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Payún Matrú

Payún Matrú is a shield volcano in the Reserva Provincial La Payunia of the Malargüe Department, south of the Mendoza Province in Argentina. It lies in the back-arc region of the Andean Volcanic Belt, and was formed by the subduction of the Nazca Plate beneath the South American Plate. Payún Matrú, along with the Llancanelo, Nevado and Salado Basin volcanic fields, form the Payenia province. It has been proposed as a World Heritage Site since 2011.

Payún Matrú developed on sediment and volcanic rocks ageing from the Mesoproterozoic to the Tertiary periods. It consists of a large shield volcano capped by a caldera, formed during a major eruption between 168,000 and 82,000 years ago, a high compound volcano (known as Payun or Payun Liso), and two groups of scoria cones and lava flows. The Pleistocene Pampas Onduladas lava flow reaches a length of 167 - 181 km and is the world's longest Quaternary lava flow.

Volcanic activity at Payún Matrú commenced during the Plio-Pleistocene period, and generated lava fields such as Pampas Onduladas, the Payún Matrú shield volcano and the Payun volcano. After the formation of the caldera, volcanism continued both within the caldera as lava domes and flows, and outside of it with the formation of scoria cones and lava flows east and especially west of Payún Matrú. Volcanic activity continued into the Holocene until about 515 years ago; oral tradition of local inhabitants contains references to earlier eruptions.

Name
In local dialect, the term Payún or Paium means "bearded", while the term Matru translates as "goat". The field is sometimes also known as Payenia.

Regional
Payún Matrú lies in the Malargüe Department of the Mendoza Province, in Argentina. The area is inhospitable due to the lack of usable water and high elevation. Nevertheless, there are many paved roads such as National Route 40 which passes west of the field, and National Route 186 which runs around its northern and eastern parts. The volcano is within the Reserva Provincial La Payunia. Owing to the variety of volcanic landforms, the province was included in the 2010 Tentative List of UNESCO World Heritage Sites and a number of potential geosites have been identified at Payún Matrú itself.

The active field is part of the backarc area of the Southern Volcanic Zone, a 1000 km long volcanic arc and one of four eruptive belts in the Andes; the other three being the Northern Volcanic Zone, the Central Volcanic Zone and the Austral Volcanic Zone. Other volcanoes in the region include the Laguna del Maule, almost due west from Payún Matrú.

Local
Payún Matrú is a 15 km shield volcano whose foot coincides with the 1750 m elevation contour and which extends mainly east–west; rising about 2 km above the surrounding terrain it covers about 5200 km2 of land with lava and has diverse landforms. Ignimbrites cover and flatten its northern and eastern slopes, while in the west and south lava domes and coulées predominate; these have often rough surfaces and are difficult to traverse. The lower slopes are more gentle and covered by Pleistocene-Holocene lava flows. Wind erosion has created flutes, grooves and yardangs within the ignimbrites, such as in the western sector where yardangs reach heights of 8 m and widths of 100 m. The total volume of this shield is about 240 km3. A 7 - 8 km and 480 m caldera lies in the summit region of the shield and covers a surface area of about 56 km2. It is surrounded by several peaks, which clockwise from north include the 3650 m Nariz/Punta del Payún, the Punta Media, the 3450 m Punta Sur and the approximately 3700 m Cerro Matru or Payen. In the field however Cerro Matru appears smaller than Nariz. The caldera was once 8 - 9 km wide but erosion of its flanks and later activity have reduced its size and buried the rim below coulées, lava domes, lava flows and pumice cones that were emplaced after the caldera collapse. The exception are the northern and southern walls which are almost vertical; remnants of old andesitic and trachyandesitic volcanism crop out there. The caldera also contains a permanent lake known as "Laguna" that is fed by snowmelt and by occasional rainfall.

Matrú's highest active point field is the 3796 m high, conical, eroded Payun stratovolcano. It is also known as Payun Liso, Payún and Payún Liso. This volcano rises 1.8 km from the southern side of Payún Matrú, 10 km away from the caldera. It has a summit crater open to the north and it has a volume of about 40 km3.

Payún Matrú volcanic field
Aside from the caldera, the field contains about 300 individual volcanic vents with diverse morphologies distributed in a western Los Volcanes group that reaches to the Rio Grande River and the eastern Guadaloso and El Rengo groups. These fields are also known as West Payún Matrú or West Payén and East Payún Matrú or East Payén, respectively. Two further ruptures, known as "Chapua" and "Puente", have been identified east of Payún Matrú. All these groups include fissure vents, lapilli cones, scoria cones and strombolian cones. These edifices are up to 225 m high and are associated with lava flows and pyroclastic units; the vents in the Los Volcanes group are spread across two separate belts. Wind-driven ash transport has formed ash tails at individual vents.

Older lava flows have pahoehoe surfaces with lava tubes and pressure ridges, while Holocene flows are more commonly aa lava with blocky surfaces. Some flows have reached the Rio Grande River west of Payún Matrú, damming it; the river later cut through and formed table-like landforms and canyons. One of these is a slot canyon known as La Pasarela, where the structures of lava flows such as joints in the rocks and vesicles are clearly visible. The entire field covers an area of over 12000 km2 and some of its flows have reached the Llancanelo Lake north of Payún Matrú and the Salado River in the east. The estimated volumes of the entire Payún Matrú volcano are as large as 350 km3; the volcanic edifice was generated mostly through Strombolian and Hawaiian eruptions. The cones are aligned along easterly or northeasterly lineaments which correlate with geological structures in the basement, and appear to reflect the tectonic stresses underground. Among these lineaments is the La Carbonilla fracture which runs in east–west direction and crops out in the eastern part of the field; in the central sector it is hidden by the caldera and in the western it is buried by lava flows. The La Carbonilla fracture is a fault that appears to have been an important influence on the development of the Payún Matrú complex in general. Fissural ridges and elongated chains of vents and cones highlight the control that lineaments exercise on the volcanic eruptions. In the summit area, pumice cones are aligned along the caldera rim.

Among the cones in Payún Matrú are the Plio-Pleistocene (5.333 million years ago until 11,700 years ago ) Morados Grandes east and the cones around Pihuel volcano northeast of the field, respectively; the Guadalosos, La Mina and Montón de Cerros cones in the northern part of the field; and the Holocene cones in the eastern and western part of the field. Among these the Los Morados, Morado Sur and Volcán Santa María cones in the eastern and northeastern part of the field are uneroded and are probably of recent age. These cones are the source of conspicuous black lava flows in the western part of the field; some lava flows are over 30 km long.
 * Los Morados is a complex of scoria cones and vents of different ages which during its emplacement underwent a sector collapse, intense Strombolian activity and a lava flow-induced rafting and re-healing of its slopes.
 * On the southeast and east Los Morados is bordered by a lapilli plain, the Pampas Negras, which was formed by fallout of Strombolian eruptions and is being reworked by wind with the formation of dunes.
 * Morado Sur consists of two aligned cones that formed in the same eruption and are covered with reddish deposits; it also features several vents and lava flows.
 * Volcán Santa María is a cone with a small crater and also covered with red scoria and lava bombs. It is 180 m high and is associated with an area called "El Sandial", where lava bombs have left traces such as impact craters and aerodynamically deformed rocks.

Pampas Onduladas and other giant lava flows
Payún Matrú is the source of the longest Quaternary (last 2.58 million years ago ) lava flow on Earth, the Pampas Onduladas lava flow in the eastern and northern sector of the volcanic field. The flow originates on the eastern side of the volcanic field in the La Carbonilla fault and eventually splits up into a shorter ("Llancanelo lava flow", 60 - 63 km long) northwestern and the longer southeastern branch which reaches all the way to an alluvial terrace of the Salado River in the La Pampa Province.

This compound lava flow moved over a gentle terrain and is covered by lava rises and lava tumuli especially in areas where the flow encountered obstacles in the topography. There is some variation in its appearance between a wide, leveled initial proximal sector and a more sinuous distal sector. The unusually fast flowing lava under the influence of its low viscosity and of a favourable topography eventually accumulated to a volume of at least 7.2 km3, a surface area of about 739 km2 and depending on the measurement a length of 167 - 181 km. The process by which such long lava flows form has been explained as "inflation" whereby lava forms a crust that protects it from heat loss; the so protected lava flow eventually inflates from the entry of new magma, forming a system of overlapping and interconnected lava flow lobes. Such lava flows are known as "sheet flows". Parts of the Pampas Onduladas lava flow have been buried by more recent lava flows.

Together with the Þjórsá Lava in Iceland and the Toomba and Undara lava flows in Queensland, Australia, it is one of only a few Quaternary lava flows that reached a length of over 100 km and it has been compared to some long lava flows on Mars. Southwest from Pampas Onduladas lie the 181.2 km long Los Carrizales lava flows, which have in part advanced to even larger distances than Pampas Onduladas but owing to a straighter course are considered to be shorter than the Pampas Onduladas lava flow, and the La Carbonilla lava flow which like Los Carrizales propagated southeastward and is located just west from the latter. Additional large lava flows are located in the western part of the field and resemble the Pampas Onduladas lava flow, such as the El Puente Formation close to the Rio Grande River of possibly recent age. Long lava flows have also been produced by volcanic centres directly south of Payún Matrú, including the 70 - 122 km long El Corcovo, Pampa de Luanco and Pampa de Ranquelcó flows.

Hydrography and non-volcanic landscape
Apart from the lake in the caldera, the area of Payún Matrú is largely devoid of permanent water sources, with most water sites that draw in humans being either temporary so-called "toscales" or ephemeral. Likewise, there are no permanent rivers in the field and most of the precipitation quickly seeps into the permeable or sandy ground. The whole massif is surrounded by sandy plains, which are simply volcanic rocks covered by aeolian sediments; the plains also feature small closed basins which are also found in the lavic area.

Geology
West of South America, the Nazca Plate and the Antarctic Plate subduct beneath the South America Plate at a rate of 66 - 80 mm/year, giving rise to the Andean volcanic belt. The volcanic belt is not continuous and is interrupted by gaps where the subduction is shallower and the asthenosphere between the two plates missing. North of the Payún Matrú, flat slab subduction takes place; in the past flat slab subduction occurred farther south as well and had noticeable influence on magma chemistry. In general, the mode of subduction in the region over time has been variable.

There is evidence of Precambrian (older than 541 ± 0.1 million years ago ) and Permian-Triassic (298.9 ±0.15 to 201.3 ±0.2 million years ago ) volcanism (Choique Mahuida Formation) in the region, but a long hiatus separates them from the recent volcanic activity which started in the Pliocene (5.333–2.58 million years ago ). At that time, the basaltic El Cenizo Formation and the andesitic Cerro El Zaino volcanics were emplaced. This kind of calcalkaline volcanic activity is interpreted to be the consequence of flat slab subduction during the Miocene (23.03-5.333 million years ago ) and Pliocene, and took place between twenty and five million years ago. Later during the Pliocene and Quaternary the slab steepened, and probably as a consequence volcanism in the land above increased, reaching a peak between eight and five million years ago.

Local
The basement rock underneath Payún Matrú is formed by Mesoproterozoic (1,600–1,000 million years ago ) to Triassic rocks of the San Rafael Block, Mesozoic (251.902 ± 0.024 to 66 million years ago ) to Paleogene sediments of the Neuquén Basin and Miocene lava flows such as the Tertiary Patagonian basalts. The Andean orogeny during the Miocene has folded and deformed the basement, creating basins and uplifted basement blocks, and the Malargüe fold and thrust belt underlies part of the volcanic field. Oil has been drilled close to the volcanic field from sediments of Mesozoic age.

Payún Matrú is part of the backarc volcanic province, 200 km east of the Andes and 530 km east of the Peru-Chile Trench. The volcanic activity still relates to the subduction of the Nazca Plate beneath the South America Plate, however; one proposed mechanism is that a Miocene change in the subduction regimen led to the development of extensional tectonics and of faults that form the pathways for magma ascent, while other mechanisms envisage changes in mantle characteristics. Other volcanic fields in the region are the Llancanelo volcanic field, the Nevado volcanic field and Salado Basin volcanic field; the first two lie north of Payún Matrú and the last south. These fields are subdivided on the basis of geochemical differences and consist of two stratovolcanoes (Payún Matrú itself and Nevado) and many monogenetic volcanoes. The volcanic field is part of the larger Payunia volcanic province, which covers an area of about 36000 km2 in the Provinces of La Pampa, Mendoza and Neuquén and is also known as the Payenia or Andino-Cuyana volcanic province. Monogenetic volcanism of mainly basaltic composition has been active here for millions of years accompanied by the formation of several polygenetic volcanoes and volcanoes like Agua Poca, generating more than eight hundred monogenetic cones although historical eruptions have not been observed. Further south are the Chachahuen and Auca Mahuida volcanoes, while the Tromen volcano is located southwest from Payún Matrú.

Lava and magma composition
The volcanic field has produced rocks with composition ranging from alkali basalts over basalts, trachyandesite, basaltic trachyandesite, trachybasalt and trachyte to rhyolite. They define a calc-alkaline volcanic suite with some variation between the various volcanic centres; Los Volcanes is formed mainly by calc-alkaline magmas while Payun and Payún Matrú are more potassium-rich and shoshonitic. The volcanic rocks contain variable amounts of phenocrysts, including alkali feldspar, amphibole, apatite, biotite, clinopyroxene, olivine, plagioclase and sanidine, but not all phenocryst phases can be found in every rock formation. Magma temperatures of 1122 - 1276 C have been inferred.

Volcanic rocks erupted at Payún Matrú resemble ocean island basalt volcanism, implying a deep origin of the magma although a shallow origin cannot be ruled out. Magnetotelluric observations indicate the presence of a "plume"-like structure that rises from 200 - 400 km depth close to the edge of the Nazca Plate slab to underneath Payún Matrú; it may indicate that magma erupted in the volcanic field originates at such depths which would explain the ocean island basalt-like composition.

The magma ejected at Payún Matrú originates during partial melting of enriched mantle; the resulting melts then undergo crystal fractionation, assimilation of crustal material and magma mixing in magma chambers. The magmas eventually reach the surface through deep faults. The edifice of Payún Matrú acts as an obstacle to magmas ascending to the surface; this is why only evolved magmas are erupted in the caldera area of Payún Matrú while basic magmas reached the surface mainly outside of the main edifice.

Obsidian from Payún Matrú has been found in archeological sites, although its use was not widespread in the region perhaps owing to its low quality, the difficulty of accessing the volcanic complex and that human activity in Payunia only began comparatively late in the Holocene and mostly from the margins of the region. Further, Payun volcano is notable for large crystals of hematite pseudomorphs which originated in fumaroles.

Climate, soils and vegetation
The climate at Payún Matrú is cold and dry with strong westerly winds. Annual temperature varies between 2 and 20 C while the average temperature in the wider region is about 15 C and the average annual precipitation amounts to 200 - 300 mm/year. Generally, the area of Payún Matrú is characterized by a continental climate with hot summers especially at lower elevations and cold winters especially at higher elevations. The climate is dry owing to the rainshadow effect of the Andes which block moisture bearing winds from reaching Payún Matrú, and strong winds and the evaporation associated with them reinforce the dryness. In the westerly part of the volcanic field most precipitation falls during winter under the influence of the Andes, while the eastern part has most precipitation occurring during summer. The higher parts of Payún Matrú may have risen above the snowline during ice ages, and periglacial landforms have been observed. Palynology data from south of the region indicate that the climate has been stable since the Late Pleistocene.

The vegetation in the volcanic field is mostly characterized by sparse bushes as well as herbaceous vegetation but few trees, and is classified as xerophytic. Soils are shallow and are mainly rocky to loess-like. Representative plant genera are Opuntia cactus and Poa and Stipa grasses. Payún Matrú is a refuge for a number of animals such as the armadillos, black-chested buzzard-eagle, condors, Darwin's rhea, guanaco, mara, Pampas fox or South American gray fox, puma and Southern viscacha. Some lizards may have evolved on the volcanoes.

Eruptions

The geological history of the Payún Matrú volcanic field is poorly dated but the field has been active since Pliocene at least. The older volcanism appears to be located in the eastern part of the field where ages of 0.95 ± 0.5 to 0.6 ± 0.1 million years ago have been obtained by potassium-argon dating. Lava flows have been subdivided into the older Puente Group and the younger Tromen Group formations, which are of Pleistocene to Pleistocene-Holocene age, respectively; a Chapua Formation of Plio-Pleistocene age has been defined as well. The eastern volcanism is also known as the Pre-caldera basaltic unit; a western counterpart to it is probably buried beneath younger eruption products.

The first volcanic activity occurred west and east of Payún Matrú and involved the emission of olivine basalt lava flows. The long Pampas Onduladas lava flow was erupted 373,000 ± 10,000 years ago and buried parts of the 400,000 ± 100,000 years old Los Carrizales lava field; both have hawaiitic composition. The Payun volcano formed around 265,000 ± 5,000 years ago within a timespan of about 2,000–20,000 years. Its inferred eruption rate of 0.004 km3/kyr is similar to typical volcanic arc eruption rates such as at Mount St. Helens.

The main Payún Matrú massif formed in about 600,000 years, with the oldest trachytic rocks dated to 700,000 years ago. It is comprised by the lavic and ignimbritic Pre-caldera Trachyte unit and consists of trachyandesitic to trachytic rocks, with trachyte being the most important component. The massif may have formed a tall edifice like the Payun volcano before caldera collapse.

The formation of the caldera coincides with the eruption of the Portezuelo Ignimbrite/Portezuelo Formation and took place between 168,000 ± 4,000 and 82,000 ± 2,000 years ago. This ignimbrite formation where it is not buried by younger eruption products spreads radially around the caldera and reaches a maximum exposed thickness of 25 m; it covers an area of about 2200 km2 on the northern and southern sides of Payún Matrú, and its volume is estimated to be about 25 - 33 km3. The event was probably precipitated by the entry of mafic magma in the magma chamber and its incomplete mixing with pre-existent magma chamber melts, or by tectonic processes; the resulting Plinian eruption generated an eruption column, which collapsed, producing the ignimbrites. Different layers of magma in the magma chamber were erupted during the course of the eruption and eventually the summit of the volcano collapsed as well, forming the caldera; activity continued and emplaced lava domes and lava flows in the caldera area. These post-caldera volcanic formations are subdivided into three separate lithofacies.

Basaltic and trachyandesitic activity continued after the formation of the caldera. Morphology indicates that the El Rengo and Los Volcanes volcanic cones appear to be of Holocene age, while the Guadaloso vents formed during the Plio-Pleistocene. One age from the eastern side is 148,000 ± 9,000 years ago, it comes from northeast of the Payún Matrú caldera.

Uneroded volcanic cones and dark basaltic lavas indicate that activity continued into the Holocene. Large lava flows were erupted during the Holocene and covered extensive areas, burying the vegetation and impeding human settlement of the region until the late Holocene. Oral tradition by a local indigenous tribe indicate that volcanic activity occurred within the last several centuries, although no eruptions have been observed since the European settlement. Future volcanic eruptions would be unlikely to constitute a hazard given the low population density of the area, although roads might be interrupted and lava dams might form in rivers. It is considered Argentina's 24th most dangerous volcano out of 38.

Various dating methods have yielded various ages for late Pleistocene-Holocene volcanic eruptions:
 * 44,000 ± 2,000 years ago, surface exposure dating.
 * 43,000–41,000 ± 3,000 years ago, surface exposure dating, El Puente Formation. Basaltic lava flows of this formation reach ages of about 320,000 ± 5,000 years, implying a prolonged history of emplacement.
 * 41,000 ± 1,000 years ago, underlying the Los Morados lava flow.
 * 37,000 ± 3,000 years ago, surface exposure dating, close to the Rio Grande River.
 * 37,000 ± 1,000 years ago, La Planchada fallout deposit.
 * 37,000 ± 2,000 years ago, northwestern side of the caldera.
 * 28,000 ± 5,000 years ago, potassium-argon dating, lava flow on the westerly side.
 * 26,000 ± 5,000 years ago, potassium-argon dating, close to the Rio Grande.
 * 26,000 ± 2,000 years ago, potassium-argon dating, not the same as the 26,000 ± 5,000 flow.
 * 26,000 ± 1,000 years ago, potassium-argon dating, rhyolitic lava flow in the La Calle group.
 * 20,000 ± 7,000 years ago, north of the Payún Matrú caldera.
 * 16,000 ± 1,000 years ago, underlying the Los Morados lava flow.
 * 15,200 ± 900 years ago, potassium-argon dating, lava flow on the northwesterly-westerly side.
 * 9,000 years ago, potassium-argon dating.
 * 7,000 ± 1,000 years ago, potassium-argon dating, Escorial del Matru within the caldera.
 * <7,000 years ago, potassium-argon dating, trachyandesitic lava flow in the western part of the field.
 * 6,900 ± 650 years before present, thermoluminescence dating on the Guadalosos cones on an eastward running fracture.
 * 4,670 ± 450 years before present, thermoluminescence dating.
 * 3,700 ± 300 years before present, pumice fallout in and east of the caldera.
 * 3,400 ± 300 years before present, trachytic lava flows.
 * 2,000 ± 2,000 years ago, surface exposure dating, young looking lava flow in the west.
 * 1,705 ± 170 years before present, trachytic volcanic bombs.
 * 1,470 ± 120 years before present, thermoluminescence dating on Volcán Santa María although a much older age of 496,000 ± 110,000 years ago has also been given.
 * 515 ± 50 years before present, thermoluminescence dating on Morado Sur cone and on the Pampas Negras lapilli field.
 * 445 ± 50 years before present, lava domes on the caldera margin.

title: Payún Matrú


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Wikipedia:Featured picture candidates/Dhahran Hills

Dhahran Hills
Amazingly, this image was taken in Saudi Arabia, the image is in the Dhahran article and was taken by User:Eagleamn. - Eagle 14:25, Feb 12, 2005 (UTC)
 * Nominate and support. First vote here - Eagle 14:25, Feb 12, 2005 (UTC)
 * Oppose. There is nothing in this image to set it aside from any other small park-with-pond except the knowledge that this is in Saudi Arabia. For this to work, there should be a dune field in the background. Too much foreground grass does not help, nor does the blue (plastic?) along the waterline. Denni ☯ 21:19, 2005 Feb 12 (UTC)
 * Oppose -Most people alrady know that SA isn't a complete desert. Otherwise uninteresting photo.--Deglr6328 00:09, 13 Feb 2005 (UTC)
 * Oppose. Not striking informative, or otherwise FP material. Mgm|(talk) 09:29, Feb 14, 2005 (UTC)
 * Opppose. Enochlau 23:20, 17 Feb 2005 (UTC)]
 * Opppose It could be more interesting -- Longhair 08:59, 20 Feb 2005 (UTC)
 * Oppose. On its own, it's not FP-worthy. - Jpo 03:31, Feb 24, 2005 (UTC)
 * Not promoted +1/-6 BrokenSegue 18:29, 27 Feb 2005 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Wikipedia:Articles for deletion/British racing green

 This page is an archive of the discussion about the proposed deletion of the article below. This page is no longer live. Further comments should be made on the article's talk page rather than here so that this page is preserved as an historic record. The result of the debate was keep. -- AllyUnion (talk) 09:56, 21 Feb 2005 (UTC)

British racing green
Not really notable. Not sure how this could become a full blown Wikipedia entry. Perhaps belongs in Wiktionary? Jcsutton 14:27, 12 Feb 2005 (UTC)
 * Comment: I think it's notable, it gets 61,600 google hits and it's associated with a period in racing history. Could be expanded to include which teams used it and what success they achieved. No vote because it's just a dicdef right now. Kappa 18:28, 12 Feb 2005 (UTC)
 * Weak delete or Wiktionary. Of the first 10 hits, 8 are companies, colors, and/or websites named after the dic def, not a direct reference. Niteowlneils 20:08, 12 Feb 2005 (UTC)
 * Delete. Is this article about the British racing sailor Andy Green, or the test pilot Andy Green, or the color "British racing green" or what? Google this and see if you come away less confused than I was. hydnjo talk 23:47, 12 Feb 2005 (UTC) see below for vote change.
 * Keep and Expand. British racing green was a notable colour used by British racing car drivers and teams. For example, Jaguar in last year's F1 season. It was used as far back as the 1950's by drivers such as Stirling Moss. Needs to be expanded. If time permits, I'll have a go at it myself.Capitalistroadster 00:11, 13 Feb 2005 (UTC)
 * Keep - I recall hearing this color name before, and it has since been expanded into an acceptable stub. -- Cyrius|✎ 02:51, 13 Feb 2005 (UTC)
 * Keep. Clearly notable; the term will be easily recognized by any motorsport fan. — Dan | Talk 02:52, 13 Feb 2005 (UTC)
 * Keep, very much notable. James F. (talk) 02:52, 13 Feb 2005 (UTC)
 * Keep. Changing my vote because of content provided by 12.74.168.143 and thank you. hydnjo talk 03:12, 13 Feb 2005 (UTC)

 * Now that it is expanded, I agree that there is sufficient for a Wikipedia article. Will delist from VFD unless there are any other strong objections. Jcsutton 11:55, 13 Feb 2005 (UTC)
 * Strong Keep - my favourite colour ! Brookie 19:50, 13 Feb 2005 (UTC)
 * Strong Keep after the cleanup into a good stub indicating the color's origins and significance. BRG is the single most "historically significant" color in the history of motorsports.  The only color that has similar power to inspire emotion in millions of fans is Petty blue.  (But there are tens of thousands of fans of pavement modifieds on eastern USA ovals who feel the same way about Richie Evans orange.  Evans orange matches the paint code used by the New York State DMV in the mid-1960s when he was getting started on a near-zero budget.)  Barno 00:39, 14 Feb 2005 (UTC)
 * Clear keep (and expand) -- Jmabel | Talk 06:39, Feb 14, 2005 (UTC)
 * Keep max rspct 19:00, 16 Feb 2005 (UTC)
 * Keep - notable. Hazzamon 17:55, Feb 17, 2005 (UTC)
 * Keep - my favourite colour. Couldn't see the vfd tag on the article page Brookie 19:14, 17 Feb 2005 (UTC)

This page is now preserved as an archive of the debate and, like some other VfD subpages, is no longer 'live'. Subsequent comments on the issue, the deletion, or the decision-making process should be placed on the relevant 'live' pages. Please do not edit this page.


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Talk:Unlawful combatant/Archive 2

Informative, but difficult to understand in places:
 * What does this mean: "the president personally, after consulting with Secretary of Defense Rumsfeld, White House Press Secretary Scott McClellan, and Senior Adviser Karl Rove, decided to go for a walk"?
 * What does this mean: "The nation wondered what would happen, with seemingly no law established in this area, but for the administration's actions."
 * What does this mean: "At this point there were these two most famous enemy combatants, and the 600+ in Cuba not going anywhere in our legal or military system."
 * Is "president" capitalized or not?

Accuracy note
This is nothing against your re-write Viajero, (some of it is arguably a little POV like "hawkish," but on the whole it is good) but I do think there is much more pertinent information missing and until the article and the format is "settled" I think this should be at the top of the page to let readers know there is far more to it than what is written (if there is a better tag than "accuracy", feel free to change it). For example: "arrested or captured in armed combat," is that really the case? Is there even an enemy combatant law or is it just a concept? If there is, we need to use that for a source. Also, who decides who is an enemy combatant (I'm fairly sure it's an executive order, but I haven't scoured for a source on that)? Why don't the Geneva Conventions apply to at least Afghanistan,is it because war has to be officially declared or some other reason? etc.

Do you agree or do you think it's accurate enough as it is? I just don't think there is enough information here for readers to get an accurate overview of the concept.—Ben 18:05, 24 Feb 2005 (UTC)

and had I thought of it earlier, I would have put the accuracy note before you had even re-written, it's just that you left out the part about executive decision, and I think that's very important... if it's true. But I can't put it in if it isn't! :P --Ben 18:10, 24 Feb 2005 (UTC)

 * Hi Ben, you raised a number of problematic issues. First and foremost, the concept of illegal enemy combatant has never been legislated or formally defined anywhere. No, there is no such law. Geneva only deals with two categories: civilians or military personnel. It is something that Bush's advisors have come up with so as to avoid having to go through the normal channels and be able to expedite the "war on terror". I don't think there is a single executive order for it; it is applied on an ad hoc basis. As to why the Geneva Conventions don't apply to Afghanistan, this is because the White House decided that the country was a "failed state" and Conventions weren't applicable to its citizens. Yes, this is all very problematic, and its status is very unclear under international law. This is indeed exactly why it is so controversial; it potentially jeopardizes the civil rights of both Americans and non-Americans because of the absence of due process. If you are interested in this subject, I recommend you read this long but very interesting article by Jane Mayer: "OUTSOURCING TORTURE: The secret history of America’s 'extraordinary rendition' program" (It appeared in last week's New Yorker and I used it as a source for this article. As to the word "hawkish", if you substitute "pro-war" it means the same thing, and I don't think it is controversial to indicate that many individuals in the Bush adminstration are "pro-war"; this is well documented. In closing, I am not thrilled about the "accuracy disputed" message; it may be incomplete but it is not inaccurate (but I will not remove the tag). Lots of WP articles are incomplete; this is no sin. All the best, -- Viajero 19:02, 24 Feb 2005 (UTC)

 * The main thing I'm worried about is inaccurately framing the term. I think that the article should have enough facts that the reader is able to determine the legitimacy and legality on their own and from their own perspective. From what I personally know, and from my personal perspective, it is entirely illegitimate, it seems to me that Bush can just say "this citizen is an enemy combatant" and then spirit them away to Guatanomo without trial or lawyer. I just want to know if my views are based on the reality of the situation or if my view is based on an oversimplification. Maybe there are checks and balances as to who is determined an enemy combatant (not that that would necessarily make me agree with imposing this political concept). It's just such a nebulous term (something I think is an entirely purposeful way of defining it, but that's besides the point) that it suggests certain contexts which may or may not be true or accurate. Is it fair to compare people deemed "enemy combatants" to "prisoners of war?" if so, then what war? The "war on terror?" Can that be said to be a war, and if so, can it be said that all terrorists are engaged in "war?" and that for example, say Britain, can deem random Irish guys in Britain "enemy combatants?" There are just so many questions and I think it is better to actually avoid trying to answer those questions and wrangle with them by writing the most accurate article from the most objective and neutral point of view. I mean, Jose Padilla was not "arrested or captured in armed combat" unless you believe all terrorists are engaged in armed combat, that combat being the "war on terror," which is a concept defined by the Bush administration. He was, as far as I know, simply a person "planning to blow up a building for a political reason" and therefore, a terrorist. --Ben 17:25, 1 Mar 2005 (UTC)

 * First, I need to apologize: I left a rather terse note on your Talk page. I didn't realize that Ben == Benapgar. My mistake.
 * Second, you were parsing the phrase "arrested or captured in armed combat" in a way which I hadn't intended. I have changed it to: "captured in armed combat or arrested". In this way it accounts for cases like Padilla.
 * For the rest, I am having difficulty distinguishing between your discomfort with the concept "illegal enemy combatant" (shared by all fair-minded souls I would hope) and the article has it now stands. What is lacking? How can we improve it?
 * All the best. -- Viajero 19:14, 1 Mar 2005 (UTC)

 * First off, I think not relying on comparison to present the concept is the best way. Information relating to the Geneva Conventions should probably be in its own section (i.e. how the concept circumnavigates the conventions) and comparison and contrast to prisoners of war and unlawful combatants should be in their own section. The history of the term (how it came about) and examples of the use should both have their own sections as well. The way it's written now is like it is "the history of the term 'Enemy Combatant'" which, while relevant, doesn't get the concept across in a straightforward way. We must have a legal definition, even if that definition is "there is no legal definition of an enemy combatant." Note also that if there is no legal definition as you claim, the modifier "illegal" in the title is incorrect then, right?

What I'd like to see (in no particular order) is:

 * How people are labelled this way (the legal definition or who makes the decision to label people)
 * The result of being labelled this way (what happens if you are labelled this way)
 * The conceptual framework which is used to label people this way. (who is an enemy combatant, why are they enemy combatants)
 * History/development of the concept (Gonzales etc.)
 * Criticisms of the concept (legal criticism etc.)
 * Comparison/contrast to similar concepts (Geneva conventions, prisoners of war, unlawful combatants, etc.)

This isn't a perfect way to describe it, but I think it would be a good start. Not all of this stuff is necessarliy known (for example, if the President can declare anyone an enemy combatant, why a President would do so is irrelevant in a legal and governmental context as it does not guarantee reasons of future Presidents)--Ben 18:51, 7 Mar 2005 (UTC)

Enemy combatant
I think the redirect from "enemy combatant" to "Illegal enemy combatant" is not correct. Surely an enemy combatant is a combatant fighting for the other side in an armed conflict? So in the Falklands War enemy combatants were for the British members of the Argentinian armed forces. It should be redirected to combatant Philip Baird Shearer 17:31, 9 Mar 2005 (UTC)

I've moved all the the links to that page to either "illegal combatant" or "illegal enemy combatant". I have then redirected it to "combatant" Philip Baird Shearer 16:53, 10 Mar 2005 (UTC)

Unlawful combatant
What is the diffrence between "Illegal enemy combatant" and Unlawful combatant? Philip Baird Shearer 17:31, 9 Mar 2005 (UTC)

Merge with Unlawful combatant section United States
It seems to me that if this page is going to become a useful article it will have to start to duplicate the "Unlawful combatant" page. So it makes to merge them on the lines specified in Duplicate articles. This page should then become a redirect to the "Unlawful combatant" page. I have already edited the Unlawful combatant page so that there is a clear section for the USA and any additional material from this article should be placed there. I am going to leave the banner in place for a couple of days before I start to move anything so that the original authors have a chance to move what they think is relevent before I have a go at it.

I have added the template:merging to this article which has produced the following at the top of the article:
 * This article is in the process of being merged into Unlawful combatant, and may be outdated. If necessary, please only edit the page shown above, as this page's content may be deleted in the future.

--Philip Baird Shearer 15:56, 15 Mar 2005 (UTC)

 * But "Unlawful Combatant" has an entirely different legal meaning than the American "Illegal Enemy combatant." They are similar, but "unlawful" refers to International Law and the Geneva Conventions. "Illegal Enemy combatant" refers to American law. They are seperate legal issues and should be dealt with separately. Illegal Enemy Combatants are not Unlawful Combatants. If you don't agree, you can simply deduce this from the fact that "Illegal Enemy Combatants" are not afforded any rights under the Geneva Conventions because they are not in the Geneva Conventions in the first place. People deemed "Illegal Enemy Combatants," as far as I know, gain no rights from International law, and therefore are not "Unlawful Combatants" under that law.

 * The problem with generalizing the term Unlawful Combatants to include "Illegal Enemy Combatant" is that this raises the issue of "what is combat?" and "what is it illegal to do in combat?" which the Geneva Conventions long ago sorted out for the most part. Throwing out their definition to create our own based on a POV definition, not a legal one, of "combat" and "unlawful" will cause all sorts of POV problems in the article. I'll be the one causing them too, so you probably don't want to start that. (I'll say things like "I do not consider terrorism combat" or "what makes this illegal." I even think this article should not have the word "Illegal" in it, since apparently you don't have to even commit a crime to be hauled off to Guatanamo.)--Ben 00:40, 16 Mar 2005 (UTC)

The "unlawful combatant" article used to be called "illegal combatant" and was changed because of the "ex parte Quirin" case, that was the only Supreme Court reference in the US was "unlawful combatant" at the time the change took place. If you look at President Issues Military Order Detention, Treatment, and Trial of Certain Non-Citizens in the War Against Terrorism, it does not use the phrase "illegal enemy combatant", the phrase seems to be a shorthand used by the US administration and does not have a precise legal definiton, this is something that the US courts are sorting out.

The word "enemy" is not realy relevant here because it is implied in "unlawful (enemy) combatant". Usually what happens if it is an illegal friendly combatant is arrested by their own side they are tried under their own military code of justice and do not have any protection under GC because they are not POWs.

The problem with the Quin case was that it took place before the current Geneva Conventions (GC) were written, so the GC are not fully incoporated into US domestic law. As the current cases grind their way through the US domestic system this is starting to happen eg (from the unlawful combatant article):
 * On November 8, 2004, a federal court halted the proceeding of Salim Ahmed Hamdan, 34, of Yemen. Hamdan was to be the first Guantanamo detainee tried before a military commission. Judge James Robertson of the U.S. District Court for the District of Columbia ruled that no competent tribunal had found that Hamdan was not a prisoner of war under the Geneva Conventions.

Without the surrounding information which the unlawful article contains about GC and other information I would agree with you that it is not possible to write a balanced article. But with that in place it should be possible to do so for the current US position which the US courts are slowly bringing into line with international law.

BTW It is not highlighted in the UC article but many of the combatants incarcerated by the Americans have no protection under GCIV. This is because,(once they are found to be illegal combatants by a competent tribunal (under GCIII)), most of them are Nationals of a state that has normal diplomatic representation in the State [USA] in whose hands they are . Philip Baird Shearer 09:42, 16 Mar 2005 (UTC)

THIS IS AN ARCHIVE ADD ANY NEW COMMENTS TO Talk:Unlawful combatant Philip Baird Shearer 13:06, 17 Mar 2005 (UTC)

title: Talk:Unlawful combatant/Archive 2


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Ashikaga Tadayoshi

Ashikaga Tadayoshi (足利 直義) was a general of the Northern and Southern Courts period (1337–92) of Japanese history and a close associate of his elder brother Takauji, the first Muromachi shōgun. Son of Ashikaga Sadauji and Uesugi Kiyoko, daughter of Uesugi Yorishige, the same mother as Takauji, he was a pivotal figure of the chaotic transition period between the Kamakura and Muromachi shogunates. Tadayoshi is today considered a military and administrative genius and the true architect of many of his elder brother's successes. In contemporary chronicles he is rarely called with his name, but is instead called either gosho (御所) or Daikyū-ji-dono (大休寺殿) from the name of his family temple. His posthumous name was Kozan Egen (古山慧源).

Biography
The Ashikaga were a samurai family from Kamakura having blood ties with the Seiwa Genji, Minamoto no Yoritomo's clan. Unlike his brother Takauji, Tadayoshi took no part in the Kamakura shogunate's political activities until the Genkō War (1331–1333), a civil war whose conclusion (the Siege of Kamakura (1333)) marks the end of the Kamakura period and the beginning of the most turbulent period in Japan's history, the Muromachi era.

Like his brother, Tadayoshi resolutely abandoned the Kamakura shogunate (de facto ruled by Hōjō clan) to ally himself with formerly expelled Emperor Go-Daigo during the Kenmu Restoration of 1333. When Go-Daigo had ascended to the throne in 1318, he had immediately manifested his intention to rule without interference from the military in Kamakura. The samurai class as a whole however was not ready to give away power, so the alliance between him and the Ashikaga was bound to be only temporary.

Go-Daigo wanted to re-establish his rule in Kamakura and the east of the country without sending there a shōgun, as this was seen, just a year from the fall of its shogunate, as still too dangerous. As a compromise, he sent his six-year-old son Prince Norinaga to Mutsu Province and nominated him Governor-General of the Mutsu and Dewa Provinces. In an obvious reply to this move, Tadayoshi, without an order from the Emperor escorted another of his sons, eleven-year-old Prince Nariyoshi (a.k.a. Narinaga) to Kamakura, where he installed him as governor of the Kōzuke Province with himself as a deputy and de facto ruler. The appointment of a warrior to such an important post was intended to demonstrate the Emperor that the samurai class was not ready for a purely civilian rule. Since he ruled without interference from Kyoto and the area in itself was in effect a miniature shogunate, this event can be considered the beginning of the Ashikaga shogunate.

In 1335, during the Nakasendai Rebellion led by Hōjō Tokiyuki Tadayoshi, being unable to defend the city, had to leave Kamakura in a rush. Not being in the position to take along another son of Go-Daigo's, Prince Morinaga, whom he had kept as a hostage for several months, rather than letting him go he decided to have him beheaded.

In Dec. 1335, Tadayoshi was defeated by imperial forces under the command of Nitta Yoshisada forcing his retreat to the Hakone mountains. However, with the aid of his brother Takauji, they were able to defeat Yoshisada at the battles of Sanoyama and Mishima. The brothers were then free to advance upon Kyoto.

Their occupation of Kyoto was short lived however, as forces loyal to Go-Daigo forced the brothers to flee west. In April 1336, Ashikaga Tadayoshi, "drove the enemy before him" helping his brother defeat the Kikuchi clan, allies of Go-Daigo. This Battle of Tatarahama (1336) occurred in Hakata Bay. The victory enabled Takauji to become master of Kyushu.

By May, Takauji was able to advance with a flotilla, reaching the environs of present-day Kobe in July. Tadayoshi followed in parallel with a land force.

Turning against Go-Daigo, Tadayoshi and Takauji set up a rival emperor in 1336 after defeating the Loyalists in the Battle of Minatogawa. Their Muromachi shogunate was founded in 1338.

Dividing power between them, Takauji took charge of military affairs and Tadayoshi of judicial and administrative matters.

Both Tadayoshi and Takauji were disciples of famous Zen master, intellectual and garden designer Musō Soseki, under which guidance the first would later become a Buddhist monk. It was partly because of Soseki's influence that the pre-existing Five Mountain System network of Zen temples was expanded and strengthened, first with the establishment of the Jissetsu, and later with that of the Ankoku-ji temple sub-networks. The creation of both systems is generally attributed wholly to Tadayoshi. It was also Soseki which famously wrote about the two brothers, describing Takauji as more apt to military pursuits, and Tadayoshi to government.

The Kannō disturbance and Tadayoshi's death
Ashikaga Takauji was the formally-appointed shogun but, having proved incapable of ruling the country (namely, Northern Court), for more than ten years Tadayoshi had governed in his stead. The relationship between the two brothers was however destined to be destroyed by the Kannō disturbance, an event which takes its name from the Kannō era (1350–1351) during which it took place, and which had very serious consequences for the entire country. Trouble between the two started when Takauji made Kō no Moronao his deputy shōgun. According to the Taiheiki, Tadayoshi didn't like Moronao and, every other effort to get rid of him having failed, tried to have him assassinated. According to the same source, his plot was discovered and he was therefore removed from the government. In any event, Tadayoshi in 1350 was forced by Moronao to leave the government, and take the tonsure under the monastic name Keishin.

In 1351 Tadayoshi rebelled and joined his brother's enemies, the Southern court, whose then emperor, Go-Murakami appointed him general of all his troops. In 1351 he defeated Takauji, occupied Kyoto, and entered Kamakura. During the same year his forces killed Moronao and his brother Moroyasu at Mikage (Settsu Province). The following year Tadayoshi's fortunes turned and he was defeated by Takauji at Sattayama. A reconciliation between the brothers proved to be brief; Tadayoshi was sandwiched by two of Takauji's armies and fled to the hills of Izu in 1352. Shortly after an ostensible second reconciliation, Tadayoshi was captured and confined in the Kamakura Jomyoji monastery, where he died suddenly in March. According to the Taiheiki, by poisoning.

Ashikaga Tadayoshi was buried at Kumano Daikyū-ji (熊野大休寺), a Buddhist temple which no longer exists, but whose ruins are now near Jōmyō-ji in Kamakura. The temple was founded on the grounds of Tadayoshi's former Kamakura residence, according to Jōmyō-ji's own records by Tadayoshi himself. According to the Kuge Nikkushū (空華日工集), the diary of priest Gidō Shūshin, in 1372 on the day of Tadayoshi's death Kamakura's Kubō Ashikaga Ujimitsu visited Daikyū-ji. The date of disappearance of the temple is unknown. He also adopted Ashikaga Tadafuyu, one of Takauji's biological sons, as his own.

Family

 * Father: Ashikaga Sadauji (1273–1331)
 * Mother: Uesugi Kiyoko (1270–1343)
 * Wife: Shibukawa Yoriko later Honkoin
 * Son: Ashikaga Nishimaru (1347–1351)
 * Adopted son: Ashikaga Tadafuyu (1327–1387)

title: Ashikaga Tadayoshi


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Layne Morris

Layne Morris (born 1962) is a retired American special forces operative. On July 27, 2002, he was wounded and blinded in one eye during a gunfight in Afghanistan that left American combat medic Christopher J. Speer dead, allegedly at the hands of the Canadian accused terrorist Omar Khadr.

"'A piece of the hand grenade shrapnel cut the optic nerve, so I'm blind in one eye.'"

Khadr, a Canadian child soldier of Egyptian and Palestinian descent, was captured by American troops at Ayub Kheyl shortly after the gunfight; he was alleged to have thrown the grenade that had killed Speer and wounded Morris, and was subsequently detained at Bagram Airfield. By late 2002, he was transferred to the Guantanamo Bay detention camp, where he eventually pled guilty to killing Speer. Khadr's lawyers allege that he was tortured into confessing. In 2012, Khadr was released from American custody and handed over to the Canadian government. Morris, along with Speer's widow, filed a civil suit against Khadr's father, who allegedly had close ties with al-Qaeda. Their claim held Khadr's father responsible for Khadr's actions, as the latter was a legal minor — aged 15 at the time of the incident.

Morris retired from the military. He returned to his home in Utah, where he became a housing director in West Valley City. He lives with his wife Leisl in South Jordan, a suburb of Salt Lake City. He appeared in the National Geographic Society program U.S. Army Special Forces in 2003 and also interviewed on 60 Minutes in 2007.

Civil suit against Omar Khadr's family
The American government alleged that Khadr's Egyptian father Ahmed Khadr had been a close associate of Osama bin Laden and actively worked with members of al-Qaeda. In 2004, Ahmed was killed by Pakistani security forces in a gunfight near the Afghanistan–Pakistan border. Morris joined with Speer's widow Tabitha to file a civil suit against Ahmed's estate. His argument, then, was that since Omar was only 15, he could not be held responsible for his actions — but his father could.

Normally, "acts of war" are not subject to civil suits. However, Morris and Speer successfully argued that Khadr was a terrorist and not a soldier, so his actions were not exempted from civil suits.

"'The family was all in Pakistan, I thought, all right, you made your choice, fine, have a nice life and I was okay with it. It was when they pulled out the Canadian passports and started waving them around to come back and take advantage of their free everything because it hadn't gone well for them – that was the point when I said, you know there's something additionally I can do.'"

On February 16, 2006, American district judge Paul G. Cassell awarded Morris and Tabitha triple damages, totalling US$102.6 million. An article published in the June 14, 2007, The Salt Lake Tribune said that Morris and Tabitha might collect funds via the U.S. Terrorism Risk Insurance Act. An official from the U.S. Treasury Department had acknowledged that Ahmed's assets had been frozen, but said it was up to Morris and Speer to locate them. American senator Orrin Hatch had been asked to intervene and was "very interested" in the case.

In January 2008, an American attorney claimed that the federal government had "sovereign immunity" over the seized funds, asserting that it did not have to comply with a judgement in a civil suit:

"'Although sovereign immunity may be waived, there is no waiver in this case.'"

Guantanamo military commissions
Omar Khadr was named as one of ten detainees who faced charges before special military commissions. These commissions were not courts-martial.

Guantanamo military commission chief prosecutor Morris D. Davis said, on January 10, 2006, that he planned to call Morris as a witness against Khadr; Morris was to testify that he knew he was injured by Khadr. On June 29, 2006, the U.S. Supreme Court upheld an earlier ruling that the commissions were unconstitutional because they had not been authorized by the U.S. Congress, and violated both the Uniform Code of Military Justice and the United States' obligations under the Geneva Conventions.

Morris told interviewers he was disappointed that the military commissions had been overturned:
 * "It is justice delayed. I don't think that's a good thing ... I think those tribunals could have provided a trial viewed as fair by most of the world. In that sense, I think it is unfortunate,"
 * "I guess I don't agree with giving these people all of the legal rights that citizens have,"
 * "I think everyone on both sides of the political aisle just wants to see some sort of resolution to their status and I guess it's just going to take longer now to figure out how that process is going to work."

In 2008, a five-page statement from an American soldier who shot Khadr said that the youth had not been the only occupant of the compound to have survived the American aerial bombardment. He said further that Khadr had been shot in the back; he was sitting upright with his back to the skirmish. This cast doubt on assertions that Khadr had thrown the grenade that killed Speer.

In a telephone interview with Michelle Shephard of the Toronto Star, Morris insisted: "That was a total shock to me. Everyone had told me from the get-go that there was only one guy in there." He thought there was evidence that "Omar was the grenade man."
 * "Instead of surrendering and calling it a day, he made the decision to wait until personnel got close enough that he could restart the battle, pop up and throw a hand grenade."
 * "I'm fine with this dragging on for another five years before there's a trial as long as they stay locked up."

Canada's settlement with the Khadr family
Morris criticized the Canadian government for paying out CA$10.5M to Khadr, describing it as “outrageous” in a letter. He called for Canadian prime minister Justin Trudeau to be charged with treason, accusing him of being a "groupie" and "supporter" of Omar Khadr. He asserted that "it was wrong" for the Canadian government to settle Khadr's lawsuit, and that it should have been taken to court instead.

title: Layne Morris


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Peinado

Peinado is a stratovolcano in Catamarca Province, Argentina. It consists of a volcanic cone with a summit crater, surrounded at its foot by lava flows erupted from flank vents. It began erupting about 100,000 years ago, with the last eruption about 36,800 years ago. Future eruptions are possible.

The volcano is part of the Andean Central Volcanic Zone and located within a cluster of calderas and large volcanoes, including the Laguna Amarga caldera just west of Peinado. The climate of the region is cold and dry, but may have been moister in the recent past. North of Peinado lies the salt lake Laguna Peinado.

Geography and geomorphology
Peinado lies in Argentina's Catamarca Province, close to the border with Chile and about 30 km from the Paso San Francisco. Geographically, it is in the Cordillera Occidental of the Central Andes. The region is largely uninhabited, due to the extreme climatic conditions.

The volcano is a c. 1630 m high steep cone, which reaches an elevation of 5890 m above sea level and features a 240 m wide and 25 m deep summit crater with an ephemeral crater lake. There is no perennial snow cover or glaciers on the mountain. Twelve vents - two of which are buried by lava flows - form cones on its flanks and have produced hundreds of lava flows, which built a lava apron surrounding the volcano that buries the lower parts of the cone. The cone is formed by lava blocks, lavas, pyroclastics and scoria; the lava flows have for the most part dark and brown colours. The total volume of the edifice is about 22.4 km3, covering an area of 96.2 km2. Claims that the volcano overlies a caldera lack supporting evidence.

Just west of Peinado lies the eastern margin of the Pliocene Laguna Amarga caldera; its ignimbrites underlie Peinado and lava flows from Peinado have spilled across its borders on to the caldera floor. On the eastern side, the volcano is bordered by the Sierra de Calalaste. To the north lies the Salar de Antofalla, which ends close to Peinado, and the Laguna Peinado lake. A field of monogenetic volcanoes, the Peinado volcanic field, lies around Peinado. They consist of lava flows, maars, scoria cones and tuff rings, with volumes reaching 0.8 km3, and were emplaced between 600,000 and 150,000 years ago.

Lake
Laguna Peinado is a 1.2 km wide, 3.4 km long lake with a mean depth of 4 m-8 m. Water covers an area of 1.6 km2. It lies at 3820 m elevation at about -26.49972°N, -68.09222°W. It is a salt lake with alkaline waters, fed mostly by groundwater and meltwater. An additional water source are hot springs with temperatures reaching 33.13 C, which deposit travertine. Volcanic carbon dioxide outgassing appears to occur at the lake. The lake presently has no outflow, but it may have spilled northward into the Salar de Antofalla during periods of higher lake level. Directly north of Laguna Peinado lies another lake, Laguna Turquesa, with an average depth of 6 m and a surface area of 0.1 km2; the lakes may have been connected before 2005. At the northern end of the basin, coastal terraces reach thicknesses of 30 - 40 cm and lengths of several 100 m, they extend to Laguna Turquesa. At the southern end of the lake is a wetland.

Lake sediments consist of an alternation of organic muds, calcite and travertine, with limestones occurring in coastal areas and muddy deposits in deeper waters. The carbonates form micrites, packstones, rudstones and wackestones, and they contain fossil diatoms and ostracods. Microbes form rocky structures including mounds and oncolites.

There is evidence of a progressive increase in water levels, followed by a decrease, which may somehow relate to the Little Ice Age. They may be correlative with regional changes in humidity, but difficulties in dating lake deposits prevent the determination of a definitive causal relationship.

The lakes of the Altiplano have drawn attention in the 21st century owing to the frequently extreme climatic and hydrological conditions they experience. Microbialites form mounds along 2 km of the western lakeshore. Former stromatolites occur on the lowest lake terrace, they display laminated textures and were probably built by cyanobacteria when the lake levels were low and conditions more favourable to stromatolite growth than plant development. Recent lake level declines have not prevented the deposition of microbe-produced rocks. Stromatolites are visible just underneath the water surface.

Geology
Peinado is part of the Central Volcanic Zone of the Andes, which in northern Argentina extends across the Cordillera Occidental and the Altiplano. Numerous volcanoes occur in the region, including Laguna Amarga, Sierra Nevada de Lagunas Bravas, Laguna Escondida, Cerro El Condor, Wheelwright caldera, Falso Azufre, Nevado Tres Cruces, Ojos del Salado, Incahuasi, Cerro Torta, Cerro Blanco, Cueros de Purulla and numerous other calderas with accompanying ignimbrites, and monogenetic volcanoes. Their ages range from Miocene to Quaternary; volcanism there has been ongoing since the Eocene-Oligocene. Peinado presumably developed on Miocene volcanic rocks and eruption products of the Laguna Amarga caldera. A major strike-slip fault zone, the Peinado fault, runs from the western side of Salar de Antofalla south along Laguna Peinado to Peinado volcano. Farther south, it may connect to the San Francisco lineament. Apart from volcanoes, tectonically-generated basins and ridges form a steep relief in the region; the Laguna Peinado occupies one of several north-south trending tectonic depressions in the area. Magma may be present in the crust.

Volcanic rocks are mainly andesite and basaltic andesite, with dacite being erupted more recently. They define a potassium-rich calc-alkaline suite and contain phenocrysts of clinopyroxene, iron-titanium oxides, olivine, orthopyroxene and plagioclase. As is common for stratovolcanoes, the more felsic magmas were erupted from the central cone and the more mafic ones from the flank vents. The monogenetic volcanoes have erupted basaltic andesite. In the summit region, the rocks have been discoloured presumably by hydrothermal alteration.

Eruption history
Peinado is one of the youngest volcanoes in the area. Radiometric dating has yielded ages ranging between 80,000 and 40,000 years ago for the central cone and between 60,000 and 30,000 for the flank vents. Volcanic activity initially built the central cone, before continuing on the flanks. Eruptions have been mostly effusive, but with recent explosive events. The monogenetic volcanoes just south and north of Peinado developed 210,000 ± 40,000 and 380,000 ± 20,000 years ago, respectively; the flank vent that formed a scoria cone may also be associated with the monogenetic activity rather than Peinado proper.

Presumably, Peinado began its growth as a monogenetic volcano but eruptions became concentrated at a single vent, producing a shallow magma chamber that intercepted ascending magma and a single cone. Eventually, the cone reached a size at which further eruptions from the summit were impeded, causing volcanism to shift to the flank vents, which then built up the bulk of Peinado. Fractional crystallization and other magma-forming processes took place in the magma chamber, yielding the felsic magmas that were erupted from the central vent beginning 40,000 years ago.

There are reports of fumarolic activity. Volcanoes have been observed to remain inactive for ten thousands of years; thus future activity at Peinado is possible. The configuration of volcanic vents suggests that the occurrence of caldera collapse and of sector collapses is possible, and its activity has become more explosive over time. The volcano lies on an eastward younging trend of calderas including Laguna Amarga, and there is evidence of magma storage in the crust.

Climate and vegetation
The regional climate is cold and dry, with a mean temperature of 8 C and large (40 C-change) daily temperature fluctuations. Precipitation takes place mainly during the winter months, the region is at the boundary between the South American Summer Monsoon region and the westerlies region, where precipitation occurs when cold fronts from the Pacific Ocean and isolated drops of cold air hit the area. Evaporation rates are higher than precipitation. The climate has not been stable during the Pleistocene, and may have been wetter during glacial times. What little vegetation there is, is mostly steppe grasses. Salt-loving vegetation and underwater plants grow around and in Laguna Peinado, which also features microbial mats.

Name and human activity
The name ("combed" in Spanish) is a reference to its smooth appearance. The first known ascent was by in 1965, but the mountain features a pre-Hispanic mountain sanctuary and may have been used as a source for valuable rocks by pre-Hispanic people. A prehistoric copper and aragonite mine with well-preserved buildings lies at Tambería El Peinado, close to the volcano.

title: Peinado