroyed. Field observations show that the intensity of greisenization varies spatially and increases progressively towards the upper part of the granitic stock, which suggests ponding of orthomagmatic fluids during cooling of the San Rafael pluton. The quartztourmaline veins, mostly subvertical and narrow (<2 cm wide), are commonly rimmed by alteration halos of variable thickness dominantly composed of hydrothermal albite (Figs. 2C and3C). Based on rock staining and QEMSCAN imaging [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]Gialli et al., 2019), this vein-restricted Na alteration is interpreted to accompany the development of the quartz-tourmaline veins as the fluids were progressively neutralized during interactions with the host granitic rocks. Lastly, arsenopyrite is found in the quartz-tourmaline veins/breccias with minor amounts of löllingite and hexagonal pyrrhotite, a mineral assemblage that is characteristic of low-sulfidation conditions [START_REF] Einaudi | Sulfidation state of fluids in active and extinct hydrothermal systems: Transitions from porphyry to epithermal environments[END_REF]. Accessory apatite and rutile are also observed in the quartz-tourmaline veins and breccias. There are several macroscopicand microscopic-scale observations that suggest that the fluids related to this tourmaline stage infiltrated large amounts of the SRIC [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Mlynarczyk | Zoned tourmaline associated with cassiterite: implications for fluid evolution and tin mineralization in the San Rafael Sn-Cu deposit, southeastern Peru[END_REF][START_REF] Harlaux | Tourmaline as a Tracer of Late-Magmatic to Hydrothermal Fluid Evolution: The World-Class San Rafael Tin (-Copper) Deposit[END_REF]: 1) presence of radial tourmaline pseudomorphs after Kfeldspar megacrysts; 2) variable development of disseminated tourmaline in the granitic groundmass throughout the SRIC; and 3) widespread occurrence of secondary fluid inclusions in magmatic quartz phenocrysts. These fluid inclusions include two-phase liquid-rich inclusions (L-V) with vapor phase <30%, two-phase vapor-rich inclusions (V) containing >80% vapor, and hypersaline multiphase inclusions (L-V-H) containing halite, sylvite, and other solids. Notably, whereas the L-V types are similar to those observed in the ore stages, the other two are only seen in the early quartz-tourmaline stage [START_REF] Palma | The San Rafael tin-copper deposit[END_REF][START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Wagner | Stable isotope constraints on ore formation at the San Rafael tin-copper deposit[END_REF][START_REF] Cazorla Martínez | Fluid evolution in the San Rafael Sn-Cu lode deposit[END_REF].

Main cassiterite ore mineralization (stage II)

The main Sn-ore assemblage is formed during this stage and consists dominantly of quartz, cassiterite, and chlorite, with minor tourmaline in veins and breccias that locally reopened preexisting quartz-tourmaline veins. Tin mineralization occurs either as botryoidal cassiterite ("wood tin"; Figs. 2D and3D) or as coarse-grained cassiterite (Figs. 2E and3E), which are both intimately intergrown with chlorite and quartz [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Mlynarczyk | San Rafael, Peru: Geology and structure of the worlds richest tin lode[END_REF][START_REF] Corthay | The Quenamari prospect, San Rafael tin district, southern Peru: Geology, mineral assemblages, fluid inclusion microthermometry, and stable isotopes[END_REF]Prado Flores, 2015). This stage is associated with an intense, pervasive development of chlorite along veins and breccia bodies and affected both the granitic stock and the metasedimentary host rocks. Hydrothermal breccias contain clasts of chloritized wall rocks cemented by quartz with both botryoidal and coarse-grained cassiterite. The complicated textures of the Sn-rich breccias indicate that this stage was not a single hydrothermal event, but instead consisted of episodic sealing and reopening producing characteristic textures of alternating cassiterite, chlorite, and quartz layers. Very minor wolframite and scheelite have been reported in some mineralized lodes [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Mlynarczyk | San Rafael, Peru: Geology and structure of the worlds richest tin lode[END_REF]. Locally, the terminal end of this stage overlaps with the stage III base-metal deposition and is best represented by the presence of alternating layers of wood tin and sphalerite.

Polymetallic sulfide and cassiterite mineralization (stage III)

During stage III, a polymetallic sulfide-dominant assemblage with abundant quartz and chlorite was deposited (Figs. 2F-3F). It occurs as quartz-chlorite-sulfide veins and breccias and as a late infill that cuts and reopened pre-existing vein generations. Sulfides include chalcopyrite, pyrite, galena, and sphalerite intergrown with lesser cassiterite and minor pyrrhotite, arsenopyrite, stannite, marcasite, native bismuth, acanthite, and various accessory sulfosalts (e.g., matildite, aleksite, kobellite, fahlore; [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Corthay | The Quenamari prospect, San Rafael tin district, southern Peru: Geology, mineral assemblages, fluid inclusion microthermometry, and stable isotopes[END_REF]Prado Flores, 2015).

Additional minerals of this stage include adularia (low-sanidine structure), fluorite, siderite, and ankerite. Stage III cassiterite was initially reported to occur as predominantly fine-grained acicular ("needle tin") in direct association with quartz, chlorite, chalcopyrite, and pyrite assemblages (Kontak and Clark, 2022;Fig. 3F). New observations in the deepest parts of the San Rafael deposit show that coarsely crystalline cassiterite was also deposited together with the full range of base metal sulfides and that, moreover, cassiterite deposition persisted locally after sulfide formation. Thus, cassiterite, either as coarse-grained or acicular in texture, was deposited during stage III, contrasting significantly with botryoidal cassiterite that is only restricted to the sulfide-absent stage II. Deposition of adularia and Fe-carbonates (siderite, ankerite) locally postdated that of base metal sulfides and cassiterite.

Quartz-carbonate veining (stage IV)

Late quartz-carbonate (mainly calcite and siderite) veins, with variable amounts of fluorite, adularia, chlorite, and Sb-Fe-Ni sulfides and sulfosalts (stibnite, gudmundite, and mackinawite), cut all previous veins and breccias and locally directly overprints the stage III quartz-sulfide assemblage (Figs. 2F and3F), indicating a continuous depositional sequence [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Corthay | The Quenamari prospect, San Rafael tin district, southern Peru: Geology, mineral assemblages, fluid inclusion microthermometry, and stable isotopes[END_REF]Prado Flores, 2015). Late rhodonite-johannsenite veins and breccias locally cut early quartz-base metal sulfide veins in the Quenamari area [START_REF] Corthay | The Quenamari prospect, San Rafael tin district, southern Peru: Geology, mineral assemblages, fluid inclusion microthermometry, and stable isotopes[END_REF], and they are thought to represent a later high-temperature hydrothermal event.

Interestingly, the Quenamari Mn-rich occurrence is close to the now inactive, Minastira Mn deposit, which is situated adjacent to a small plug of cordierite-biotite megacrystic monzogranite [START_REF] Clark | Geologic and geochronologic constraints on the metallogenic evolution of the Andes of southeastern Peru[END_REF].

Sample Description and Characterization

We have selected both magmatic (biotite, K-feldspar) and hydrothermal (muscovite, adularia, cassiterite) minerals to ascertain the lifetime of the ore-forming magmatic-hydrothermal system at San Rafael. Sample description, location, and ages are summarized in Table 1 and macroscopic (i.e., slab pictures) and microscopic (i.e., thin section scans) images of most of the dated samples in this study are provided in Figures A4 to A7.

Magmatic biotite and K-feldspar phenocrysts

Eight biotite phenocrystic separates were prepared from the cordierite-bearing K-feldspar megacrystic granite of the SRIC, including five samples from San Rafael (COCA-150, COCA-151, COCA-166A, COCA-408, COCA-1800) and three samples from Quenamari . Images showing the various nature of dated biotite samples are provided in Figures A4-A5 as thin section scans and higher magnification images. Notably the finer-grained, but also quartz-K-feldspar-cordierite-phyric, dike samples rarely had sufficient and/or fresh biotite suitable for 40 Ar/ 39 Ar dating. The single biotite sample (COCA-249) from a porphyritic ring dike, west of the San Rafael granite [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF], that was nonetheless processed for 40 Ar/ 39 Ar dating returned an irregular age spectrum, with no plateau that is suitable for age interpretation; for this reason, the data are not reported here. The other biotite separates used for dating, which come from weakly to moderately altered granites (see Table 1 and Fig. A5), are of millimetric size and their chemical composition, as determined from EMPA, is reported in [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]. Samples COCA-194 and COCA-1800 are the least altered of those dated. Whereas the former is from the main lode of the Quenamari granite, the latter was taken in the 4,200 masl adit that crosscuts the same granite. The location of this sample, approximately in the upper part of the main stock, is about 15 m E-NE of the projected downward extension of the Jorge vein. It appeared free of hydrothermal alteration and the cordierite was about 80% translucent, with only marginal pinitization.

Four samples of magmatic, megacrystic K-feldspar were used for 40 Ar/ 39 Ar geochronology (Table 1). Two samples (COCA-165B and COCA-408A) are from the least altered San Rafael cordierite-biotite megacrystic granite whereas the two other samples are from K-feldspar porphyritic ring dikes east of the Quenamari granite at an elevation of ca. 4,800-4,845 masl (see Kontak and Clark, 2002 for locations). Bulk analysis (reported as mol.% Or) of these samples yielded: COCA-165B = Or88, COCA-408A = Or76, COCA-190 = Or93, COCA-198 = Or85 [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]. Importantly, earlier detailed crystallographic and geochemical studies of the megacrystic K-feldspar phase, from both the main intrusive and ring dikes of the SRIC, were undertaken to investigate the cooling history of the magmatic phases in addition to the influence of overprinting hydrothermal activity (i.e., metasomatism) on these rocks [START_REF] Kontak | The influences of fluid and rock compositions, and tectono-thermal processes on Al-Si distribution in alkali feldspars in granitoid rocks[END_REF][START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]. We summarize below and in Figure 5 the results of the aforementioned crystallographic work, in addition to further results from [START_REF] Kontak | The magmatic and metallogenetic evolution of a craton-orogen interface: The Cordillera de Carabaya[END_REF], along with relevant petrographic observations in Figure A6. This information is relevant in the context of this study to interpret the 40 Ar/ 39 Ar age spectra for the K-feldspar separates.

X-ray diffraction (XRD) provides insight into Al-Si ordering/disorder relationships in alkali feldspars, their chemical composition, and indirectly the nature of fluids in plutons; thus, feldspars have long been a subject of study (e.g., [START_REF] Wright | X-ray and optical study of alkali feldspar-II. An X-ray method for determining the composition and structural state from measurement of 2θ values for three reflections[END_REF][START_REF] Parsons | Feldspars and fluids in cooling plutons[END_REF]. The following points are noted for studied samples from the SRIC: 1) overall K-feldspar from the Quenamari dike rocks retain a less ordered structure (i.e., intermediate between sanidine and orthoclase) than those hosted in the coarse-grained granites in both settings that are dominated by orthoclase. For comparison, data for K-feldspar megacrysts from a similar, in age (ca. 25 Ma) and composition, felsic dike at nearby Antauta (ca. 12 km south; [START_REF] Kontak | Geochronological data for Tertiary granites of the southeast Peru segment of the central Andean tin belt[END_REF] is also shown in Figure 5. As noted in the latter figure, some of the K-feldspar from dikes at Quenamari retain a highly disordered structure; 2) overall the K-feldspars are unmixed and retain primary magmatic compositions of about Or75Ab25, as inferred from their position in the XRD plot, which is further confirmed from the very minor 201 albite reflects in the XRD patterns, bulk analyses of mineral separates, EMPA analyses [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF], and petrography (see below); and 3) where metasomatism has occurred, the chemistry of the K-feldspar has changed to near end-member K-feldspar (i.e., Or100). This process was heterogeneous, in some cases affecting entire rocks whereas in others only parts of crystals, which again has been confirmed through both bulk and in situ analyses [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]. Although not shown in Figure 5, the development of albite commensurate with sodic metasomatism was also documented by the previous XRD and chemical studies, the latter showing that the primary plagioclase of An20-40 was converted to An0 during its subsolidus transformation. These features revealed through megacrysts were dominated by cryptoperthite and film perthite in least altered rocks (Figs. A1 andA6). However, these latter areas are either replaced by or traversed by discordant vein-like networks characterized by flame and blebby perthite and turbidity owing to the abundance of fluid inclusions, thus representing evidence of where coupled dissolution-reprecipitation processes have locally reconstituted the feldspar (e.g., [START_REF] Putnis | Mineral replacement reactions: from macroscopic observations to microscopic mechanisms[END_REF][START_REF] Putnis | Mineral replacement reactions[END_REF]Plümer and Putnis, 2009). Also significant is the local development of adularia-like veinlets with up to 6 wt.% BaO that cut areas of pitted orthoclase (Fig. A6; see [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF] for details).

Hydrothermal muscovite and adularia

Three samples of coarse-grained muscovite were collected from greisenized areas to constrain the timing of the early hydrothermal alteration of the SRIC concomitant with the formation of pre-ore quartz-tourmaline veins and breccias (stage I). Sample COCA-247 was collected from a quartz-muscovite-dumortierite-tourmaline greisen bordering a quartz-tourmaline vein in the megacrystic granite at San Rafael at an elevation of ca. 4,970 masl (see descriptions in [START_REF] Kontak | The magmatic and metallogenetic evolution of a craton-orogen interface: The Cordillera de Carabaya[END_REF][START_REF] Kontak | Geochronological data for Tertiary granites of the southeast Peru segment of the central Andean tin belt[END_REF] and Fig. A3). Sample SARL-406 was collected from a muscoviterich alteration zone affecting the megacrystic granite, interpreted to be related to a greisen-like alteration, and contiguous with the San Rafael lode on the level 4,770 masl [START_REF] Palma | The San Rafael tin-copper deposit[END_REF].

Sample SARL-486 originates from a muscovite-rich alteration zone in the hornfelsed phyllites in the immediate vicinity of the contact with the megacrystic granite along the road leading to the level 4,820 masl (see Palma, 1981 for descriptions). In this location, the metasedimentary rocks are cut by a steeply dipping hydrothermal breccia containing angular to rounded clasts of quartzitic rocks and coarse-grained granite within a fine-grained muscovite-rich matrix, interpreted as an exogreisen overlying the apex of the granitic intrusion. The three aforementioned samples are thought to be representative of the greisenization event following the crystallization of the granitic pluton and contemporaneous with the emplacement of stage I quartz-tourmaline veins.

Three samples of adularia were selected to date the hydrothermal stages III and IV.

Sample SARL-434 was collected at the northwestern end of the 820 adit on the Jorge lode in the level 4,820 masl of the San Rafael mine [START_REF] Palma | The San Rafael tin-copper deposit[END_REF]. This sample consists of a massive milky-white adularia intergrown with quartz and associated with a stage III base-metal sulfide assemblage composed of chalcopyrite, sphalerite, galena, and chlorite. Two additional adularia samples (SRG-43 and SR-16-KK-02; Fig. A6) were collected from stage IV quartz-adularia±fluorite veins hosted in the Sandia metasedimentary rocks in the metamorphic contact aureole of the SRIC. Sample SRG-43 was collected from the Alejandrina vein crosscutting metasedimentary rocks in the Quenamari area east of the contact with the megacrystic granite at ca. 4,920 masl. The sample has millimetric milky-white adularia intergrown with a quartzfluorite assemblage coring a re-opened chlorite-chalcopyrite vein from stage III. Sample SR-16-KK-02 is from the Estancococha area located east of the San Rafael granite at an elevation of ca. 4,720 masl. This sample is composed of millimeter-thick quartz-adularia veinlets crosscutting andalusite-bearing metasedimentary rocks. The adularia forms an aggregate of milky-white, millimeter-sized grains intergrown with quartz. Field relationships and the absence of chlorite and sulfides suggest that adularia crystallized during a later, essentially postsulfide, hydrothermal stage.

Hydrothermal cassiterite

We selected four samples of cassiterite representative of the main ore stage II that were collected in different underground levels of the San Rafael mine. Photographs of the cassiterite samples at macroscopic and microscopic scales are provided in Figure A7. Sample SRG-62-1, from the San Rafael lode in the level 4,310 masl, consists of botryoidal cassiterite ("wood tin") intergrown with chlorite and quartz that is cut by quartz-pyrite±chalcopyrite veins of stage III.

In transmitted light, cassiterite is dark brown to yellow and forms laminated bands ca. 100 to 500 µm thick. Sample SR-16-KK-14 is from a dilational jog in a historical bonanza ore body in the San Rafael lode (ca. 4,400 masl) and consists of massive wood tin, chlorite, and quartz coating breccia clasts, hence representing classical San Rafael ore (e.g., [START_REF] Mlynarczyk | San Rafael, Peru: Geology and structure of the worlds richest tin lode[END_REF]. This cassiterite is also banded and forms 100-300 µm-thick laminations of light to dark brown color in transmitted light. Sample COCA-80-1 comes from the historical San Rafael lode in the upper part of the mine (4,533 masl) and corresponds to wood tin intergrown with chlorite and quartz in typical breccia from the high-grade Sn ore zone. It is in many respects similar to sample SR-16-KK-14 described above. Sample SRG-95, from the Kimberly vein on the level 3,950 masl near the San Rafael vein, corresponds to coarse-grained cassiterite in quartz-chlorite

veins with an open-space texture. The cassiterite grains range in size from <100 µm to a few millimeters and show primary growth zoning in transmitted light with light yellow to brown colors.

Results

Biotite 40 Ar/ 39 Ar geochronology

The results of 40 Ar/ 39 Ar dating for magmatic biotite from the megacrystic biotite-cordierite granite of the SRIC are reported in Table A1 with the age spectra shown in Figures 6 and7.

Two groups of biotite samples are distinguished based on their Ar release spectra. The first group (Fig. 6) includes samples COCA-166A, COCA-194, COCA-244 and COCA-1800, which are all characterized by at least five consecutive steps accounting for >50% of the 39 Ar released with no slope, and have Mean Square Weighted Deviation (MSWD) values ≈ 1, thus representing plateaus as defined by [START_REF] Schaen | Interpreting and reporting 40 Ar/ 39 Ar geochronologic data[END_REF]. Sample COCA-166A (~6.5 wt.% K) yields a plateau date of 24.29 ± 0.26 Ma (2σ) for 78% of the released 39 Ar, which is consistent with the inverse isochron date of 24.32 ± 0.30 Ma (2σ; MSWD = 1.9; Fig. 6A). Sample COCA-194 (~7.0 wt.% K) is characterized by a plateau date of 24.35 ± 0.28 Ma (2σ), which includes 99% of the released 39 Ar and overlaps the inverse isochron date of 24.32 ± 0.30 Ma (2σ; MSWD = 1.7; Fig. 6B). Sample COCA-244 (~6.8 wt.% K) gives a plateau date of 24.52 ± 0.28 Ma (2σ) including 99% of the released 39 Ar and yields an inverse isochron date of 24.46 ± 0.30 Ma (2σ; MSWD = 0.7; Fig. 6C). Sample COCA-1800 (~7.3 wt.% K) yields a plateau date of 24.10 ± 0.26 Ma (2σ), including 99% of the released 39 Ar, which is consistent with the inverse isochron date of 24.04 ± 0.28 Ma (2σ; MSWD = 0.8; Fig. 6D).

The second group of biotite samples (Fig. 7), which includes COCA-150, COCA-151, COCA-197 and COCA-408, is characterized by slight discordance and minor hump-shaped or staircase patterns with MSWD values >> 1. Sample COCA-150 (~6.5 wt.% K) shows a staircase upward pattern with younger apparent dates calculated for the initial heating steps; it yielded an inverse isochron date of 24.90 ± 0.30 Ma (2σ; MSWD = 42; Fig. 7A). Sample COCA-151 (~6.6 wt.% K) shows a staircase downward pattern with high-temperature heating steps trending towards younger apparent dates; it yielded an inverse isochron date of 24.50 ± 0.30 Ma (2σ; MSWD = 8.2; Fig. 7B). Sample COCA-197 (~6.8 wt.% K) shows a slight humpshaped spectrum with one high-temperature step giving an older apparent date; it yielded an inverse isochron date of 24.70 ± 0.30 Ma (2σ; MSWD = 22; Fig. 7C). Sample COCA-408 (~7.1 wt.% K) is characterized by a staircase downward pattern with high-temperature heating steps trending towards younger apparent dates; it yielded an inverse isochron date of 24.80 ± 0.40 Ma (2σ; MSWD = 9.0; Fig. 7D).

K-feldspar 40 Ar/ 39 Ar geochronology

The results of 40 Ar/ 39 Ar dating of magmatic K-feldspar from the megacrystic granite are reported in Table A1 and

Muscovite and adularia 40 Ar/ 39 Ar geochronology

The 40 Ar/ 39 Ar dating of the hydrothermal stages I to IV is based on three muscovite and three adularia samples. The relevant data are reported in Tables A1 andA2 Coarse-grained muscovite sample COCA-247 (~6.8 wt.% K) from a stage I greisen bordering a quartz-tourmaline vein yielded a plateau date of 24.18 ± 0.24 Ma (2σ) representing 99% of the released 39 Ar, which overlaps the inverse isochron date of 24.21 ± 0.28 Ma (2σ; MSWD = 1.8; Fig. 9A). In comparison, muscovite sample SARL-406 (~7.5 wt.% K), which comes from a greisen-bordered mineralized vein, yielded a plateau date of 24.36 ± 0.24 Ma (2σ) for about 82% of the released 39 Ar and overlaps the inverse isochron date of 24.55 ± 0.50 Ma (2σ; MSWD = 1.2; Fig. 9B). Sample SARL-486 (~6.9 wt.% K), collected from an exogreisen muscovite-rich zone in the quartzitic metasedimentary host rocks, yielded a plateau date of 24.19 ± 0.24 Ma (2σ) for about 90% of the released 39 Ar and an inverse isochron date of 24.20 ± 0.50 Ma (2σ; MSWD = 4.5; Fig. 9C).

Adularia sample SARL-434 (~11.5 wt.% K), which is associated with the polymetallic stage III, yielded a plateau date of 22.29 ± 0.24 Ma (2σ) for 94% of the released 39 Ar and is consistent with the inverse isochron date of 22.32 ± 0.40 Ma (2σ; MSWD = 1.9; Fig. 10A). The adularia sample SRG-43 (~14.5 wt.% K), which comes from the post-ore stage IV, yielded a plateau date of 22.72 ± 0.11 Ma (2σ) for about 96% of the released 39 Ar and overlaps the inverse isochron date of 22.83 ± 0.28 Ma (2σ; MSWD = 1.4; Fig. 10B). Lastly, adularia sample SR-16-KK-02 (~15.1 wt.% K), which is also from the post-ore stage IV, yielded a plateau date of 22.43 ± 0.16 Ma (2σ) for 99% of released 39 Ar and overlaps with the inverse isochron date of 22.33 ± 0.21 Ma (2σ; MSWD = 2.1; Fig. 10C).

Cassiterite U-Pb geochronology

U-Pb isotopic analyses of cassiterite are presented in Table A3 and illustrated on Tera-Wasserburg (T-W) plots in Figure 11. In general, cassiterite has U concentrations between 2 and 70 ppm and lower Th concentrations of <0.01 to 2 ppm. All analyses defined linear trends in T-W diagrams, allowing calculation of lower intercept dates, as reported below. Botryoidal cassiterite sample SRG-62-1 (n = 80 spot analyses) yielded a date of 24.10 ± 0.37 Ma (2σ; MSWD = 3.4) and a Y-axis intercept for initial 207 Pb/ 206 Pb of 0.866 ± 0.022 (Fig. 11A).

Botryoidal cassiterite sample SR-16-KK-14 (n = 80) yielded a date of 23.88 ± 0.30 Ma (2σ; MSWD = 2.1) and a Y-axis intercept for initial 207 Pb/ 206 Pb of 0.843 ± 0.017 (Fig. 11B).

Botryoidal cassiterite sample COCA-80-1 (n = 75) yielded a date of 23.47 ± 0.53 Ma (2σ; MSWD = 1.3) and a Y-axis intercept for initial 207 Pb/ 206 Pb of 0.832 ± 0.012 (Fig. 11C). Notably, the U content of this sample (avg. U = 47 ± 9 ppm) is the highest compared to the other cassiterite samples (avg. U = 19 ± 8 ppm). Coarse-grained cassiterite sample SRG-95 (n = 80) yielded a date of 23.78 ± 0.22 Ma (2σ; MSWD = 2.7) and a Y-axis intercept for initial 207 Pb/ 206 Pb of 0.835 ± 0.016 (Fig. 11D). In summary, the four cassiterite samples analyzed yielded dates that range from 23.47 to 24.10 Ma, which overlap within their associated uncertainties.

Major and trace element composition of cassiterite

Cassiterite from San Rafael shows a restricted range in compositions with SnO2 contents between 93.7 and 100 wt.%. Of the other major elements measured, only FeO (0.2-3.9 wt.%), WO3 (up to 1.5 wt.%), and TiO2 (up to 0.6 wt.%) are present above the detection limits of the EMPA (Table A4). Minor elements detected by EMPA include Ta2O5 (up to 0.09 wt.%), In2O3 (up to 0.06 wt.%), Nb2O5 (up to 0.05 wt.%), and MnO (up to 0.02 wt.%; Table A4). Botryoidal cassiterite (samples SR-16-KK-14 and SRG-62-1) is characterized by higher FeO (0.2-3.9 wt.%, avg. = 2.3 wt.%) and lower WO3 (<0.01-0.26 wt.%, avg = 0.08 wt.%) and TiO2 (<0.01-0.20 wt.%, avg. = 0.01 wt.%) compared to coarse-grained cassiterite (sample SRG-95) which conversely has lower FeO (0.2-2.1 wt.%, avg. = 0.9 wt.%) and higher WO3 (<0.01-1.5 wt.%, avg. = 0.2 wt.%) and TiO2 (<0.01-0.56 wt.%, avg. = 0.11 wt.%).

The cassiterite trace element data are reported in Table A5 and illustrated in Figures 12 to 15. Cassiterite generally shows the following features: 1) very low to low contents (<0.1-10 ppm) of Sc, V, Cr, Mn, Cu, Zn, Ga, Ge, As, Y, Zr, Nb, Mo, Ag, Cd, Hf, Ta, Pb, Th, U, and all REEs; 2) intermediate contents (10s to 100 ppm) of Al and In; and 3) high to very high contents (100s to >1,000 ppm) of Ti, Fe, and W. Botryoidal and coarse-grained cassiterites have overlapping concentrations for most of the trace elements, however they have contrasting regression lines of element correlations, as seen in binary diagrams (Fig. 12). The concentrations of high field strength elements (HFSE) are low, including Zr (0.06-13.8 ppm; avg. = 1.2 ppm), Hf (<0.01-0.91 ppm; avg. = 0.03 ppm), Nb (0.03-137 ppm; avg. = 14.2 ppm), and Ta (<0.01-5.7 ppm; avg. = 0.22 ppm), with highly variable Zr/Hf (4-41; avg. = 18) and Nb/Ta (7-3,474; avg. = 299) ratios. The critical metal contents are also low for Ga (1.1-29.5 ppm; avg. = 17.4 ppm), Ge (0.15-3.1 ppm; avg. = 1.8 ppm), and In (1.3-49.6 ppm; avg. = 29.8 ppm), but are elevated for W (34-10,290 ppm; avg. = 1277 ppm). In multi-element diagram normalized to upper continental crust (UCC), cassiterite shows relative enrichment in In and W, and partly in Nb and Ta, between 1 and 1,000 times higher than the UCC values, and relative depletion in Sc, V, Ti, Mn, Fe, Y, Zr, Hf, and partly Nb and Ta, between 1 and 1,000 times lower than the UCC values (Fig. 13A). The total REE contents of cassiterite are uniformly low (1.3-9.3 ppm; avg. = 2.7 ppm) and show rather parallel patterns with irregular tetrad distribution in chondrite-normalized diagrams (Fig. 13B), marked by negative Ce and Eu anomalies ((Ce/Ce*)N = 0.21-0.77, (Eu/Eu*)N = 0.14-0.81), and variable ratios of (La/Yb)N (0.50-4.14), (La/Sm)N (0.82-1.31), and (Gd/Yb)N (0.69-6.54). The calculated tetrad T1 (La to Nd) and T3 (Gd to Ho) factors are >0.2 with T1 and T3 values consistently <0.8, implying a significant concave tetrad effect [START_REF] Monecke | Tetrad effect in rare earth element distribution patterns: a method of quantification with application to rock and mineral samples from granite-related rare metal deposits[END_REF].

Geochemical profiles performed across the growth banding in cassiterite, as seen in transmitted light photomicrographs and matched by CL images, show variation of several trace elements along growth direction (Figs. 14 and15). Concentrations of Fe, W and Ti vary across such growth zones between 1,000 and 10,000 ppm, 50 and 10,000 ppm, and 10 and 1,000 ppm, respectively, and correlate with the color banding and CL contrasts. We further note that the optically brownish bands show blue-greenish luminescence and have higher contents of W and Nb and lower contents of Ga and In, whereas the yellow-orange bands have a dark luminescence and correlate negatively in their trace element contents.

Discussion

Chronology of magmatic crystallization and cooling of the SRIC

A summary of all geochronological data for the San Rafael Sn (-Cu) deposit is presented in Figure 16. The 40 Ar/ 39 Ar plateau dates for magmatic biotite phenocrysts from the cordieritebearing megacrystic granite overlap within uncertainty from 24.10 ± 0.26 Ma to 24.52 ± 0.28 Ma (2σ; Fig. 6). Biotite from the least altered granite sample COCA-1800 shows the highest K content (ca. 7.3 wt.%) among all the biotite separates and thus yielded what is considered the least disturbed of these 40 Ar/ 39 Ar plateau dates at 24.10 ± 0.26 Ma (Fig. 6D). This date is interpreted as recording the time when biotite cooled below its Ar closure temperature of ca. 300°C [START_REF] Harrison | Diffusion of 40 Ar in biotite: temperature, pressure and compositional effects[END_REF][START_REF] Grove | 40 Ar* diffusion in Fe-rich biotite[END_REF]. This age overlaps with the LA-ICP-MS U-Pb zircon date of 24.02 ± 0.25 Ma (Harlaux et al., 2021b) determined on a sample of cordierite-biotite megacrystic granite taken from the currently deepest accessible part of the SRIC (level 3,610 masl) and interpreted as the crystallization age of the upper part of the pluton. This sample yielded an average crystallization temperature of ca. 730 ± 50°C based on Ti-inzircon thermometry (Harlaux et al., 2021b). This age is also in close agreement with the isotope dilutionthermal ionization mass spectrometry (ID-TIMS) 206 Pb/ 238 U concordant dates for zircon and monazite fractions of 24.70 ± 0.20 Ma and 24.60 ± 0.20 Ma (2σ), respectively, obtained for the cordierite-biotite megacrystic granite (sample COCA-408; level 4,533 masl) in the upper part of the SRIC [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]Table A6; Fig. A8).

The slight age discrepancy between the ID-TIMS and LA-ICP-MS zircon ages has been interpreted by Harlaux et al. (2021b) to reflect the possible contribution of older, inherited zircon and monazite cores, accidentally analyzed by the bulk ID-TIMS measurements. This interpretation is likely because ID-TIMS analysis of large monazite grains from the San Rafael megacrystic granite showed evidence of inheritance with 206 Pb/ 238 U date as old as 34.30 ± 0.20 Ma (Table A6; Fig. A8). Alternatively, it is also possible that the dated zircon samples, spatially separated by about 1 km vertically, correspond to two distinct batches of granitic magmas which were injected sequentially during the building of the SRIC. That both the U-Pb zircon and 40 Ar/ 39 Ar biotite ages overlap indicates that the upper part of the SRIC cooled rapidly, suggesting an upper crustal emplacement level of the granitic pluton.

The biotite samples showing slightly disturbed 40 Ar/ 39 Ar spectra, with apparent dates between 24.50 ± 0.30 Ma and 24.90 ± 0.30 Ma (2σ; Fig. 7) and with associated elevated MSWD values >> 1, are interpreted to reflect 37 Ar and/or 39 Ar recoil loss and partly radiogenic 40 Ar loss [START_REF] Kelley | Excess argon in K-Ar and Ar-Ar geochronology[END_REF][START_REF] Schaen | Interpreting and reporting 40 Ar/ 39 Ar geochronologic data[END_REF], possibly related to the various degrees of chloritization [START_REF] Roberts | Obtaining geologically meaningful 40 Ar-39 Ar ages from altered biotite[END_REF][START_REF] Vincenzo | The effect of chlorite interlayering on 40 Ar-39 Ar biotite dating: an 40 Ar-39 Ar laser-probe and TEM investigations of variably chloritised biotites[END_REF] observed in these samples (Fig. A5). These samples have up to 0.8 wt.% lower K content compared to sample COCA-1800. This interpretation is supported by previous conventional K/Ar dating of biotite from both the San Rafael and Quenamari granites and regional equivalents that also yielded older dates between 24.90 ± 0.50 Ma and 27.1 ± 1.0 Ma (2σ; [START_REF] Clark | Occurrence and age of tin mineralization in the Cordillera Oriental, southern Peru[END_REF][START_REF] Kontak | Petrogenesis of a Neogene shoshonite suite, Cerro Moromoroni[END_REF][START_REF] Kontak | Geochronological data for Tertiary granites of the southeast Peru segment of the central Andean tin belt[END_REF].

Two further aspects of the biotite 40 Ar/ 39 Ar data are explored, albeit noting the possible influence in regard to possible excess Ar in samples affected by alteration. Firstly, the average biotite ages for the megacrystic granites at San Rafael (n = 5) and Quenamari (n = 3) are 24.30 ± 0.50 Ma (2σ) and 24.40 ± 0.30 Ma (2σ), respectively. The fact that these data overlap within uncertainty the 40 Ar/ 39 Ar age of the San Rafael COCA-1800 biotite sample and also the ID-TIMS U-Pb zircon data suggests that, overall, the effect of alteration on the Ar systematics in biotite was negligible. Furthermore, the fact that the average dates of the two intrusive centers are the same within uncertainty is consistent with both geological and petrological constraints [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]Harlaux et al., 2021b). Secondly, the accuracy of the biotite 40 Ar/ 39 Ar ages can be directly assessed by comparison with the results for the three biotite samples previously dated using the Rb/Sr method [START_REF] Kontak | Geochronological data for Tertiary granites of the southeast Peru segment of the central Andean tin belt[END_REF]. These ages, recalculated using the newly defined decay constant of λ 87 Rb = 1.397 x 10 -11 a -1 [START_REF] Villa | IUPAC-IUGS recommendation on the half-life of 87 Rb[END_REF] and using a value of 87 Sr/ 86 Sr(i) = 0.718 [START_REF] Kontak | Geochronological data for Tertiary granites of the southeast Peru segment of the central Andean tin belt[END_REF], are the following (inverse isochron ages in parentheses): COCA-151 = 23.70 Ma (24.50 Ma), . The associated uncertainties for the model Rb/Sr ages are estimated at ± 0.50 Ma. Thus, for these three biotite samples, there is a good agreement between the 40 Ar/ 39 Ar and Rb/Sr chronometers, but we do note that the 40 Ar/ 39 Ar dates are consistently older by between 0.30 and 0.70 Ma which is, as noted, attributed to the effect of chlorite alteration and related recoil.

The K-feldspar phenocrysts from the main cordierite-biotite megacrystic granite all show U-shaped argon release spectra typical of excess 40 Ar, which likely records a fluid-rich open-system [START_REF] Kelley | Excess argon in K-Ar and Ar-Ar geochronology[END_REF] and has been reported to be present as fluid inclusions in K-feldspar by previous studies (e.g., [START_REF] Burgess | 40 Ar/ 39 Ar analysis of perthite microtextures and fluid inclusions in alkali feldspars from the Klokken syenite, South Greenland[END_REF]. This interpretation is consistent with the presence of variable amounts of perthite (i.e., film, flame, and bleb), secondary fluid inclusions, and micro-pores in the K-feldspars in most samples studied from the SRIC, in addition to the local development of late-stage adularia veinlets in K-feldspar phenocrysts, which all indicate variable degrees of interaction with hydrothermal fluids [START_REF] Kontak | The influences of fluid and rock compositions, and tectono-thermal processes on Al-Si distribution in alkali feldspars in granitoid rocks[END_REF][START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]; Fig. A6). For three of the four samples analyzed, the 40 Ar/ 39 Ar apparent dates calculated for the high-temperature steps for these spectra are centered around 24.20 Ma (Fig. 8), which is similar to the 40 Ar/ 39 Ar cooling dates of magmatic biotite and overlapping with that of sample COCA-1800. In contrast, the 40 Ar/ 39 Ar apparent dates calculated for the low-temperature steps are slightly variable, ranging between 22.50 ± 0.40 Ma and 23.70 ± 0.40 Ma (2σ;Fig. 8). These two domains in K-feldspar are interpreted below in regard to San Rafael samples COCA-165B, and follow on earlier studies of K-feldspar in the SRIC referred to previously.

The fact that the development of different structural, textural, and compositional domains in K-feldspar is relevant to K/Ar, and by extension to 40 Ar/ 39 Ar dating, has long been known (e.g., [START_REF] Dalrymple | Potassium-argon dating: Principles, techniques and applications to geochronology[END_REF]. This relationship has thus provided the means to model age spectra obtained from K-feldspar as relating to variable Ar diffusion and thus assesses the thermal evolution of studied samples. This approach has not however been without controversy, as discussed for example by [START_REF] Parsons | 40 Ar/ 39 Ar thermochronology using alkali feldspars: real thermal history or mathematical mirage of microtexture?[END_REF] and [START_REF] Harrison | In situ 40 K-40 Ca 'double-plus' SIMS dating resolves Klokken feldspar 40 K-40 Ar paradox[END_REF].

Important to the present study is the general recognition that different structural domains in Kfeldspar make them susceptible to variable resetting with disordered parts more likely to retain Ar and the coarser perthitic textured and more Or-enriched parts more likely to be reset, in particular where this is fluid assisted (Harrison et al., 2010 and references therein).

In this context, therefore, we interpret the results of the 40 Ar/ 39 Ar dating of K-feldspar (Fig. 8) to indicate the following: 1) the older domains dated at ca. 24.20 Ma equate to the less unmixed and disordered (i.e., with higher Or compositions and dominated by cryptoperthite and film perthite) phases; and 2) the younger domains dated at <23.20 Ma represent areas that, as noted above, are characterized by having higher Or contents (i.e., record a lower temperature equilibration), more perthite, a more ordered structure, and both abundant pitting (i.e., decrepitated fluid inclusions) and inundated with preserved fluid inclusions. We suggest that these latter features of K-feldspar, although formed earlier in the paragenesis during cooling of the granite, essentially controlled later diffusion and/or fluid-mediated loss of Ar [START_REF] Parsons | Argon-loss by alkali feldspars[END_REF][START_REF] Parsons | 40 Ar/ 39 Ar thermochronology using alkali feldspars: real thermal history or mathematical mirage of microtexture?[END_REF]. Also significant is the noted presence of adularia veinlets in some K-feldspars (Fig. A6), which possibly equate paragenetically with the formation of the stage IV adularia as discussed below.

Timing of hydrothermal alteration and Sn (-Cu) mineralization

Greisenization of the granitic cupola occurred between 24.18 ± 0.24 Ma and 24.36 ± 0.24 Ma (2σ; Fig. 9) based on the 40 Ar/ 39 Ar plateau dates for hydrothermal muscovite, which are interpreted to record the Ar closure temperature of muscovite (ca. 400°C; [START_REF] Harrison | Diffusion of 40 Ar in muscovite[END_REF].

The resulting average 40 Ar/ 39 Ar age of 24.24 ± 0.24 Ma (2σ) is consistent within uncertainty with the previous K/Ar age of 23.60 ± 0.60 Ma (2σ), determined on the muscovite sample COCA-247 [START_REF] Kontak | Geochronological data for Tertiary granites of the southeast Peru segment of the central Andean tin belt[END_REF]. Furthermore, it indicates that the early greisen alteration, which is restricted to the upper part of the SRIC, was coeval with cooling of the parental intrusion. The fact that the quartz in sample COCA-247 is inundated with both monophase vapor and vapor-rich fluid inclusions with lesser halite-bearing fluid inclusion types, as discussed by [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF], reflects phase separation and thus also indicates a highlevel of granite emplacement (i.e., <615 bars or <2.3 km).

The greisen development is interpreted to be contemporaneous with the emplacement of quartz-tourmaline veins and breccias of pre-ore stage I, as shown by our new observations and previous descriptions [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Gialli | Early hydrothermal alteration stages at the giant San Rafael tin deposit[END_REF]Harlaux et al., 2021b).

The formation of the well-developed quartz-tourmaline veins and breccias, and variable abundances of both coarse radial tourmaline in K-feldspar and disseminated tourmaline in the granitic groundmass, possibly reflects a pulsing magmatic-hydrothermal system that could have been triggered by the injection of a B-rich silicate melt into a long-lived underlying magmatic reservoir [START_REF] Harlaux | Tourmaline as a Tracer of Late-Magmatic to Hydrothermal Fluid Evolution: The World-Class San Rafael Tin (-Copper) Deposit[END_REF]. This interpretation is corroborated by the occurrence of a tourmaline-bearing leucogranite plug in the northwestern part of the San Rafael granite having a more evolved geochemical composition and interpreted as a later B-rich intrusive phase of the SRIC [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]Harlaux et al., 2021b).

All four dated cassiterite samples represent the main ore stage II, the most important, but not the sole Sn depositional episode at San Rafael. These U-Pb cassiterite dates all overlap within uncertainty between 23.47 ± 0.53 Ma and 24.10 ± 0.37 Ma (2σ; Fig. 11). These are interpreted as crystallization ages owing to the elevated closure temperature for Pb diffusion in cassiterite (>600°C; [START_REF] Zhang | The closure of U-Pb isotope system in cassiterite and its reliability for dating[END_REF]. Importantly, the latter temperature is well above the inferred crystallization temperature of ca. 350-400°C estimated for San Rafael cassiterite from previous fluid inclusion and mineral chemical studies [START_REF] Palma | The San Rafael tin-copper deposit[END_REF][START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Wagner | Stable isotope constraints on ore formation at the San Rafael tin-copper deposit[END_REF]Prado Flores, 2015). This indicates that deposition of large amounts of cassiterite during the main ore stage II occurred during a short-lived hydrothermal pulse of <1 Myr duration after the emplacement and cooling of the SRIC and shortly after formation of the stage I quartz-tourmaline veins and breccias. Given the upper crustal emplacement level of the SRIC and the need to sustain temperatures of mineralization up to 350-400°C, the duration of stage II was likely on the order of <0.5 Myr, as has been demonstrated for short-lived mineralizing episodes in porphyry-type magmatic-hydrothermal systems (e.g., [START_REF] Chiaradia | How accurately can we date the duration of magmatic-hydrothermal events in porphyry systems? -An invited paper[END_REF][START_REF] Catchpole | Timing of porphyry (Cu-Mo) and base metal (Zn-Pb-Ag-Cu) mineralisation in a magmatic-hydrothermal system-Morococha district[END_REF][START_REF] Tapster | Rapid thermal rejuvenation of high-crystallinity magma linked to porphyry copper deposit formation; evidence from the Koloula Porphyry Prospect[END_REF][START_REF] Li | Cyclic magmatic-hydrothermal evolution in porphyry systems: High-precision U-Pb and Re-Os geochronology constraints on the Tibetan Qulong porphyry Cu-Mo deposit[END_REF][START_REF] Rottier | Multiple rejuvenation episodes of a silicic magma reservoir at the origin of the large diatreme-dome complex and porphyry-type mineralization events at Cerro de Pasco[END_REF][START_REF] Large | Copper-mineralised porphyries sample the evolution of a large-volume silicic magma reservoir from rapid assembly to solidification[END_REF].

The fact that the U-Pb cassiterite ages overlap within uncertainty with the 40 Ar/ 39 Ar plateau age of 23.81 ± 0.23 Ma obtained on sanidine from the pristine Antauta cordierite-biotite granitic dike located <12 km south of San Rafael [START_REF] Kontak | Petrogenesis of a Neogene shoshonite suite, Cerro Moromoroni[END_REF][START_REF] Sandeman | Lithostratigraphy, petrology and 40 Ar-39 Ar geochronology of the Crucero Supergroup[END_REF] possibly indicates a protracted magmatic activity until the main ore stage II. The precipitation of large amounts of cassiterite in the richly mineralized Sn lodes is interpreted as the result of mixing of Sn-rich magmatic brines exsolved from the underlying magma chamber with modified meteoric water, as supported by previous fluid inclusion, stable isotope, and mineral chemical studies [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Mlynarczyk | Zoned tourmaline associated with cassiterite: implications for fluid evolution and tin mineralization in the San Rafael Sn-Cu deposit, southeastern Peru[END_REF]Wagner et al., 2009;[START_REF] Harlaux | Tourmaline as a Tracer of Late-Magmatic to Hydrothermal Fluid Evolution: The World-Class San Rafael Tin (-Copper) Deposit[END_REF]Harlaux et al., , 2021c;;[START_REF] Cazorla Martínez | Fluid evolution in the San Rafael Sn-Cu lode deposit[END_REF]. That the U-Pb ages for botryoidal and coarse-grained cassiterite cannot be unequivocally resolved within uncertainty corroborates the petrographic observations showing alternate layers of these two morphological types of cassiterite [START_REF] Mlynarczyk | San Rafael, Peru: Geology and structure of the worlds richest tin lode[END_REF][START_REF] Wagner | Stable isotope constraints on ore formation at the San Rafael tin-copper deposit[END_REF].

The 40 Ar/ 39 Ar data obtained on adularia from stages III and IV yielded within uncertainty identical plateau dates between 22.72 ± 0.11 Ma and 22.29 ± 0.24 Ma (2σ; Fig. 10), which are consistent with a previous K/Ar age of 22.60 ± 0.50 Ma (2σ) on adularia intergrown with base-metal sulfides of stage III [START_REF] Clark | Occurrence and age of tin mineralization in the Cordillera Oriental, southern Peru[END_REF]. The new adularia dates are interpreted as crystallization ages and thus record cooling of the hydrothermal system below the Ar closure temperature of orthoclase (ca. 300-350°C; [START_REF] Cassata | Systematic variations of argon diffusion in feldspars and implications for thermochronometry[END_REF]. This indicates that the quartz-carbonate-adularia±fluorite veins of stage IV, partly overlapping with the polymetallic (Cu-Zn-Pb-Ag-Sn) mineralization of stage III, record the youngest dated hydrothermal stage in the San Rafael deposit. Therefore, the geochronological data demonstrate that this late hydrothermal event in the lifespan of the magmatic-hydrothermal system postdated by ca. 1 Myr the deposition of the main Sn ore stage. As we already noted, the spread of the younger 40 Ar/ 39 Ar age spectra between ca. 23.70 and 22.50 Ma for K-feldspar phenocrysts (Fig. 8) is interpreted to record successive pulses of hydrothermal fluids between stages II and IV, including introduction of additional Sn during stage III.

To summarize, the San Rafael magmatic-hydrothermal system was active for an overall period of at least 2 Myr, from late Oligocene to early Miocene, following initial emplacement of the earliest granitic phase of the SRIC. The lifetime of the magmatic-hydrothermal system was likely sustained by protracted magmatic activity in the underlying reservoir (i.e., magma recharge) resulting in cyclic release of magmatic-hydrothermal pulses. The latest polymetallic stages postdating the main Sn ore stage by ca. 1 Myr reflect the waning of the hydrothermal system accompanied by additional incursion of meteoric groundwaters.

Trace elements in San Rafael cassiterite and comparison with the Bolivian tin belt

Trace element compositions of cassiterite from San Rafael are similar to the ones of other Oligocene-Miocene Sn deposits in the Bolivian tin belt (Fig. 13A; [START_REF] Gemmrich | Trace element composition and U-Pb ages of cassiterite from the Bolivian tin belt[END_REF].

Cassiterite is notably depleted in Nb, Ta, In, Ge, and Ga whose contents are comparable to those of cassiterite from the Bolivian Sn deposits [START_REF] Gemmrich | Trace element composition and U-Pb ages of cassiterite from the Bolivian tin belt[END_REF]. The highly variable Zr/Hf (4-41) and Y/Ho (2-27) ratios in cassiterite fall outside of the CHArge-and-RAdius-Controlled (CHARAC) field as defined by [START_REF] Bau | Controls on the fractionation of isovalent trace elements in magmatic and aqueous systems: evidence from Y/Ho, Zr/Hf, and lanthanide tetrad effect[END_REF]. This indicates trace element fractionation caused by different complex formation in aqueous solutions, as also shown for other hydrothermal oxides (e.g., Harlaux et al., 2018b;[START_REF] Schirra | Petrochronology of hydrothermal rutile in mineralized porphyry Cu systems[END_REF]. Similarly, the Nb/Ta ratio (7-3474) in cassiterite is extremely variable, which could result from fluid mixing, variable degrees of fluid-rock interaction, or chemical disequilibrium at the mineral/fluid interface [START_REF] Lerouge | Distribution of In and other rare metals in cassiterite and associated minerals in Sn±W ore deposits of the western Variscan Belt[END_REF][START_REF] Cheng | Controls on cassiterite (SnO2) crystallization: Evidence from cathodoluminescence, trace-element chemistry, and geochronology at the Gejiu Tin District[END_REF][START_REF] Bennett | Microstructural controls on the chemical heterogeneity of cassiterite revealed by cathodoluminescence and elemental X-ray mapping[END_REF]. The strong positive correlation between V and Sc observed in San Rafael cassiterite (Fig. 12G) supports the heterovalent coupled substitution Sc 3+ + V 5+ = 2Sn 4+ proposed by previous studies [START_REF] Cheng | Controls on cassiterite (SnO2) crystallization: Evidence from cathodoluminescence, trace-element chemistry, and geochronology at the Gejiu Tin District[END_REF][START_REF] Gemmrich | Trace element composition and U-Pb ages of cassiterite from the Bolivian tin belt[END_REF]. Additionally, a clear positive correlation is found between Fe and Ga (Fig. 12B), possibly reflecting the heterovalent substitution R 3+ + (Nb,Ta) 5+ = 2Sn 4+ where R 3+ = Fe 3+ , Ga 3+ [START_REF] Izoret | Caractérisation cristallochimique de la cassitérite des gisements d'étain et de tungstène de Galice[END_REF][START_REF] Tindle | Oxide minerals of the Separation Rapids rare-element granitic pegmatite group, northwestern Ontario[END_REF].

One of the most characteristic features of the Sn mineralization at San Rafael is the occurrence of large amounts of botryoidal cassiterite ("wood tin"), which is restricted to the stage II of the paragenetic sequence of the deposit. Botryoidal cassiterite has been mainly described in Mexican-type rhyolite-hosted Sn deposits in New Mexico, Nevada, Alaska, Mexico, Bolivia, Russia, Tasmania, and Malaysia (Taylor, 1979;[START_REF] Hutchison | Geology of Tin Deposits in Asia and the Pacific[END_REF]. The conditions required for the formation of "wood tin" are uncertain and previous work proposed several explanations, including supergene oxidation from stannite, crystallization from Sn-rich colloidal silica gels, low temperature (<150°C) encrustations/infillings, or rapid nucleation from supersaturated solutions (e.g., [START_REF] Lufkin | Chemistry and mineralogy of wood-tin, Black Range[END_REF]Taylor, 1979;[START_REF] Hosking | The occurrence, nature and genesis of wood tin in south-west England[END_REF].

Interestingly, the trace element compositions of botryoidal and coarse-grained cassiterite from San Rafael are similar, differing only by variable slopes of element correlations in binary diagrams (Fig. 12), such as Fe vs In, Ge vs Ga, or Ti vs Nb. These variable element ratios may indicate contrasting compositions of the Sn-precipitating fluids during deposition of botryoidal and coarse-grained cassiterite, or variable degrees of local fluid-rock interactions. The trace element profiles performed in cassiterite reveal fluctuating concentrations of one to three orders of magnitude for Sc, Ti, V, Fe, Ga, Nb, In, W, and U along the crystal growth direction (Figs.

14-15). Such variations suggest evolving physicochemical fluid conditions in the hydrothermal system over time, possibly caused by repeated mixing of Sn-bearing magmatic brines with meteoric waters and/or fluid chemical disequilibrium induced by rapid nucleation and crystal growth.

The REE spectra of San Rafael cassiterite are characterized by concave tetrad effects and negative Ce and Eu anomalies similar to cassiterite from the Bolivian tin belt (Fig. 13B; [START_REF] Gemmrich | Trace element composition and U-Pb ages of cassiterite from the Bolivian tin belt[END_REF]. Highly irregular chondrite-normalized REE patterns in hydrothermal minerals combining concave and convex tetrads have been linked to fluid immiscibility and REE liquid-vapor fractionation (e.g., [START_REF] Monecke | Unusual rare earth element fractionation in a tin-bearing magmatic-hydrothermal system[END_REF]. In particular, the development of negative Eu anomalies and concave tetrads in hydrothermal minerals is attributed to precipitation from F-rich vapors that separated from a single-phase magmatic fluid [START_REF] Monecke | Unusual rare earth element fractionation in a tin-bearing magmatic-hydrothermal system[END_REF]. Although evidence of boiling was demonstrated during the early, pre-ore evolution of the San Rafael magmatic-hydrothermal system, the precipitation of cassiterite resulted essentially from the mixing between Sn-rich magmatic brines and modified meteoric waters [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Mlynarczyk | San Rafael, Peru: Geology and structure of the worlds richest tin lode[END_REF][START_REF] Wagner | Stable isotope constraints on ore formation at the San Rafael tin-copper deposit[END_REF][START_REF] Harlaux | Tourmaline as a Tracer of Late-Magmatic to Hydrothermal Fluid Evolution: The World-Class San Rafael Tin (-Copper) Deposit[END_REF]Harlaux et al., , 2021c)).

Experimental and empirical studies of hydrothermal systems indicate that REE-Cl complexes partition readily into brines relative to vapors and that HREE are preferentially fractionated over LREE into the vapor phase [START_REF] Shmulovich | Experimental determination of REE fractionation between liquid and vapour in the systems NaCl-H2O and CaCl2-H2O up to 450[END_REF][START_REF] Möller | Partitioning of rare earth elements, yttrium, and some major elements among source rocks, liquid and vapor of Larderello-Travale Geothermal Field[END_REF][START_REF] Möller | Vapour/liquid fractionation of rare earths, Y 3+ , Na + , K + , NH4 + , Cl -, HCO3 -, SO4 2and borate in fluids from the Piancastagnaio geothermal field[END_REF]. Accordingly, the Sn-rich magmatic brines acting as the main mineralizing fluid at San Rafael should be enriched in LREE relative to HREE resulting in precipitation of LREE-rich cassiterite. This fractionation is not observed in botryoidal and coarse-grained cassiterite which show similar (La/Yb)N ratios (0.50-4.14) and uniformly low total REE contents (1.3-9.3 ppm).

This inconsistency suggests a crystallographic control on REE incorporation in cassiterite as also described in other minerals like wolframite [START_REF] Xiong | Ore-forming mechanism of quartz-vein-type W-Sn deposits of the Xitian district in SE China: Implications from the trace element analysis of wolframite and investigation of fluid inclusions[END_REF]Harlaux et al., 2018b;[START_REF] Zhang | In-situ LA-ICP-MS trace element analyses of scheelite and wolframite: Constraints on the genesis of veinletdisseminated and vein-type tungsten deposits[END_REF]. Indeed, the ionic radii of REE (La 3+ = 1.03 Å; Lu 3+ = 0.86 Å) are much larger than that of Sn 4+ (0.69 Å) in octahedral coordination [START_REF] Shannon | Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides[END_REF], suggesting that REE incorporation into cassiterite is crystallographically limited. Another explanation may be the co-crystallization of REE-bearing hydrothermal minerals (e.g., chlorite, monazite, apatite) resulting in low REE contents in cassiterite.

The pronounced negative Ce and Eu anomalies also indicate that these two elements are not easily incorporated into cassiterite due to their large ionic radii and the prevalent stability of Eu 2+ (1.17 Å) and Ce 3+ (1.01 Å) over Eu 3+ (0.95 Å) and Ce 4+ (0.87 Å), respectively, in hydrothermal fluids [START_REF] Migdisov | Hydrothermal transport, deposition, and fractionation of the REE: Experimental data and thermodynamic calculations[END_REF][START_REF] Liu | Revisiting the hydrothermal geochemistry of europium (II/III) in light of new in-situ XAS spectroscopy results[END_REF]. Furthermore, experimental work demonstrated that the LREEs are more stable and, thus, more mobile than the HREEs in chloride-bearing aqueous solutions and that this difference in stability increases with increasing temperature [START_REF] Migdisov | Hydrothermal transport, deposition, and fractionation of the REE: Experimental data and thermodynamic calculations[END_REF]. Another work showed that the REE contents and the LREE/HREE ratios of cassiterite are strongly influenced by the associated mineral assemblage, the fluid chemistry, and the composition of the host rocks [START_REF] Plimer | Trace and rare earth elements in cassiteritesources of components for the tin deposits of the Mole Granite[END_REF]. Consequently, the REE composition of cassiterite likely reflects the combination of these different variables and, therefore, is difficult to interpret regarding the geologic process occurring during Sn deposition.

Conclusions

This study demonstrates that the world-class San Rafael Sn (-Cu) deposit formed in a protracted geological period of at least 2 Myr, from late Oligocene to early Miocene, including the following sequence of major events:

(1) Crystallization of the medium-to coarse-grained biotite-cordierite granitic pluton by ca.

24.50 Ma which intruded into host Ordovician metasedimentary rocks. The least disturbed biotite sample from the megacrystic monzogranite yielded an 40 Ar/ 39 Ar plateau date of 24.10 ± 0.26 Ma, which constrains the time of cooling of the upper part of the stock to <300°C, i.e., the Ar closure temperature of this phase. Such a rapid cooling is consistent with the petrographic features of the granitic stock (e.g., porphyritic dikes with quenched textures, granophyre/graphic intergrowths) and the Al/Si ordering of the K-feldspar megacrysts, which collectively indicate a shallow crustal emplacement (~2-3 km paleodepth).

(2) Localized greisenization in the granite cupola, which was coeval with the cooling of the parental intrusion, occurred at 24.24 ± 0.24 Ma, based on muscovite average 40 Ar/ 39 Ar plateau ages. This event was contemporaneous with emplacement of quartz-tourmaline veins and breccias of pre-ore stage I. The fact that minor amounts of tourmaline are present in the greisen provides a genetic link to the subsequent onset of alteration and mineralization.

Tourmalinization possibly resulted from a pulsing magmatic-hydrothermal system caused by the injection of B-rich silicate melt into the underlying crystal mush reservoir.

(3) Deposition of Sn during stage II, the main ore stage, is constrained by LA-ICP-MS U-Pb dating of cassiterite between 24.10 ± 0.37 Ma and 23.47 ± 0.53 Ma. This reflects successive hydrothermal pulses that occurred <1 Myr after the crystallization of the main granitic phases of the SRIC and shortly after emplacement of stage I quartz-tourmaline veins and breccias. The duration of this event is poorly constrained by the associated uncertainties but given the upper crustal emplacement level and the need to sustain fluid temperatures of up to 350-400°C, its duration was likely on the order of <0.5 Myr. This study provides further evidence that the present-day exposed level of the San Rafael granite was a passive host for the Sn mineralization and only provided the structural focusing for mineralizing fluids derived from a deeper part of the magmatic system. Botryoidal and coarse-grained cassiterite from stage II are characterized by similar trace element compositions with fluctuating metal contents across growth banding. These variations suggest significant changes of physicochemical conditions of the hydrothermal system during cassiterite precipitation, likely caused by rapid and repeated mixing between magmatic fluids and meteoric groundwaters. [START_REF] Palma | The San Rafael tin-copper deposit[END_REF][START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF][START_REF] Mlynarczyk | San Rafael, Peru: Geology and structure of the worlds richest tin lode[END_REF]Mlynarczyk and [START_REF] Kontak | The magmatic and metallogenetic evolution of a craton-orogen interface: The Cordillera de Carabaya[END_REF] and details are provided therein and in [START_REF] Kontak | The influences of fluid and rock compositions, and tectono-thermal processes on Al-Si distribution in alkali feldspars in granitoid rocks[END_REF]. The samples selected for dating are indicated by numbers, all of which have COCA prefix. Note the following: 1) glassy samples from the same age and petrologically similar Antauta granitic dike (see text for discussion) are disordered and equate to sanidine structurally; 2) samples from the granitic rocks (i.e., ring dikes) at Quenamari have more disordered structures than the main granite; 3) metasomatic samples are more orthoclaseenriched compared to the fresh samples, in particular for the San Rafael intrusion; and 4) for some samples, the least altered and their metasomatic equivalents are plotted. Fig. 6. 40 Ar/ 39 Ar age spectra for biotite from the San Rafael megacrystic cordierite-biotite granite showing plateau ages. The reported degree of alteration of the host rock and K contents of biotite are from [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]. All ages are reported at 2σ level of confidence. Fig. 7. 40 Ar/ 39 Ar age spectra for biotite from the San Rafael megacrystic cordierite-biotite granite showing disturbed patterns. The reported degree of alteration of the host rock and K contents of biotite are from [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]. All ages are reported at 2σ level of confidence.

Figure captions

Fig. 8. 40 Ar/ 39 Ar age spectra for K-feldspar phenocrysts from the San Rafael megacrystic cordierite-biotite granite showing U-shaped pattern and pseudo-plateau ages. The reported degree of alteration of the host rock and orthoclase molar contents (mol.% Or) are from [START_REF] Kontak | Genesis of the giant, bonanza San Rafael lode tin deposit, Peru: Origin and significance of pervasive alteration[END_REF]. All ages are reported at 2σ level of confidence. Fig. 9. 40 Ar/ 39 Ar age spectra for muscovite from the San Rafael deposit yielding plateau ages.

The reported degree of alteration of the host rock and K contents of muscovite are from [START_REF] Palma | The San Rafael tin-copper deposit[END_REF] and [START_REF] Kontak | The magmatic and metallogenetic evolution of a craton-orogen interface: The Cordillera de Carabaya[END_REF]. All ages are reported at 2σ level of confidence. Fig. 10. 40 Ar/ 39 Ar age spectra for adularia from the San Rafael deposit yielding plateau ages.

The reported degree of alteration of the host rock and K contents of adularia are from [START_REF] Palma | The San Rafael tin-copper deposit[END_REF] and this work. All ages are reported at 2σ level of confidence. [START_REF] Mcdonough | The composition of the Earth[END_REF]. The grey field correspond to the range of concentrations for cassiterite from Oligocene-Miocene Sn deposits in the Bolivian tin belt [START_REF] Gemmrich | Trace element composition and U-Pb ages of cassiterite from the Bolivian tin belt[END_REF]. (1983), and (5) [START_REF] Kontak | Petrogenesis of a Neogene shoshonite suite, Cerro Moromoroni[END_REF].

  age spectra are shown in Figure8. In addition, the Al-Si ordering for these samples is summarized in Figure5. All K-feldspar samples show disturbed 40 Ar/ 39 Ar incremental heating spectra with quasi-U-shaped patterns. Sample COCA-165B (~88 mol.% Or) yielded 40 Ar/ 39 Ar apparent dates between ca.33.6 Ma and ca. 22.4 Ma but defines low-and high-temperature pseudo-plateaus dates of 22.50 ± 0.40 Ma and 24.20 ± 0.40 Ma, respectively (2σ; Fig.8A). Sample COCA-190 (~93 mol.% Or) yielded 40 Ar/ 39 Ar apparent dates ranging from ca. 31.5 Ma to ca. 23.0 Ma, but also defines low-and high-temperature pseudo-plateaus dates of 23.15 ± 0.40 Ma and 24.15 ± 0.40 Ma, respectively (2σ; Fig.8B). Sample COCA-198 (~85 mol.% Or) yielded 40 Ar/ 39 Ar apparent dates ranging from ca. 31.6 Ma to ca. 22.3 Ma, and again defines low-and high-temperature pseudo-plateau dates of 22.80 ± 0.40 Ma and 24.15 ± 0.40 Ma, respectively (2σ; Fig.8C). Sample COCA-408A (~76 mol.% Or), which interestingly has the most disordered structure of the dated K-feldspar samples (Fig.5), yielded 40 Ar/ 39 Ar apparent dates between ca. 34 Ma and ca. 11.6 Ma, defining low-and high-temperature step dates of 23.70 ± 0.40 Ma and 26.50 ± 0.40 Ma, respectively (2σ; Fig.8D).

  with the respective age spectra shown in Figures 9 and 10. All samples show at least five consecutive steps defining plateaus with MSWD values ≈ 1.

( 4 )

 4 Formation of the polymetallic sulfide mineralization of stage III and the late quartzcarbonate-fluorite stage IV is constrained by 40 Ar/ 39 Ar dating of adularia between 22.72 ± 0.11 Ma and 22.29 ± 0.24 Ma. This timing is further supported by the U-shaped 40 Ar/ 39 Ar spectra for K-feldspar phenocrysts from the cordierite-biotite megacrystic granite and their partial resetting which have minima ages at ca. 22.50 Ma. These age spectra are typical of excess Ar in a fluid-rich open system and are in agreement with hydrothermal circulations during stages II to IV, including introduction of additional Sn during stage III. The geochronological data indicate therefore that the magmatic-hydrothermal system remained active for ca. 1 Myr following the main Sn ore stage, resulting in polymetallic sulfide mineralization.

Fig. 1 .

 1 Fig. 1. Geological map and cross-section of San Rafael district, southeast Peru. (A) Location

Fig. 2 .Fig. 3 .

 23 Fig. 2. Photographs of representative samples from San Rafael showing the different stages of

Fig. 4 .

 4 Fig. 4. Revised paragenetic sequence of the San Rafael deposit incorporating previous

Fig. 5 .

 5 Fig. 5. Summary of X-ray diffraction data for K-feldspars from the San Rafael and Quenamari

Fig. 11 .

 11 Fig. 11. Tera-Wasserburg U-Pb Concordia diagrams for cassiterite from the San Rafael deposit.

Fig. 12 .

 12 Fig. 12. Variation diagrams of selected trace elements in cassiterite from the San Rafael deposit.

Fig. 13 .

 13 Fig. 13. (A) Trace element contents of cassiterite from the San Rafael deposit normalized to

Fig. 14 .

 14 Fig. 14. (A) Transmitted-light (TL) photomicrograph and (B) cathodoluminescence (CL)

Fig. 15 .

 15 Fig. 15. (A) Transmitted-light (TL) photomicrograph and (B) cathodoluminescence (CL)

Fig. 16 .

 16 Fig. 16. Summary of geochronological data for the San Rafael Sn (-Cu) deposit. Uncertainties

Cordierite

  Nb, 95 Mo, 107 Ag, 111 Cd, 113 In, 117 Sn, 139 La, 140 Ce, 141 Pr, 145 Nd, 147 Sm, 153 Eu, 157 Gd, 159 Tb, 163 Dy, 165 Ho, 167 Er, 169 Tm, 173 Yb, 175 Lu, 178 Hf, 181 Ta, 186 W, 206 Pb, 207 Pb, 208 Pb, 232 Th, and 238 U. Dwell times were set to 10 ms, except for 27 Al, 29 Si, 45 Sc,

Chl Chl Chl Chl Fl Fl Fl Fl Adl Adl Adl Adl Ccp Ccp Ccp Ccp Py Py Adl Adl Ab Ab Kfs Kfs Kfs Kfs Qtz Qtz Qtz Qtz Ms Ms Ms Ms Tur Tur Tur Tur Dum Dum Dum Dum Tur Tur Tur Tur Qtz Qtz Qtz Qtz Ap Ap Ap Ap Bt Bt Adl Adl Qtz Qtz Qtz Qtz Bt Bt Bt Bt Kfs Kfs Pl Pl Pl Pl Ms Ms Ms Ms Ap Ap Ap Ap Ms Ms Ms Ms Qtz Qtz Qtz Qtz Cst Cst Qtz Qtz Qtz Qtz Cst Cst Chl Chl Ms Ms Chl Chl Ap Ap Ap Ap Py Py Cst Cst Cst Cst Chl Chl Chl Chl Qtz Qtz Qtz Qtz Cst Cst Cst Cst Cst Cst Cst Cst Chl Chl Chl Chl Kfs Kfs Ab Ab Ab Ab Bt Bt Chl Chl Chl Chl Ab Ab Ms Ms

	TL	QEMSCAN	TL	QEMSCAN
	TL	QEMSCAN	TL	QEMSCAN
	TL	QEMSCAN	TL	QEMSCAN

Acknowledgments

This research was supported by a Swiss National Science Foundation grant (S19053_169901) to Lluís Fontboté, the company Minsur S.A, and by Natural Sciences and Engineering Research Council of Canada grants to Alan H. Clark and Edward Farrar. Logistic support in the field was

provided by the geologist teams from Minsur S.A., who are gratefully acknowledged here. This contribution is dedicated to the memory of Edward Farrar, pioneering geochronologist, who for over forty years provided the temporal framework essential to the Queen's University Central Andean Metallogenetic Project. The authors are also grateful to Douglas A. Archibald, Yanshao Chen, Hamish A. Sandeman, and Hardolph A. Wasteneys for providing technical support with acquisition of the geochronological data. This paper benefited from the critical comments of Jay Thompson on an earlier version of the manuscript. Finally, we would like to thank three anonymous reviewers, as well as the Associate Editor Massimo Chiaradia and the Editor-in-Chief Larry Meinert for their constructive comments, which helped to improve the original manuscript.