Muthuvairavasamy Ramkumar
email: muramkumar@yahoo.co.in

David Menier

Manoj Mathew

M Santosh

Numair A Siddiqui

Early Cenozoic rapid flight enigma of the Indian subcontinent resolved: Roles of topographic top loading and subcrustal erosion Q 5

Keywords:

Intrinsic magmatic processes are considered as critical operators of plate movements. Here we demonstrate the role of extrinsic processes consequent to intrinsic processes as a catalyst for anomalous rapid plate movement. The rapid and accelerated flight of the Indian subcontinent since Deccan volcanism until its collision with Eurasia remains as one of the geological conundrums. Data on seismic tomography, peninsular geomorphology and inferences on continuum of subcrustal structures are utilized to address this enigma. We propose geomorphic isostasy as the mechanism that has driven this fastest drift ever recorded in geological history. It was initiated by sudden instability after the Deccan volcanism and resultant extensive accumulation of lava pile over continental lithosphere of northern India, northern-eastern tilt due to crustal thickness heterogeneity and subcrustal thermal stratification. The drift was sustained by Carlsberg and Central Indian ridge-push until collision and sediment top loading at northeast thenceforth. These inferences and geomorphic isostasy as a catalytic mechanism necessitate variability of drift rates as integral inputs for any continental scale modeling.

Introduction

Driven by deep convection currents, continental plates drift over the plastic asthenosphere at rates of few centimeters per year [START_REF] Jagoutz | Anomalously fast convergence of India and Eurasia caused to double subduction[END_REF]. Large scale plate reorganization plays first order controls on orogeny, changes in ocean-basin volume, basin evolution, climate and sea level and enforce topographic feedback as a continuum [START_REF] Campanile | Sedimentation record in the KonkaneKerala Basin: implications for the evolution of the Western Ghats and the Western Indian passive margin[END_REF]. Plate reconstruction theories and models of rifts/drifts often take into account intrinsic magmatic processes as the critical operator of continental drifts [START_REF] Cande | Indian and African plate motions driven by the push force of the Réunion plume head[END_REF][START_REF] Müller | Plate motion and mantle plumes[END_REF][START_REF] Van Hinsbergen | Acceleration and deceleration of India-Asia convergence since the cretaceous: roles of mantle plumes[END_REF][START_REF] Koptev | Dual continental rift systems generated by plumeelithosphere interaction[END_REF]. And more frequently overlook the inherent nature of these events that always work on differential rates and at highly discontinuous periodicity [START_REF] Müller | Plate motion and mantle plumes[END_REF]. The resultant surficial disequilibrium operates under the influences of a variety of factors and responds in distinct spatio-temporal scales. Little is known how rapid plate reorganization events that continue for long geological timescales can be highly varied, persistent and produce topographic feedbacks.

The tectono-geomorphic evolution of the Indian subcontinent commenced at w167 Ma following the breakup of Gondwana supercontinent. The subsequent drift represents exceptional journeys (w9000 km) of all the continents involving plate tectonic and landform diversification events [START_REF] Chatterjee | The longest voyage: tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia[END_REF]. Soon after the basaltic eruption at the end of Cretaceous, India drifted northward at about 20 cm/yr; a rate exceptionally high [START_REF] Chatterjee | The longest voyage: tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia[END_REF] as compared to present-day rate of w5 cm/yr. The driver of this early-Cenozoic acceleration still remains enigmatic.

Here we demonstrate the interplay between intrinsic and extrinsic sources as catalysts of anomalous rapid plate reorganization. Based on isostatic compensation, denudation and recurrent reactivation GSF454_proof ■ 3 June 2016 ■ 1/9

Please cite this article in press as: Ramkumar, M., et al., Early Cenozoic rapid flight enigma of the Indian subcontinent resolved: Roles of topographic top loading and subcrustal erosion, Geoscience Frontiers (2016), http://dx.doi.org/10.1016/j.gsf.2016.05.004 of ProterozoiceCretaceous tectonic structures, and subcrustal dynamism, we establish geomorphic isostasy as the mechanism that initiated the faster drift of the Indian subcontinent in the aftermath of Deccan volcanism.

Geological setting

The Indian subcontinent is an assemblage of microcontinents that experienced extensive volcanism, plutonism, metamorphism, and sedimentation preserving structures (Fig. 1) inherited since early Proterozoic [START_REF] Chatterjee | The longest voyage: tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia[END_REF][START_REF] Collins | Peninsular India in Gondwana: the tectonothermal evolution of the Southern Granulite Terrain and its Gondwanan counterparts[END_REF]. A continuum of structural and resultant geological-geomorphic evolution of the Indian subcontinent is evident from the occurrences and/or alignments of Paleozoic, Mesozoic and Cenozoic sedimentary basins [START_REF] Banerji | Post-eocene biofacies, palaeoenvironments and palaeogeography of the Bengal Basin, India[END_REF] and escarpments, and plateaus (Fig. 1) essentially along older faults/suture zones [START_REF] Jayalakshmi | Late pleistocene-holocene paleoclimatic history of the Southern Kerala Basin, Southwest India[END_REF][START_REF] Biswas | A review of structure and tectonics of Kutch basin, western India, with special reference to earthquakes[END_REF][START_REF] Mishra | Evidence for Proterozoic collision from airborne magnetic and gravity studies in Southern Granulite Terrain, India and signatures of recent tectonic activity in the Palghat Gap[END_REF][START_REF] Ramkumar | Geological, geophysical and inherited tectonic imprints on the climate and contrasting coastal geomorphology of the Indian Peninsula[END_REF]. Occurrences of Permo-Triassic and early Cretaceous deposits only in the downwarped grabens of Gondwana basins, extensive Cenozoic deposits offshore [START_REF] Bastia | Continental Margin of India[END_REF][START_REF] Chatterjee | The longest voyage: tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia[END_REF] and Neo-geneeHolocene deltaic deposits all along the east coast [START_REF] Ramkumar | Progradation of the Godavari deltada fact or empirical artifice? Insights from coastal landforms[END_REF][START_REF] Campanile | Sedimentation record in the KonkaneKerala Basin: implications for the evolution of the Western Ghats and the Western Indian passive margin[END_REF], the absence of comparable deltaic sequences in the west coast [START_REF] Kale | Geomorphic history and landscapes of India[END_REF][START_REF] Kale | The Indian Peninsula: geomorphic landscapes[END_REF], the historic and ongoing seismicity either at or in the vicinity of paleo-sutures and structures (Radhakrishna, Figure 1. Regional structural trends of the Peninsular India. This figure depicts the inheritance of structural trends from Proterozoic paleo-suture zones. These underwent reactivation during Permo-Triassic, late Jurassiceearly Cretaceous, upper Cretaceous, end Cretaceouseearly Cenozoic. Occurrences of ongoing seismicity, at or along boundary faults of sedimentary basins, deltaic systems, plateaus, escarpments, strandlines, waterfalls, knick points, terraces, etc., evidence tectonic continuum until recent [START_REF] Ramkumar | Geological, geophysical and inherited tectonic imprints on the climate and contrasting coastal geomorphology of the Indian Peninsula[END_REF]. Owing to the connectivity between subcrustal causative mechanism and progressively weakened nature, these suture zones were the zones of reactivation repeatedly, during geologic-historic-recent times. It also evidences to the subcrustal origin for them and single mechanism e subcrustal erosion and periods of intensive mantle plume activity.

M. Ramkumar et al. / Geoscience Frontiers xxx (2016) Sharma and Rajamani, 2000a;[START_REF] Valdiya | Tectonic resurgence of the Mysore plateau and surrounding regions in cratonic southern India[END_REF][START_REF] Jayalakshmi | Late pleistocene-holocene paleoclimatic history of the Southern Kerala Basin, Southwest India[END_REF][START_REF] Roy | The Phanerozoic reconstitution of Indian Shield as the aftermath of break-up of the Gondwanaland[END_REF][START_REF] Biswas | A review of structure and tectonics of Kutch basin, western India, with special reference to earthquakes[END_REF][START_REF] Mishra | Evidence for Proterozoic collision from airborne magnetic and gravity studies in Southern Granulite Terrain, India and signatures of recent tectonic activity in the Palghat Gap[END_REF][START_REF] Kale | The Indian Peninsula: geomorphic landscapes[END_REF] and absence of significant Mesozoic deposits on land [START_REF] Banerji | Post-eocene biofacies, palaeoenvironments and palaeogeography of the Bengal Basin, India[END_REF][START_REF] Ramkumar | Lithofacies and granulometric characteristics of the Kallamedu formation, Ariyalur group, South India: implications on Cretaceous-tertiary boundary events[END_REF] suggest prevalent [START_REF] Ramkumar | Deltaic sedimentation during Cretaceous Period in the Northern Cauvery Basin, South India: facies architecture, depositional history and sequence stratigraphy[END_REF][START_REF] Ramkumar | Lithofacies and granulometric characteristics of the Kallamedu formation, Ariyalur group, South India: implications on Cretaceous-tertiary boundary events[END_REF][START_REF] Ramkumar | Discrimination of tectonic dynamism, quiescence, and third order relative sea level cycles of the Cauvery Basin, South India[END_REF] and ongoing tectonic dynamism [START_REF] Jayalakshmi | Late pleistocene-holocene paleoclimatic history of the Southern Kerala Basin, Southwest India[END_REF][START_REF] Biswas | A review of structure and tectonics of Kutch basin, western India, with special reference to earthquakes[END_REF][START_REF] Mishra | Evidence for Proterozoic collision from airborne magnetic and gravity studies in Southern Granulite Terrain, India and signatures of recent tectonic activity in the Palghat Gap[END_REF].

Inheritance and tectonic continuum [START_REF] Roy | The Phanerozoic reconstitution of Indian Shield as the aftermath of break-up of the Gondwanaland[END_REF] of basement structures (Fig. 1) over climate, and landscape evolution of Peninsular India [START_REF] Radhakrishna | Neogene uplift and geomorphic rejuvenation of the Indian Peninsula[END_REF][START_REF] Valdiya | Tectonic resurgence of the Mysore plateau and surrounding regions in cratonic southern India[END_REF][START_REF] Kale | Geomorphic history and landscapes of India[END_REF][START_REF] Ramkumar | Geological, geophysical and inherited tectonic imprints on the climate and contrasting coastal geomorphology of the Indian Peninsula[END_REF] resulted in unique and diverse drainage patterns of major rivers [START_REF] Valdiya | Tectonic resurgence of the Mysore plateau and surrounding regions in cratonic southern India[END_REF][START_REF] Kale | Geomorphic history and landscapes of India[END_REF]. While most rivers of the Peninsula follow a general easterly direction, the morphology of catchments indicates youthful character [START_REF] Radhakrishna | Neogene uplift and geomorphic rejuvenation of the Indian Peninsula[END_REF]Sharma and Rajamani, 2000b) and tectonically active nature [START_REF] Radhakrishna | Neogene uplift and geomorphic rejuvenation of the Indian Peninsula[END_REF]Sharma and Rajamani, 2000a,b;[START_REF] Valdiya | Tectonic resurgence of the Mysore plateau and surrounding regions in cratonic southern India[END_REF][START_REF] Ramkumar | Progradation of the Godavari deltada fact or empirical artifice? Insights from coastal landforms[END_REF][START_REF] Jayalakshmi | Late pleistocene-holocene paleoclimatic history of the Southern Kerala Basin, Southwest India[END_REF][START_REF] Biswas | A review of structure and tectonics of Kutch basin, western India, with special reference to earthquakes[END_REF][START_REF] Mishra | Evidence for Proterozoic collision from airborne magnetic and gravity studies in Southern Granulite Terrain, India and signatures of recent tectonic activity in the Palghat Gap[END_REF]. The west coast/ Western Continental Margin (WCM) is characterized by narrow (<60 km), rocky, crenulated and coastal cliffs and pocket beaches. The east coast/Eastern Continental Margin (ECM) is characterized by wide deltas built by major rivers that show trellis to dendritic stream patterns and follow major basement faults. These faults are associated with geologic-historic-recent seismic activity [START_REF] Radhakrishna | Neogene uplift and geomorphic rejuvenation of the Indian Peninsula[END_REF]Sharma and Rajamani, 2000a,b;[START_REF] Valdiya | Tectonic resurgence of the Mysore plateau and surrounding regions in cratonic southern India[END_REF][START_REF] Ramkumar | Progradation of the Godavari deltada fact or empirical artifice? Insights from coastal landforms[END_REF]Raval and Veeraswamy, 2003a;[START_REF] Jayalakshmi | Late pleistocene-holocene paleoclimatic history of the Southern Kerala Basin, Southwest India[END_REF][START_REF] Roy | The Phanerozoic reconstitution of Indian Shield as the aftermath of break-up of the Gondwanaland[END_REF][START_REF] Biswas | A review of structure and tectonics of Kutch basin, western India, with special reference to earthquakes[END_REF][START_REF] Mishra | Evidence for Proterozoic collision from airborne magnetic and gravity studies in Southern Granulite Terrain, India and signatures of recent tectonic activity in the Palghat Gap[END_REF][START_REF] Ramkumar | Deltaic sedimentation during Cretaceous Period in the Northern Cauvery Basin, South India: facies architecture, depositional history and sequence stratigraphy[END_REF][START_REF] Ramkumar | Lithofacies and granulometric characteristics of the Kallamedu formation, Ariyalur group, South India: implications on Cretaceous-tertiary boundary events[END_REF][START_REF] Campanile | Sedimentation record in the KonkaneKerala Basin: implications for the evolution of the Western Ghats and the Western Indian passive margin[END_REF][START_REF] Kale | Geomorphic history and landscapes of India[END_REF][START_REF] Kale | The Indian Peninsula: geomorphic landscapes[END_REF]. The western boundary of ECM sedimentary basins, delta heads, strandlines and active delta lobes are always limited by basement faults [START_REF] Ramkumar | Progradation of the Godavari deltada fact or empirical artifice? Insights from coastal landforms[END_REF][START_REF] Ramkumar | Discrimination of tectonic dynamism, quiescence, and third order relative sea level cycles of the Cauvery Basin, South India[END_REF] and mobile belts [START_REF] Jayalakshmi | Late pleistocene-holocene paleoclimatic history of the Southern Kerala Basin, Southwest India[END_REF]. These faults and mobile belts have shown activity since Proterozoic [START_REF] Roy | The Phanerozoic reconstitution of Indian Shield as the aftermath of break-up of the Gondwanaland[END_REF]) and more actively from the Gondwanan times [START_REF] Banerji | Post-eocene biofacies, palaeoenvironments and palaeogeography of the Bengal Basin, India[END_REF][START_REF] Roy | The Phanerozoic reconstitution of Indian Shield as the aftermath of break-up of the Gondwanaland[END_REF][START_REF] Ramkumar | Deltaic sedimentation during Cretaceous Period in the Northern Cauvery Basin, South India: facies architecture, depositional history and sequence stratigraphy[END_REF][START_REF] Ramkumar | Lithofacies and granulometric characteristics of the Kallamedu formation, Ariyalur group, South India: implications on Cretaceous-tertiary boundary events[END_REF][START_REF] Ramkumar | Discrimination of tectonic dynamism, quiescence, and third order relative sea level cycles of the Cauvery Basin, South India[END_REF].

When it was part of Gondwanaland, the Indian subcontinent rifted during the Permo-Triassic in the form of triple rift junctions [START_REF] Banerji | Post-eocene biofacies, palaeoenvironments and palaeogeography of the Bengal Basin, India[END_REF][START_REF] Roy | The Phanerozoic reconstitution of Indian Shield as the aftermath of break-up of the Gondwanaland[END_REF] along Precambrian paleo-suture zones [START_REF] Roy | The Phanerozoic reconstitution of Indian Shield as the aftermath of break-up of the Gondwanaland[END_REF]. During late Jurassiceearly Cretaceous, separation of Africa from Gondwanaland occurred [START_REF] Chatterjee | The longest voyage: tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia[END_REF], followed by the rifting of Antarctica-Australia from Greater India consisting of MadagascareSeychelles-India during Barremian [START_REF] Roy | The Phanerozoic reconstitution of Indian Shield as the aftermath of break-up of the Gondwanaland[END_REF][START_REF] Bastia | Continental Margin of India[END_REF]Radhakrishna et al., 2012a). Separation of Madagascar-Seychelles from Greater India occurred around 88e80 Ma [START_REF] Chari | Evolution of the Cauvery Basin, India from subsidence modelling[END_REF][START_REF] Gombos | The tectonic evolution of western India and its impact on hydrocarbon occurrences: an overview[END_REF][START_REF] Yoshida | Juxtaposition of India and Madagascar: a perspective[END_REF][START_REF] Gunnell | Denudation history of the continental margin of western peninsular India since the early Mesozoicereconciling apatite fission-track data with geomorphology[END_REF][START_REF] Ramkumar | Deltaic sedimentation during Cretaceous Period in the Northern Cauvery Basin, South India: facies architecture, depositional history and sequence stratigraphy[END_REF][START_REF] Chatterjee | The longest voyage: tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia[END_REF] and the WCM and WGE evolved (Fig. 1) (Raval and Veeraswamy, 2003a,b;[START_REF] Subrahmanyam | Evolution of the passive continental margins of Indiada geophysical appraisal[END_REF].

The location of the highest peaks of the Western Ghats (Anaimudi: 2695 m ASL; Dota Petta: 2637 m ASL), exposures of Arch-aeneProterozoic deep crustal plutonic-metaigneous rocks, crustal thickness of only 29 km (Radhakrishna et al., 2000(Radhakrishna et al., , 2012a,b) ,b) and absence of significantly thick regolith in the vicinity on a regional scale (Sharma and Rajamani, 2000a,b;[START_REF] Gunnell | Denudation history of the continental margin of western peninsular India since the early Mesozoicereconciling apatite fission-track data with geomorphology[END_REF] along the southern part of the Indian peninsula, together with progressive increase of regolith over granitic and laterite over trap rocks [START_REF] Radhakrishna | Neogene uplift and geomorphic rejuvenation of the Indian Peninsula[END_REF][START_REF] Valdiya | Tectonic resurgence of the Mysore plateau and surrounding regions in cratonic southern India[END_REF][START_REF] Kale | Geomorphic history and landscapes of India[END_REF][START_REF] Kale | The Indian Peninsula: geomorphic landscapes[END_REF] toward north indicate relatively higher quantum of denudation on the surface and subcrustal erosion underneath in the south.

Thus, despite few publications on geologic-historic-recent resurgence of basement structures, control of sedimentary basin structures, deltas, coastal margins and landscape evolution by these structures since initial rifting, topographic feedback of first order tectonic events, and the geotectonic evolutionary history of the Indian subcontinent, the knowledge on the cause(s) of faster flight experienced by the Indian plate during early Cenozoic remains enigmatic.

Material and methods

Initially, interpretation of remotely sensed data and generation of a thematic map of regional geomorphology with field checks was carried out. The thematic map was superposed by digital elevation model constructed from SRTM data. The resultant composite map was incorporated with regional structural features mapped in the field and compiled from previous publications of the authors and others. Data on seismic tomography, zero free air gravity and teleseismic residuals were compiled to construct solid-lithosphere thickness heterogeneity map of the Indian subcontinent. It was followed by enlisting of major tectonic and landscape evolution events and integration of published data on crustal thicknesses and causative mechanisms of crustal thickness heterogeneity. Based on these data and maps, idealistic models were developed and discussed in the context of stages, intensity, and timing of subcrustal plume activity and resultant tectonic-geomorphic feedbacks of the Indian subcontinent.

Results

The Indian shield comprises a number of ArcheaneProterozoic cratons. In comparison with the thicknesses of shield areas elsewhere (w250e300 km; [START_REF] Srinagesh | Teleseismic tomographic evidence for contrasting crust and upper mantles beneath Archaean and Phanerozoic terrains in south India[END_REF]Raval and Veeraswamy, 2003b;[START_REF] Pandey | Deep scientific drilling results from Koyna and Killari earthquake regions reveal why Indian shield lithosphere is unusual, thin and warm[END_REF], thinnest nature of Indian crustal thickness (Fig. 2) is indicated by seismic tomography, zero free air gravity and teleseismic residuals data. Major part of the original lower crust was removed into the underlying thermally buoyant mantle due to subcrustal erosion during Proterozoic to early Tertiary (Raval and Veeraswamy, 2003b) and by surficial unroofing [START_REF] Pandey | Deep scientific drilling results from Koyna and Killari earthquake regions reveal why Indian shield lithosphere is unusual, thin and warm[END_REF]. Occurrence of 16 km thick mantle magma plume with an isotherm of w1300 C at shallow depth (w100 km) was reported signifying the continuity of plume activity (Raval and Veeraswamy, 2003b;[START_REF] Mishra | Evidence for Proterozoic collision from airborne magnetic and gravity studies in Southern Granulite Terrain, India and signatures of recent tectonic activity in the Palghat Gap[END_REF][START_REF] Singh | A review of crust and upper mantle structure beneath the Indian subcontinent[END_REF] until recent. Crustal thickness estimation from zero free air gravity anomaly showed isostatic under-compensation in the plateau regions, and negative values in the mobile belts [START_REF] Rao | Zero-free air-based gravity anomaly (preliminary) map of South India -a refined and redefined Bouguer map[END_REF]. The EGMB (Eastern Ghat Mobile Belt) region is characterized by high crustal velocity, dense crust, regional under-compensation and recurrent earthquakes [START_REF] Rao | Zero-free air-based gravity anomaly (preliminary) map of South India -a refined and redefined Bouguer map[END_REF] of >5.5 intensity. The velocity residuals computed through seismic tomography [START_REF] Sen | Deccan plume, lithosphere rifting, and volcanism in Kutch, India[END_REF] indicate the occurrences of deep rooted crust in the order of 50e175 km in northcentral India, and isolated patches along the western and highly thinned nature in southern India (Fig. 2). Crustal thicknesses of >50 km in central and restricted parts of western India [START_REF] Radhakrishna | Seismogenesis and deformation in the Deccan Volcanic province, Peninsular India[END_REF]Radhakrishna et al., 2000;[START_REF] Srinagesh | Teleseismic tomographic evidence for contrasting crust and upper mantles beneath Archaean and Phanerozoic terrains in south India[END_REF][START_REF] Rao | Zero-free air-based gravity anomaly (preliminary) map of South India -a refined and redefined Bouguer map[END_REF][START_REF] Subrahmanyam | Evolution of the passive continental margins of Indiada geophysical appraisal[END_REF][START_REF] Sen | Deccan plume, lithosphere rifting, and volcanism in Kutch, India[END_REF][START_REF] Sharma | Seismological and mineral physics constraints on the evolution of upper 660-km depth of the Gondwanaland with special reference to India and Antarctica[END_REF][START_REF] Singh | A review of crust and upper mantle structure beneath the Indian subcontinent[END_REF], <38 km in south, w30 km under the K-G Basin and 20e23 km at eastern extremity of ECM are reported. The basement below the Cauvery Basin has only a w3 km thick elastic lithosphere [START_REF] Bastia | Continental Margin of India[END_REF] whereas the basement below the K-G basin has 30 km elastic lithosphere (Radhakrishna et al., 2000(Radhakrishna et al., , 2012a,b),b). Over 10,000 km of deep seismic profiles observed from more than 600 seismic stations showed a range of crustal thickness from 29 km at the southern tip of India to 88 km under the Himalayan collision zone [START_REF] Singh | A review of crust and upper mantle structure beneath the Indian subcontinent[END_REF].

Tectonic movements along preexistent shear zones (Fig. 1) are evidenced by intraplate stress computations [START_REF] Mandal | Intraplate stress distribution induced by topography and crustal density heterogeneities beneath the south Indian shield, India[END_REF][START_REF] Mahesh | Rigid Indian plate: constraints from GPS measurements[END_REF] and the alignments of active seismic zones [START_REF] Radhakrishna | Neogene uplift and geomorphic rejuvenation of the Indian Peninsula[END_REF]Sharma and Rajamani, 2000a,b;[START_REF] Valdiya | Tectonic resurgence of the Mysore plateau and surrounding regions in cratonic southern India[END_REF][START_REF] Jayalakshmi | Late pleistocene-holocene paleoclimatic history of the Southern Kerala Basin, Southwest India[END_REF][START_REF] Roy | The Phanerozoic reconstitution of Indian Shield as the aftermath of break-up of the Gondwanaland[END_REF][START_REF] Biswas | A review of structure and tectonics of Kutch basin, western India, with special reference to earthquakes[END_REF][START_REF] Mishra | Evidence for Proterozoic collision from airborne magnetic and gravity studies in Southern Granulite Terrain, India and signatures of recent tectonic activity in the Palghat Gap[END_REF]. The Kerguelen, Crozet, Marion and Reunion plumes [START_REF] Chatterjee | The longest voyage: tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia[END_REF] interacted with the Indian lithosphere (Raval and Veeraswamy, 2003b) that led to large-scale shearing [START_REF] Singh | A review of crust and upper mantle structure beneath the Indian subcontinent[END_REF], intraplate magmatism, magma underplating [START_REF] Srinagesh | Teleseismic tomographic evidence for contrasting crust and upper mantles beneath Archaean and Phanerozoic terrains in south India[END_REF][START_REF] Sen | Deccan plume, lithosphere rifting, and volcanism in Kutch, India[END_REF], and crustal physical stretching and thinning (Fig. 2), essentially along the EGMB, ECM, WCM (Radhakrishna et al., 2000(Radhakrishna et al., , 2012b;;[START_REF] Bastia | Continental Margin of India[END_REF]Radhakrishna et al., 2012a,b). In addition, it has newly created faults giving birth to newer sedimentary basins (Figs. 1 and3) through structurally weakened pre-existent faults and shear zones (Raval and Veeraswamy, 2003b). This facilitated reactivations during synrift, post rift and collisional phases and considerably reconstituted the Indian subcontinent (Raval and Veeraswamy, 2003b). The ECM and east coast sedimentary basins formed in two stages: the first one in the region between Bengal Basin to north of Cauvery Basin resulted from initial rifting while the second in the region between the Cauvery Basin and the southern extremity of the Indian subcontinent resulted from rifting and shearing (Radhakrishna et al., 2000(Radhakrishna et al., , 2012b)). Movement of intensive plume interaction with subcrustal lithosphere proceeded from NE (present-day) of Indian subcontinent toward south and proceeded along WCM [START_REF] Sunil | Crustal structure of the western part of the Southern Granulite Terrain of Indian Peninsular Shield derived from gravity data[END_REF][START_REF] Pandey | Was Archean Dharwar craton ever stable? A seismic perspective[END_REF] before outpouring of lava through Deccan volcanism [START_REF] Hooper | Tectonic setting and timing of the final Deccan flood basalt eruptions[END_REF]. The subsidence curves developed for each of the subbasins of the Cauvery Basin [START_REF] Chari | Evolution of the Cauvery Basin, India from subsidence modelling[END_REF] showed that the initial rifting commenced from cratonic interior, evidencing subcrustal plume activity and asthenosphere anisotropy [START_REF] Srinagesh | Teleseismic tomographic evidence for contrasting crust and upper mantles in south Indian Archaean terrains[END_REF][START_REF] Srinagesh | Teleseismic tomographic evidence for contrasting crust and upper mantles beneath Archaean and Phanerozoic terrains in south India[END_REF][START_REF] Singh | Crustal structure and domain tectonics of the Dharwar craton (India): insight from new gravity data[END_REF][START_REF] Singh | A review of crust and upper mantle structure beneath the Indian subcontinent[END_REF] Q 2

. Based on the sequences of tectonic, geomorphic and drift events, an idealistic model representing stages of tectono-thermal activity and resultant geological-geomorphic feedback was constructed and presented in Fig. 4. The relatively faster drift of Indian plate in comparison with other plates [START_REF] Opydyke | Surface area control of shallow cratonic to deep marine carbonate accumulation[END_REF] is shown in the Fig. 5a. Apparent variations of drift rates [START_REF] Lippert | Early Cretaceous to Present Latitude of the Central Proto-Tibetan Plateau: a Paleomagnetic Synthesis with Implications for Cenozoic Tectonics, Paleogeography, and Climate of Asia[END_REF] of Indian plate subsequent to major plume activities and rifting phases are presented in Fig. 5b.

Discussion

The occurrence and orientation/alignment of the major sedimentary basins, deltaic systems, macrogeomorphic features such as plateaus, waterfalls, delta heads, and strandlines are all either delimited and/or aligned either on or along the major structural trends/sutures in the Peninsular India. Continued activism of these structures and sutures since Proterozoic and inception/termination of basin/delta formation, shifting of prime loci of deposition/ erosion concomitant or as a result of these activisms, continued seismicity along these structures are collectively suggestive of tectonism as the first order control over these basins, basinfills, and deltaic systems and also on their spatio-temporal distribution. Examination of these extrinsic processes and features in the light of intrinsic processes and features reveal the following.

The crustal thickness variations and subcrustal anisotropy as revealed by a variety of studies, methods and tools suggest a general increase of thickness from SeN in the peninsular region. This trend in itself is an indication of northerly tilt-uplift of the Indian plate due to thrust and isostasy. The southerly thinning could have been due to topographic unroofing (surficial erosion by extrinsic processes) and subcrustal erosion by mantle plumes. As the topographic unroofing is relatively a slow process, and is under the control of tectonics and climate, it is presumed that sudden acceleration of plate movement could not have been affected by it and hence, the intrinsic process is examined.

The initial rifting in the Gondwanaland, now recognized as failed rifts of NSL, GR, MR (Fig. 1) were the earliest evidences of subcrustal plumes induced crustal thinning and subsequent faulting events [START_REF] Srinagesh | Teleseismic tomographic evidence for contrasting crust and upper mantles beneath Archaean and Phanerozoic terrains in south India[END_REF][START_REF] Sen | Deccan plume, lithosphere rifting, and volcanism in Kutch, India[END_REF][START_REF] Bastia | Continental Margin of India[END_REF]. The late Jurassiceearly Cretaceous continental separation was indeed due to the Kerguelen plume activity [START_REF] Singh | Crustal structure and domain tectonics of the Dharwar craton (India): insight from new gravity data[END_REF], followed by Crozet plume [START_REF] Bastia | Continental Margin of India[END_REF]Radhakrishna et al., 2012b) activity both of which led to the formation of 85 E and 90 E ridges (Radhakrishna et al., 2012a), extensive trap rocks over the Precambrian basement as well as intratrappeans in the Bengal and Mahanadi basins [START_REF] Bastia | Continental Margin of India[END_REF]. Progressive intensification and movement of the plume toward south gave birth to the rifting and initiation of Cauvery Basin [START_REF] Chari | Evolution of the Cauvery Basin, India from subsidence modelling[END_REF][START_REF] Sunil | Crustal structure of the western part of the Southern Granulite Terrain of Indian Peninsular Shield derived from gravity data[END_REF][START_REF] Pandey | Was Archean Dharwar craton ever stable? A seismic perspective[END_REF]. Further movement of plume (Marion) thereon along the west rifted Madagascar during Santo-nianeCampanian [START_REF] Yoshida | Juxtaposition of India and Madagascar: a perspective[END_REF]Raval and Veeraswamy, 2003a;[START_REF] Bastia | Continental Margin of India[END_REF]. Finally, the Reunion plume activity during end-Cretaceous led to the Deccan volcanism [START_REF] Mclean | Deccan Traps mantle degassing in the terminal Cretaceous marine extinctions[END_REF][START_REF] Hooper | Tectonic setting and timing of the final Deccan flood basalt eruptions[END_REF]. All these plumes, on ascendance, significantly depleted the subcrustal portions of Indian plate all along ECM and WCM, leaving central-northern part thicker and heavier, explaining the crustal thickness heterogeneities of the Indian plate (Figs. 3 and4). While subcrustal plume controlled geodynamics along the ECM, WCM, and other preexistent rifts stand confirmed, the immediate circumstances that triggered the sudden, accelerated drift of the Indian plate require evaluation.

The occurrence of lower part of the Indian lithosphere along the Main Frontal Thrust underneath the Himalaya [START_REF] Bastia | Continental Margin of India[END_REF] and Tibet up to 31 N and a dense continental slab with higher density under Tibet might aid subduction of Indian plate under Eurasian Plate and also form a significant driving force for IndiaeAsia convergence [START_REF] Lippert | Early Cretaceous to Present Latitude of the Central Proto-Tibetan Plateau: a Paleomagnetic Synthesis with Implications for Cenozoic Tectonics, Paleogeography, and Climate of Asia[END_REF]. However, the slab pull is reinforced by the ridge-push from the spreading of the Central Indian Ridge and Carlsberg Ridge [START_REF] Patriat | India-Eurasia collision chronology has implications for crustal shortening and driving mechanisms of plates[END_REF][START_REF] Cande | Indian and African plate motions driven by the push force of the Réunion plume head[END_REF][START_REF] Van Hinsbergen | Acceleration and deceleration of India-Asia convergence since the cretaceous: roles of mantle plumes[END_REF]. The WGE, extending for about 1600 km all along the western margin, evolved during CenozoicePliestocene [START_REF] Radhakrishna | Neogene uplift and geomorphic rejuvenation of the Indian Peninsula[END_REF][START_REF] Gunnell | Denudation history of the continental margin of western peninsular India since the early Mesozoicereconciling apatite fission-track data with geomorphology[END_REF], and the MioceneeRecent tectonic uplift in the Raan of Kutchchh [START_REF] Gombos | The tectonic evolution of western India and its impact on hydrocarbon occurrences: an overview[END_REF] Movement of plumehead initially along eastern margin from Bengal Basin until the Cauvery Basin, prevalence of rifting-shearing in the Cauvery Basin, followed by movement of the plumehead along the western margin has an analogy in the form of Tanzanian craton [START_REF] Koptev | Dual continental rift systems generated by plumeelithosphere interaction[END_REF]. [START_REF] Jagoutz | Anomalously fast convergence of India and Eurasia caused to double subduction[END_REF] analytically calculated the forces related to slab buoyancy, lithostatic overburden, and viscous flow in the asthenosphere and derived the resultant changes on the subducting/drifting plate, including slab buoyancy, viscous pressure, viscous shear stress, frictional stress, and the pressure due to the overburden on the slab. It yielded a set of velocities for all the plates, a new set of velocities for each point on the slabs, and a new value for the total horizontal component of force acting on each of plate elements in the system. The numerical simulation attempted by these authors suggested the rise of the plumehead from a single mantle source and juxtaposition of magma-rich and magma-poor conditions of Tanzanian craton. We assume similar conditions for the Indian plate based on the younging nature of the rifting from NE of the ECM toward south Please cite this article in press as: Ramkumar, M., et al., Early Cenozoic rapid flight enigma of the Indian subcontinent resolved: Roles of topographic top loading and subcrustal erosion, Geoscience Frontiers (2016), http://dx.doi.org/10.1016/j.gsf.2016.05.004 followed by WCM from south toward north, culminating at the Deccan volcanism. It is noteworthy to state that the quantum and intensity of volcanism and volcanic and volcanoclastics in the sedimentary basins along the East coast show a gradual decrease and become absent in the Cauvery Basin, which experienced initial rifting and later shearing, suggestive of prevalence of magma-rich conditions during the formation of Bengal Basin and magma-poor during the formation of Cauvery Basin. After a while, rejuvenation of the magmatic activity and channeling of the rising magma toward western continental margin might have been prevalent, causing rifting along the western margin culminating at the Deccan volcanism. [START_REF] Cande | Indian and African plate motions driven by the push force of the Réunion plume head[END_REF] suggested that the mantle plumes play an important part in the Earth's tectonics, yet it has been difficult to isolate the effect that plumes have on plate motions. Based on this premise, these authors have analyzed the plate motions of India and Africa and concluded that the plate motions involved in two apparently disparate events: the unusually rapid motion of India between 67 and 52 Ma and a contemporaneous, transitory slowing of Africa's motion, and showed that the events are coupled, with the common element being the position of the Indian and African plates relative to the location of the Reunion plume head. According to these authors, the synchronicity of these events suggests that they were both driven by the force of the Reunion plume head. The recognition of this plume force has substantial tectonic implications: the speed-up and slowdown of India, the possible cessation of convergence between Africa and Eurasia in the Paleocene epoch and the enigmatic bends of the fracture zones on the Southwest Indian Ridge can all be attributed to the Reunion plume. As premised by [START_REF] Koptev | Dual continental rift systems generated by plumeelithosphere interaction[END_REF], magma rising under craton experiencing far-field stress get channeled and is why one side of the craton experiences magma-rich conditions while the other side experience magma-poor conditions, explaining the progression of magmatic activity from Bengal Basin towards west coast of the Indian Plate. [START_REF] Cande | Indian and African plate motions driven by the push force of the Réunion plume head[END_REF] hypothesized that if a rising plume head impinges on the base of a tectonic plate long after supercontinent break-up and dispersal, its pushing force may result in a substantial transient acceleration or deceleration of plates. [START_REF] Müller | Plate motion and mantle plumes[END_REF] opined that whether a plate adopts the speed depends on how the plume-push force balances out with other forces acting on the plate. Further, he was of the opinion that some recent studies suggest that the plate-driving forces that can be generated by mantle plumes are too modest to explain the acceleration of the Indian plate proposed by [START_REF] Cande | Indian and African plate motions driven by the push force of the Réunion plume head[END_REF]. In addition, the boost in speed seems to have lasted several million years longer than the surface eruptions triggered by the Réunion plume. Nevertheless, [START_REF] Müller | Plate motion and mantle plumes[END_REF] concluded that the plume-push mechanism could explain many geophysical puzzles. Similarly, van Hinsbergen et al. (2011) also concluded that the plumeascendance and resultant plate motion could accelerate drift rates of continents at several cm/yr.

Passing of the Indian plate over the Reunion hotspot [START_REF] Mclean | Deccan Traps mantle degassing in the terminal Cretaceous marine extinctions[END_REF][START_REF] Keller | Main Deccan volcanism phase ends near the KeT boundary: evidence from the KrishnaeGodavari Basin, SE India[END_REF] during 68e64 Ma led to one of the largest, yet shortest continental flood basalt volcanic episodes of the Earth. On a geological scale, it is one of the sudden upheavals [START_REF] Chenet | 40 K/ 40 Ar dating of the main Deccan large igneous province: further evidence of KTB age and short duration[END_REF]. Outpouring of >5000 m thick trap rocks in the offshore basins of west coast [START_REF] Mclean | Deccan Traps mantle degassing in the terminal Cretaceous marine extinctions[END_REF], and present-day exposures with thickness of >3500 m (after enduring >55 Ma of denudation) over the continental basement rocks [START_REF] Gunnell | Denudation history of the continental margin of western peninsular India since the early Mesozoicereconciling apatite fission-track data with geomorphology[END_REF] forming vast plateaus [START_REF] Kale | Geomorphic history and landscapes of India[END_REF][START_REF] Kale | The Indian Peninsula: geomorphic landscapes[END_REF] in the northwestern India, evidence the enormity of this episode. It is the most voluminous continental flood basaltic volcanic activity [START_REF] Mclean | Deccan Traps mantle degassing in the terminal Cretaceous marine extinctions[END_REF][START_REF] Keller | Early Danian planktic foraminifera from Cretaceous-tertiary intertrappean beds at Jhilmili, Chhindwara District, Madhya Pradesh, India[END_REF] as the areal extent of basaltic lava was 2.6 Â 10 6 km 2 , the volume [START_REF] Mclean | Deccan Traps mantle degassing in the terminal Cretaceous marine extinctions[END_REF] of the lava ejected was w1.2 million km 3 , and the CO 2 emitted into the atmosphere was w5 Â 10 17 mol. According to an estimate [START_REF] Keller | Main Deccan volcanism phase ends near the KeT boundary: evidence from the KrishnaeGodavari Basin, SE India[END_REF][START_REF] Keller | Early Danian planktic foraminifera from Cretaceous-tertiary intertrappean beds at Jhilmili, Chhindwara District, Madhya Pradesh, India[END_REF], the entire event lasted only >4 Ma and another study has estimated only 0.53e1.36 Ma [START_REF] Chenet | 40 K/ 40 Ar dating of the main Deccan large igneous province: further evidence of KTB age and short duration[END_REF] duration. Notwithstanding these differences, >80% of the flows were erupted during the last phase that lasted less than 0.8 Ma [START_REF] Keller | Main Deccan volcanism phase ends near the KeT boundary: evidence from the KrishnaeGodavari Basin, SE India[END_REF][START_REF] Keller | Early Danian planktic foraminifera from Cretaceous-tertiary intertrappean beds at Jhilmili, Chhindwara District, Madhya Pradesh, India[END_REF] during the regionally correlative C29R magnetic polarity zone [START_REF] Keller | Main Deccan volcanism phase ends near the KeT boundary: evidence from the KrishnaeGodavari Basin, SE India[END_REF]. It evidences the suddenness of this upheaval.

Withdrawal of such volumes of lava and gas from subcrustal regime and top loading of the lava material over northern part of Indian subcontinent that already had thicker (Fig. 3) and hence relatively heavier lithosphere than its southern counterpart, that was already under ridge-push [START_REF] Patriat | India-Eurasia collision chronology has implications for crustal shortening and driving mechanisms of plates[END_REF] towards north and uplift makes this event a sudden perturbation on a geological timescale, to which, no topographic and or subcrustal isostatic balance could have been established at the rate of occurrence of disequilibrium. We consider this as an isostatic instability caused by sudden (on a geological time scale) geomorphic evolution, a la, geomorphic isostasy. A rise of 1 km in the surface elevation was estimated to be required for every 6e8 km increase in crustal thickness [START_REF] Lamb | The origin of mountains e implications for the behaviour of Earth's lithosphere[END_REF], or 50e100 km decrease in the thickness of the lithospheric mantle to maintain isostatic equilibrium. The crustal thickness of Indian plate below the northern limit of Deccan volcanic province was estimated [START_REF] Srinagesh | Teleseismic tomographic evidence for contrasting crust and upper mantles in south Indian Archaean terrains[END_REF][START_REF] Srinagesh | Teleseismic tomographic evidence for contrasting crust and upper mantles beneath Archaean and Phanerozoic terrains in south India[END_REF][START_REF] Sharma | Seismological and mineral physics constraints on the evolution of upper 660-km depth of the Gondwanaland with special reference to India and Antarctica[END_REF] to be between 70 and >250 km. This thicker part, against the plumedepleted southern part that has on an average only a 2 km thick granitic-gneissic upper crust underlain by 24 km thick intermediate to mafic middle crust (Raval and Veeraswamy, 2003b) (even if higher thickness as compared to that of present day is assumed, the thickness difference between depleted and trap rock top loaded northern part against plume-depleted southern part should have existed) tilted the Indian plate towards north, and rapidly as the solid crust was floating (Raval and Veeraswamy, 2003b) over plastic, thermally stratified asthenosphere (Fig. 4). In addition, the pressure-temperature related physical instability in the asthenosphere beneath the Indian plate aided the sudden tilt and or sliding toward north.

Thus, this sudden instability introduced to the Indian plate buoyed and accelerated the northerly drift which in turn was aided by the tilt from west and the ridge-push [START_REF] Patriat | India-Eurasia collision chronology has implications for crustal shortening and driving mechanisms of plates[END_REF]. As density contrast between the lithospheric mantle and underlying less dense asthenosphere plays an important role in the elevation of mountain belts, and isostatic compensation [START_REF] Lamb | The origin of mountains e implications for the behaviour of Earth's lithosphere[END_REF] and mobility of the lithospheric crust, the acceleration of drift was initiated by this density difference, attenuated due to the outpouring of lava in the aftermath of end-Cretaceous volcanism. Enhanced fluidity and dècollement between the partially molten lithospheric crust of the Peninsula that was floating over the ascendant plume and the thermally-stratified asthenosphere (Fig. 4) utilized the inertia provided by the buoyant plate to drift toward north. Owing to the thermal stratification of plume and asthenosphere under the Indian plate [START_REF] Srinagesh | Teleseismic tomographic evidence for contrasting crust and upper mantles beneath Archaean and Phanerozoic terrains in south India[END_REF] the viscous layer acted as a lubricant between the solid lithosphere (that was being buoyed) and the plumehead-asthenosphere. [START_REF] Müller | Plate motion and mantle plumes[END_REF] and [START_REF] Van Hinsbergen | Acceleration and deceleration of India-Asia convergence since the cretaceous: roles of mantle plumes[END_REF] are of the opinion that the ascendance of plume itself might have contributed towards several cm/yr of drift. Collectively, the geomorphic isostatic imbalance following outpouring of lava from Deccan volcanism, and prevalence of heavier lithosphere over thermally stratified crust might have aggravated the situation and initiated the accelerated drift of the Indian plate, due to the trigger e the Deccan volcanism. From Figs. 3, 4 and 5, it is also perceived that with the progressive shedding of microplates namely Madagascar and Seychelles from initial landmass separated from Gondwana (Greater India), the Indian plate became lighter and the rate of drift also became faster. Coincidences of these extraordinary and favorable milieus explain the fastest flight of India since end-Cretaceous volcanism until collision during Eocene [START_REF] Chatterjee | The longest voyage: tectonic, magmatic, and paleoclimatic evolution of the Indian plate during its northward flight from Gondwana to Asia[END_REF].

Conclusions

(1) A sequence of tectono-geomorphologic evolutionary events, commencing from Gondwana supercontinent is proposed. The Indian subcontinent was part of the Gondwana supercontinent and had inherited basement structures since Permo-Triassic. It was dismembered into microplates such as Madagascar and Seychelles and differentiated into various basins along ECM. (2) These separations and differentiations were essentially due to crustal thinning as a result of subcrustal plume erosion beneath the lithosphere. Owing to the subcrustal erosion, that proceeded from NE (present day) towards south and along the western margin, culminating with end-Cretaceous volcanism, the southern, western and eastern extremities became relatively thinner than the northern part of the Indian plate (Figs. 3 and4).

(3) Extrusion of enormous quantities of basaltic lava within a short duration during end-Cretaceous initiated an extraordinary sequence of events, among which accelerated drift of Indian plate toward north was more dramatic and unique. Buoyed by the relatively thicker lithosphere in the northern part against plume-depleted southern-eastern-western parts with fluidized, partly molten lower crust floating over thermallystratified asthenosphere, the Indian plate started gliding toward north in order to isostatically compensate for the physical instability below that was exacerbated by extruded basaltic rocks as topographic top load. (4) The buoyant plate aided by the Carlsberg and Central Indian ridge-push and resultant uplift of southern India experienced tilt toward north and accelerated drift. The northern-eastern tilt-drift continued during collision and continues till recent, probably sustained by the sediment top loading by the Ganges-Brahmaputra, that accounts for more than 70 km thick sediment pile [START_REF] Mikhailov | Processes of delta formation in the mouth area of the Ganges and Brahmaputra Rivers[END_REF] in the NE part of the Indian subcontinent. (5) This sudden acceleration has wider implications in terms of modeling plate reorganization studies elsewhere. In addition, the acceleration has impacted many other processes-eventsfeatures such as overall development of the Indian plate, shortening of time duration between separation of Greater India from Gondwanaland and collision with Eurasia, rapid exhumation of Tethys Sea sediments than it could have occurred, structural style and evolutionary history of the Himalayas and associated evolution, demise and dispersal of oceanic and continental biota. (6) We conclude that plate reorganization and lithospheric top loading interact through complex, often inexplicable processes and feedbacks, and occur at highly variable spatio-temporal scales. As demonstrated by the schematic model and the variable rates of drift, the intrinsic process could be sudden and dramatic, and the extrinsic processes could be long lasting and at variable rates. Recognition and discrimination of these should be an integral part of any plate reorganization and topographic feedback modeling.

Figure 2 .

 2 Figure 2. Spatial distribution of crustal thickness of Peninsular India and sediment thickness in the Arabian Sea and Bay of Bengal. Note the relatively thicker lithosphere in the northern part than the south. The continental margin (east and west) are thinner than the north central part. Progressive increase of sediment thickness in the BOB that reaches upto 24 km and forming sediment top load along NE part of the subducting Indian plate could also be visualized. Studies have estimated accumulation of 70 km sediment thickness since hard collision of Indian plate with Eurasian plate.

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 3 June 2016 ■ 3/9 Please cite this article in press as: Ramkumar, M., et al., Early Cenozoic rapid flight enigma of the Indian subcontinent resolved: Roles of topographic top loading and subcrustal erosion, Geoscience Frontiers (2016), http://dx.doi.org/10.1016/j.gsf.2016.05.004

Figure 3 .

 3 Figure 3. Schematic diagram of tectonic-climatic-sedimentation processes of east and west coasts of India. ① Initial failed rift along Narmada eSon rift, GR and MR (refer Fig.1) during Permo-Triassic. These rifts along the Proterozoic structures formed the loci of continental and coastal marine deposits of Gondwana sequences. ② Upper Jurassic rifting occurred initially at the NE (Bengal Basin) and proceeded towards south, creating Mahanadi Basin and the Krishna-Godavari Basin. The basement in these basins is superposed and intruded by volcanic and igneous rocks respectively, followed by extensive intratrappean sedimentary rocks, suggestive of rifting as a result of subcrustal processes and well-differentiated nature of horsts and grabens. Occurrences of the structural trends that resulted due to this rifting either along and/or aligned parallel to preexistent Gondwana trends which in turn were inherited from Proterozoic structural trends (EGMB; refer Fig.1), suggest continuum of subcrustal process. ③ Rifting and shearing during Barremian along the Proterozoic structural trends (EGMB; refer Fig.1), in the southern extremity. Absence of comparable volcanic and intrusive rocks and the presence of half-graben structure in the Cauvery Basin suggest reduction of intensity of subcrustal process. ④ Rifting and associated separation of Madagascar during SantonianeCampanian. ⑤ Deccan volcanism and outpouring of w5 km thick trap rock within short duration and sudden topographic top loading. ⑥ Northerly tilt of buoyant, thicker crust top loaded with trap rock (refer Figs.2 and 4). It was associated with NeE directed ridge-push from Carlsberg ridge and uplift and northerly ridge-push from Central Indian ridge. All these accelerated the northward flight of the Indian Plate. ⑦ Continued flight of the Indian plate under the influence of geomorphic isostasy, ridge-push and sediment top loading at NE.

  evidence the easterly tilt (Banerjee et al., 2001; Chatterjee et al., 2013), at the

Figure 4 .

 4 Figure 4. Schematic diagram showing the crustal thickness heterogeneity, the path of plume movement and plume induced subcrustal erosion. T1, T2, T3 and T4 indicate the time slices (Refer Figs. 1 and 3) and zones of significant plume erosion and resultant sub-crustal tectonics. Middle inset diagrams depict the subcrustal erosion due to intensive plume activity. Cross section AeA 0 drawn along NeS of the Indian plate as depicted in the top inset is shown in the bottom inset diagram, explaining the resultant rifting, basin formation, differentiation, topographic feedback and geomorphic isostatic compensation. It also depicts how the dècollement layer might have acted as a lubricated surface, on which, the top loaded (by trap rock during end-Cretaceous) and isostatically imbalanced Indian plate slid and commenced the faster flight.

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 3 June 2016 ■ 5/9 Please cite this article in press as: Ramkumar, M., et al., Early Cenozoic rapid flight enigma of the Indian subcontinent resolved: Roles of topographic top loading and subcrustal erosion, Geoscience Frontiers (2016), http://dx.doi.org/10.1016/j.gsf.2016.05.004 macrogeomorphic scale. Together with the structural trends and geological information, it can be surmised that the Indian subcontinent as a whole experiences thrust and tilt from south since rifting from Gondwanaland perhaps due to its continued northerly flight and rift and tilt towards NE from west since collision with Eurasia.

Figure 5 .

 5 Figure 5. Drift rates of the Indian plate with reference to other continents and time. (a) Relatively different and faster nature of drift history of the Indian plate as compared to other continents is shown by the plot of their paleo-latitudinal positions since 500 Ma. (b) Paleo-latitudinal positions of the Indian plate since 130 Ma. Note the sudden changes in drift rate, immediately after subcrustal erosion events (compare with Figs. 3 and 4) and fastest rate after Deccan Volcanism (T4).

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  Please cite this article in press as: Ramkumar, M., et al., Early Cenozoic rapid flight enigma of the Indian subcontinent resolved: Roles of topographic top loading and subcrustal erosion, Geoscience Frontiers (2016), http://dx.doi.org/10.1016/j.gsf.2016.05.004

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cite this article in press as: Ramkumar, M., et al., Early Cenozoic rapid flight enigma of the Indian subcontinent resolved: Roles of topographic top loading and subcrustal erosion, Geoscience Frontiers (2016), http://dx.doi.org/10.1016/j.gsf.2016.05.cite this article in press as: Ramkumar, M., et al., Early Cenozoic rapid flight enigma of the Indian subcontinent resolved: Roles of topographic top loading and subcrustal erosion, Geoscience Frontiers (2016), http://dx.doi.org/10.1016/j.gsf.2016.05.004

Acknowledgments

Understanding on this fascinating field of research has been aided by the articles cited in this paper and also many others which do not find place in the reference list. Authors place on record deep sense of regard for all these authors. The critical review and constructive comments and suggestions made by the anonymous reviewers and Associate Editor Dr. E. Shaji are thankfully acknowledged.


domain: sdv info math scco

text:
Fionn Murtagh

Giuseppe Iurato

The Process of Consciousness and Its Evolution Arising from Granulation and Bilogic

Keywords: Process mining, text mining, psychoanalysis, Matte Blanco Bilogic, causality and foundations of Big Data analytics, ternary -3-adic data coding, analytical focus and orientation

Our objective is to seek symmetry originating in the unconscious, and that is expressed here as reporting in consciousness. The association of psychological constructs that are consciousness and unconscious are to be both understood and interpreted within Ignacio Matte-Blanco's theory and his Bilogic framework. We carry out text mining, using extensively recorded dream reports. The texts themselves, and all the content, termed word corpus, are mapped into real-valued semantic, factor space, using Correspondence Analysis that can also be termed Geometric Data Analysis. Factors can be interpreted. For granulation, this new development is carried out: for texts and words, their factor projections are ternary encoded, to express commonality and exceptionalism. Then determined are clusters of terms and of words with semantic identity. Hence an innovative approach to granulation, and mostly with linear computational complexity. The study here establishes new implementation in analytical methods, and is also to have definite reproducibility in other, relevant and associated domains.

Introduction

Resolution scale is a most important basis for analytical work and for implementation. Overly aggregating data however, while computationally beneficial, may lead to ethical considerations (O'Neill, 2016). In Correspondence Analysis, also referred to by some authors as Geometric Data Analysis (cf. [START_REF] Murtagh | Data Science Foundations: Geometry and Topology of Complex Hierarchic Systems and Big Data Analytics[END_REF], qualitative data, with possibly also quantitative data, all is mapped onto a Euclidean metric-endowed factor space. So that is a geometric and semantic space mapping. In the fifth section, we use selected attributes, a word set here, which are personal names, to create the factor space, and then with all other attributes, from the work corpus here, mapped into the factor space. Then the mapped, both observations constituting the rows in the matrix to be analyzed, and the following constituting the columns in the matrix to be analyzed, attributes, possibly in applications to be termed variables or modalities of response to a questionnaire or survey.

A very frequent analytical method used in the factor space, quite possibly for the active attributes for creating the factor space properties, and for the observations, or respondents, or whatever constitutes the rows of the analyzed matrix, or for the collective mappings that have also the supplementary attributes that can be contextual data, very often the best analysis to pursue is hierarchical clustering, which is very essential in any or all complex systems [START_REF] Murtagh | Data Science Foundations: Geometry and Topology of Complex Hierarchic Systems and Big Data Analytics[END_REF]. The court case in the following, Bécue-Bertaut et al. (2014), is the closing speech delivered by a prosecutor at Barcelona Criminal Court. The text narrative in a court case undergoes hierarchical clustering that is adjacencyconstrained, and that is also in practice, chronological hierarchical clustering. That is, the singleton nodes, also termed the tree's leaves, are always displayed at the bottom of the rooted tree forming the hierarchy. Essentially at issue in that publication was partitioning of the chronological hierarchical clustering. In [START_REF] Murtagh | Semantic Mapping of Discourse and Activity, Using Habermas's Theory of Communicative Action to Analyze Process[END_REF], in the factor space, analysed were initiating tweets, relating to environmental and lifestyle practice and the resulting and outcome tweets, so seeing what initiating tweets had the best or the less good consequences.

In this work, used will be dream reports over a long period of time that are in a repository, [START_REF] Dreambank | Repository of dream reports[END_REF]. For the dream reports used, some description of the individual at issue is in [START_REF] Domhoff | Barb Sanders: Our best case study to date, and one that can be built upon[END_REF]. There is much also in the Barbara Sanders Interview (no date).

Granular computing and Matte Blanco's bilogic

Information granules of human psyche may be considered as a set of minimal entities (which next aggregate in clusters) that convey information given by a Matte Blanco bilogic structure (Matte [START_REF] Blanco | The Unconscious as Infinite Sets. An Essay in Bi-Logic[END_REF]; chapter 5 in Murtagh, 2017; Murtagh and Iurato, 2016; Iurato, 2018) mainly having a basic, irreducible oppositional nature. Information granulation is a process of abstraction through which one just identifies elements that are similar in terms of their functional, spatial or temporal proximity, so they are at the early basis of our perception; these elements are said to be information granules. Formally, information granules are simply represented by a function of the general type G : X → G(X) which to each object (to be meant in the sense of category theory) X associates a formal framework of related information granules (e.g., if X is an arbitrary set, then G(X) = P (X), where P (X) is the set of parts of X). (Bargiela and Pedrycz, 2003, chapter 1). At the start of the Preface in Matte [START_REF] Blanco | The Unconscious as Infinite Sets. An Essay in Bi-Logic[END_REF], mathematics is associated with psychoanalysis, and in [START_REF] Murtagh | Mathematical representations of Matte Blanco's bilogic, based on metric space and ultrametric or hierarchical topology: towards practical application[END_REF], this is pursued a lot further, using in particular, ultrametric ontology, which is a mathematical context for all that is in or with hierarchical clustering. Genealogy can be considered as hierarchical clustering. In [START_REF] Iurato | Formal foundations for the origins of human consciousness", p-Adic Numbers[END_REF], there is a very clear description, mathematically, of the origin and development of human consciousness.

On the other hand, human beings granulate information in a deep, subconscious manner (Bargiela and Pedrycz 2003, chapter 6), and this justifies the possible use of psychoanalytic tools and concepts to study this process of making information. In particular, Matte Blanco's bilogic is suitable to be considered as a possible framework in which such a granulation process takes place, if we consider this as occurring in the formation of irreducible, basic units of bilogic information made by the union of a symmetric part (related to unconscious realm) with an asymmetric one (related to consciousness), to be precise considering this last as a kind of net of asymmetric relations enveloping a certain content of symmetric thought (unconscious), so we may consider the latter as an object X to which is associated, just according to bilogic rules, a net of relations regarding it, say G(X), a kind of lattice surrounding X. Maybe, the following analogy may explain better this last fact: an arbitrary material object X may be seen by humans only if light rays cast on this object X hence they return, by reflection/diffusion, on our eyes, in a geometrical setting G(X) which will be then transduced by our neuroperceptive system until up to become an image of consciousness. So, this bilogic information process is formally analogous to that of information granulation, as described above. So, after having clarified minimally what possible links may hold between Matte Blanco psychoanalytic theory and granular computing, we go on deepening these relationships, taking into account the other, information granulation, already.

Mapping One's Thinking and Activity Here with Dream Reports

Much dream reporting is available from [START_REF] Dreambank | Repository of dream reports[END_REF]. Analytics of this data is described in [START_REF] Domhoff | Studying dream content using the archive and search engine on DreamBand.net[END_REF]. A predominent person is Barbara Sanders (the first name is often Barb) and there is description of her in [START_REF] Domhoff | Barb Sanders: Our best case study to date, and one that can be built upon[END_REF]. About her is marriage and some children but then separation from her husband, and some interest in other males. We use this textual data reporting on lifestyle, of course with dreams having certain orientations, and dream fundamentals are related to the unconscious, but both recorded here, and with reminiscence, all is converted or at least expressed, not directly as unconscious logic but more as an expression of conscious logic. Our main objective in this analysis is to have such a data source, hence such a lifestyle narrative.

Our objective then, in our analytics, is to map out the narrative evolution. First the set of dream reports and the word set, with frequencies of occur-rence of each of the words, the fundamental and creative mapping of a selected set of names, will be carried out. This creates a factor space, that also can be termed a latent, hence foundational, semantic space. For the frequencies of occurrence data, "profiles" are most at issue, and these are with frequency of occurrence values related to the total number of values. The chi squared metric is used for the profiles, of frequency of occurrence data, and that is mapped into the factor space that has the Euclidean metric. This method is Correspondence Analysis, also in some books, termed Geometric Data Analysis, and in many domains of application, initial development and application work was carried out by Jean-Paul Benzécri and, in social science, by Pierre Bourdieu. While factors are interpreted, using the observations and attributes with the highest contribution to inertia of the axes, usually hierarchical clustering is also carried out in the analytical process. Cf. [START_REF] Murtagh | Data Science Foundations: Geometry and Topology of Complex Hierarchic Systems and Big Data Analytics[END_REF].

An important practical approach for the mapping of qualitative data, that can include also quantitative data, mapping into the factor space, is the determination of the factor space using active variables and possibly active observations. Then there follows the mapping into the factor space of all other variables and observations that are then termed as supplementary and, possibly also, termed as contextual. All the mapped data can therefore contribute to interpreting the causality that results in the data.

Furthermore, if the active variables and possibly active observations are quite possibly aggregated data, the method used here can both fully relate aggregated data and individual data, and therefore more individual information is not lost by being aggregated, as described in O'Neill (2016).

For narratives, some important references are as follows. In Bécue-Bertaut et al. (2014), the concluding presentation by the legal attorney in a court case was analysed using hierarchical clustering that was chronological, having the hierarchy's leaves or singleton clusters in chronological order. Other narratives in the U.S. Supreme Court were under investigation in [START_REF] Murtagh | The structure of argument: Semantic mapping of U.S. Supreme Court cases[END_REF]. In Murtagh, Pianosi and Bull (2016), we examined Twitter tweets, in the factor space determining how an initiating tweet was related to all other tweets in a given time period.

Here, we extend the following method from Murtagh and Iurato (2018). Semantic relations and hence clusters were determined and listed. That included related words used with personal names. This is the essential method here. From the factor space, for each factor with perhaps a selected number of the most important factors used, we investigate all that is projected both positively and negatively on a factor, and what is near zero on a factor. The latter expresses commonality and lack of exceptionality or any such form of being unique and anomalous, and hence exceptional. Thus for the ranked factors, each factor in turn provides the positive projections for exceptionality, the "at or near zero" projections for commonality and shared properties, and the negative projections for exceptionality. Thus each factor has three clusters. There is the factor ranking, from the eigenvalues that relate to the inertia of the axes that form the factors. From the factor ranking, a ternary hierarchical clustering is formed. Rather than partitioning by taking some level of the hierarchy, as is standard in agglomerative hierarchical clustering that is a binary hierarchy, here we have a divisive ternary hierarchy. For clusters that can constitute a partition, we determine identity of cluster memberships at all levels of the ternary hierarchy.

In addition here, this is to be a chronologically sequenced hierarchical clustering: from a ternary hierarchical clustering, we will examine the narrative or evolution of the dream reports. This is a novel approach, seeking to have essentially qualitative data, and with characterisation in regard to specificity and exceptionalism contrasted with standard commonality. In a later section, we will look for repeated dreams with this specificity or exceptionalism, so that these can be considered as Matte Blanco's symmetric logic of the unconscious. This analytics then is contrasted to Domhoff and Schneider (2015) using autocorrelation of time series.

Narrative from Dream Reports

In [START_REF] Murtagh | Core Conflictual Relationship: Text Mining to Discover What and When[END_REF], there are 421 dream reports from 2 December 1960 to 17 February 1989, and each dream report has between a few words and about 900 words. In total there, these 421 dream reports have 3789 words, potentially comprising a word corpus and examined for relationships and also the relationships with the factors in the semantic factor analysis space. Word symmetries, hence forming, and being determined as, granular clusters here, this was done for these personal names: mother, father, and names that were daughter, youngest daughter, oldest daughter, ex-husband, two brothers, two female friends, boyfriend.

For comparability and so on, it is required that each word in the word corpus here is at least five times used. It is natural that many words are used in some dream reports only, so that the dream reports crossed by the set of retained words is this here: 1568 retained words for the 421 dream reports; the number of non-zero frequencies are 37344, i.e. the times that a word is one time or more than that in a dream report; and that is 5.657% of the set of dream reports crossed by the word set here.

(oldest daughter), Darryl (boyfriend, was to be married, but marriage was instead to Howard), Lucy (a very good friend who was interviewed), Jake (younger brother), Lydia (sister), grandma, Bonnie (long-time friend), husband, Terence, grandfather, mom, Paul, boyfriend, Rochelle (met as a performer), Peter (Pete was a former boyfriend), grandpa, grandmother, Tyler, Judy, Valerie Agnes, Weren, George, Kathleen, Jerome, Andrea, Arthur, Rosemary, Patricia, Dylan, Willie, Harrison, Charla (daughter), Naomi, Elizabeth, Diane.

The 43 names are the active variables here, and the other words used are to be the supplementary set, with 1525 words. This must be checked: with words here that occur five or more times in dream reports, can there be any dream reports with no words retained here. We find two such dream reports, from 29 Dec. 1980 and 26 Dec. 1984. Dream reports with zero contents here must be removed, so therefore the 43 active variables, i.e. the 43 names above, and the 1525 other words, these will be in the analysis, and 419 dream reports.

The Correspondence Analysis creates the factor space from the active variables (43 names) and then maps the supplementary variables (the other 1525 words) into the factor space. The 419 dream reports are active here. The first factor plane has percentages of inertia, obtained from the eigenvalues here, as 4.11 and 4.04 percent of the total inertia, here the sum of eigenvalues. On factor 1, well away from the origin (zero projection), there is the name Harrison, and on factor 2, well away from the origin, there is the name Diane, and respectively associated with these are the dream reports from 12 Feb. 1981 and 29 Dec. 1987. This can be informally expressed as the first, most important, factor is essentially that name and that dream report; and the second factor is essentially that other name and that other dream report.

We could continue to characterise every factor, but a better oriented analysis is to be the following. We will use the first thirteen factors, since all of these have more than 3% inertia, and the cumulative percentage of inertia for these factors is 46.255%.

In Figure 1, the name Harrison is very positively projected on factor 1, and the dream report from 12.02.1981; and the name Diane is very positively projected on factor 2, and the dream report from 29.12.1987. Given the "cloud" of 421 dream reports, the rows of the matrix here, and the "cloud" of 43 active names, therefore the number of factors is one less than the minimum of these, therefore 42 factors. The 13th eigenvalue is 0.6339, and that is 3.02 percent of inertia, and the cumulative percentage of inertia is 46.25. We take 13 factors for this initial analysis. The names of the active columns, active for creating the factor space, these are, as indicated above: "mother" "father" "Ellie" "Howard" "Dwight" "Paulina" "Ginny" "Dovre" "Darryl" "Lucy" "Jake" "Lydia" "grandma" "Bonnie" "husband" "Terence" "grandfather" "mom" "Paul" "boyfriend" "Rochelle" "Peter" "grandpa" "grandmother" "Tyler" "Judy" "Valerie" "Agnes" "Weren" "George" "Kathleen" "Jerome" "Andrea" "Arthur" "Rosemary" "Patricia" "Dylan" "Willie" "Harrison" "Charla" "Naomi" "Elizabeth" "Diane" Hierarchical clustering, with Ward's minimum variance method, using the shake leans king figured mid shape share q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q qq q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q qq q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q qq q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q qq q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q qq q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q qq q q q q q q q q q q q q q q q qq q q q q q q q q q q q q q q q q q q q q q q q q Figure 1: 419 dream reports; 43 names; 1525 other words; principal factor plane here. Percentages of inertia of the clouds for factors 1 and 2: 4.11 and 4.04.

CA factor map

In the text, noted are the names and dream report dates that are with very positive projections on factors 1 and 2. 13-dimensional factor space, this is shown in Fig. 2. We see that "Mom" and "mother" are quite close in their cluster agglomeration, and so are "grandpa" and "grandma", and in regard to Fig. 1, the names of "Diane" and "Harrison" here are the most separate from all other names. We can partition this hierarchy, or dendrogram.

Diane

From the factor projections in the 13-dimensional factor space, ternary coding was carried out, as follows: a projection on a factor >= 1 was a value 2; a projection <= -1 was a value 1; and a projection at or close to the origin, i.e. zero-valued or greater than -1 and less then 1, that was a value 0. A traditional binary hierarchical clustering was carried out on the ternary coded factor space mapping, and this is displayed in Figure 3. That hierarchical clustering method is Ward's minimum variance method, and it is a binary hierarchy, from the agglomerative clustering, where clusters, starting with the singleton clusters are to be merged at each of the n -1 levels in the hierarchy for n objects, here the 43 names, to be clustered.

It is seen in Figure 3 that, from the ternary data coding, "Valerie" and "Patricia" are identical in their ternary data coding, so that they have a zero distance here. Also a cluster of seventeen names was formed with their zero distances which implies identity of the ternary data coding. These seventeen names are: "mother, father, Ellie, Dwight, Lydia, grandma, Bonnie, husband, mom, boyfriend, Peter, grandpa, Agnes, Weren, George, Willie, Naomi". They are clear in Figure 3. If there were a ternary hierarchy displayed here, then these seventeen names would be in the cluster labelled zero for each of the 43 -1 levels in the hierarchy. These names are a set of names that are, for all factors, at or close to the factor's origin, therefore being common, standard, and with symmetry of the unconscious during one's dreaming. If a ternary hierarchy was to be displayed, then there would be the root node of all names having three sub-nodes and all the seventeen names mentioned above are in the zero (ternary value here, being node cluster with label 1, 0, or 2). The ternary hierarchy's display would be, for factor 1, three nodes, for factor 2, three sub-nodes for the previous three nodes, then for factor 3, three sub-nodes for the previous three squared (hence nine) number of nodes. So, in all, with many cluster nodes being empty, there would be 3 13 singleton nodes, therefore 1594323 singleton nodes, but many empty nodes. That leads to the total amount of nodes, many being empty, being 3 + 3 2 + 3 3 + etc. and that gives 2391483 nodes. Again to emphasise, many nodes are empty.

In [START_REF] Murtagh | Core Conflictual Relationship: Text Mining to Discover What and When[END_REF], other words that are mapped onto the same ternary coding of the factor space were determined and listed. Here, from the 1525 other words, 1217 words were for all 13 factors with a 0 coding, that is at or beside the origin. Here, 308 words are not with a 0 ternary coding for all factors and we can, if needed investigate those. It may be best to select certain words and then check their factor space mapping properties.

One other investigation that will be carried out is to see about the evolution of the dreams, from semantic identity of dream reports which can be also interpreted here as observed symmetric reasoning, and therefore symmetric logic of the unconscious, sleeping, status.

In Figure 4, the 419 dream reports, with mapping into the 13-dimensional factor space, these projections are ternary coded, having 0, 1, 2 for, respectively, at or close to the origin, negative ≤ -1, positive ≥ 1. The binary hierarchy here, from Ward's minimum variance method, using agglomerative hierarchical clustering, it can be used for determining clusters to be derived. Here, from the ternary hierarchy, they will be identical clusters at all levels, therefore semantic identity from the factor space based on ternary coding.

Here: for each dream report in the sequencing, we have 13-dimensional ternary coding of each dream report. This is to be considered with minus the next dream report, and then to determine what dream reports minus the next dream report have a zero value, i.e. that the two dream reports in sequence are identical. We find 95 from the 419 dream reports that are identical to each other in sequence. inertias, and the factors. The computational complexity is M 3 . For the ternary encoding and for determining clusters from identity in ternary coded, referred to here as newly determined granules, all of this processing can be of linear computational complexity.

Conclusion

An objective of this work is to show how Matte Blanco's bilogic may fit computational granulation. The formation of bilogic units of consciousness may be formally seen as a granulation process. Therefore the possible process of formation of consciousness is by means of granulation and bilogic. Inherent in the analytical process is (i) semantics and (ii) granular clusters. From this work, this can be stated: consciousness arises from a granular process through the bilogic route, and hence acquiring meaning through clusterisation and semantisation.

The new development here of ternary encoding of factor projections, based on commonality and exceptionalism in the factor space, the former, commonality, being at or very close to the factor origin, i.e. zero valued, and the latter, exceptionalism, being certainly and possibly also largely positively projected on the factor or negatively projected on the factor. It is interesting here how what is established as granules (computational in the analytical process, and also interpretative) can be determined through identity in their ternary encoding from the semantic factor space mapping. General work of this sort, using "accurate inferences" and "using traditional forms of content analysis" are in [START_REF] Domhoff | Studying dream content using the archive and search engine on DreamBand.net[END_REF].

A very major objective here also is to have Big Data sources, so that there will be a very well planned analytical focus, cf. active variables in the factor space creation, and all that is granulation here.

Figure 2 :

 2 Figure 2: Hierarchical clustering of 43 names in a 13-dimensional factor space.

  coded: 419 dream reports, 13-dim. factor space hclust (*, "ward.D2") dist(alldreamsternary) Height

Figure 4 :

 4 Figure4: 419 dream reports in 13 dimensions factor space; projections are ternary encoded. For negative projection, 1; for positive projection, 2; for at or near 0, 0. Here Ward's minimum variance agglomerative hierarchical clustering, Euclidean distance.

Word Corpus from Succession of Dream Reports, Mapping into Euclidean Metric Endowed Semantic, Factor SpaceIn order to focus the analysis carried out, the name set was focused on. The name set selected was as follows. There are 43 names, and many of them are described here, as follows: mother, father, Ellie (middle daughter), Howard (ex-husband), Dwight (older brother), Paulina (youngest daughter), Ginny (one of her best friends), Dovre

Consider n dream reports, and the obtained word corpus with m words, and the matrix with frequency of occurrence will often have a small percentage of non-zero values. Having a set of active words, to focus the factor space mapping, if there are M such active words, then the factor space is created with singular value decomposition, to have eigenvalues and eigenvectors, respectively the axis