Tectonics of the Himalaya and southern Tibet from two perspectives

Hodges, Kip

doi:10.1130/0016-7606(2000)112<324:tothas>2.0.co;2

Cited by 1,080 publications

(695 citation statements)

References 227 publications

Supporting

Mentioning

675

Contrasting

Unclassified

Order By: Relevance

“…This model provided a plausible mechanism to explain both the double crustal thickness of Tibet and surface uplift of the plateau. Subsequent geological mapping and structural studies in the Himalaya showed that the Himalayan range is composed of folded and thrust Neoproterozoic to Palaeogene rocks that in the middle crustal levels were metamorphosed to Barrovian-facies metamorphic rocks during the OligoceneMiocene (Searle et al 1997a;Hodges 2000). The ArchaeanMesoproterozoic Indian plate lower crust that originally underlay the Phanerozoic passive margin sediments prior to the IndiaAsia collision is never exposed along the Himalaya and must therefore have underthrust the Tibetan Plateau to the north after the collision (Fig.…”

Section: Crustal Deformation Models For Tibetmentioning

confidence: 99%

Crustal–lithospheric structure and continental extrusion of Tibet

Searle

Elliott

Phillips

et al. 2011

JGS

237

154

View full text Add to dashboard Cite

Crustal shortening and thickening to c. 70-85 km in the Tibetan Plateau occurred both before and mainly after the c. 50 Ma India-Asia collision. Potassic-ultrapotassic shoshonitic and adakitic lavas erupted across the Qiangtang (c. 50-29 Ma) and Lhasa blocks (c. 30-10 Ma) indicate a hot mantle, thick crust and eclogitic root during that period. The progressive northward underthrusting of cold, Indian mantle lithosphere since collision shut off the source in the Lhasa block at c. 10 Ma. Late Miocene-Pleistocene shoshonitic volcanic rocks in northern Tibet require hot mantle. We review the major tectonic processes proposed for Tibet including 'rigid-block', continuum and crustal flow as well as the geological history of the major strikeslip faults. We examine controversies concerning the cumulative geological offsets and the discrepancies between geological, Quaternary and geodetic slip rates. Low present-day slip rates measured from global positioning system and InSAR along the Karakoram and Altyn Tagh Faults in addition to slow long-term geological rates can only account for limited eastward extrusion of Tibet since Mid-Miocene time. We conclude that despite being prominent geomorphological features sometimes with wide mylonite zones, the faults cut earlier formed metamorphic and igneous rocks and show limited offsets. Concentrated strain at the surface is dissipated deeper into wide ductile shear zones.

show abstract

Section: Crustal Deformation Models For Tibetmentioning

confidence: 99%

Crustal–lithospheric structure and continental extrusion of Tibet

Searle

Elliott

Phillips

et al. 2011

JGS

237

154

View full text Add to dashboard Cite

show abstract

“…The end of marine sedimentation and the first onlap of fluvio-deltaic sediments and redbeds on the Indian northern passive margin in the western Himalaya is dated as foraminiferal Zone P8 (38), correlative with Chron C22r of latest Early Eocene age [Ϸ50.5 Ma (39,40)]. This first direct timing constraint on the initiation of collision between India and Asia has stood up well (41)(42)(43) and is supported, for example, by field studies in northwest Pakistan, where the suture and Indian craton were overlapped by shallow-marine strata of latest Early Eocene age (Zone P9), showing that suturing was largely completed by Ϸ49 Ma (44). Evidence of subduction and final collision derives also from the occurrence of island arc volcanics and related intrusives, and massive calc-alkaline plutonism associated with the last major pulse dated at Ϸ50 Ma in the Ladakh Himalayas, for example (45)(46)(47).…”

Section: Drift Of India and Collision With Eurasiamentioning

confidence: 99%

Equatorial convergence of India and early Cenozoic climate trends

Kent

Muttoni

2008

Proc. Natl. Acad. Sci. U.S.A.

143

108

View full text Add to dashboard Cite

India's northward flight and collision with Asia was a major driver of global tectonics in the Cenozoic and, we argue, of atmospheric CO 2 concentration (pCO2) and thus global climate. Subduction of Tethyan oceanic crust with a carpet of carbonate-rich pelagic sediments deposited during transit beneath the high-productivity equatorial belt resulted in a component flux of CO 2 delivery to the atmosphere capable to maintain high pCO 2 levels and warm climate conditions until the decarbonation factory shut down with the collision of Greater India with Asia at the Early Eocene climatic optimum at Ϸ50 Ma. At about this time, the India continent and the highly weatherable Deccan Traps drifted into the equatorial humid belt where uptake of CO 2 by efficient silicate weathering further perturbed the delicate equilibrium between CO 2 input to and removal from the atmosphere toward progressively lower pCO 2 levels, thus marking the onset of a cooling trend over the Middle and Late Eocene that some suggest triggered the rapid expansion of Antarctic ice sheets at around the Eocene-Oligocene boundary.CO2 ͉ Deccan ͉ Tethys ͉ Himalaya ͉ Eocene M odern-day glacial climate, characterized by polar ice at sea level, is the long-term cooling derivative of a Cretaceousearly Cenozoic world dominated by warm conditions and the general absence of ice sheets (1, 2). The zenith of global warmth in the Cenozoic (0-65 Ma) was reached at Ϸ50 Ma during the Early Eocene climatic optimum (EECO) as the culmination of a Late Paleocene-Early Eocene (Ϸ60-50 Ma) warming trend in oceanic bottom waters (3) (Fig. 1A). The EECO was characterized by the widespread occurrence of cherts (4) (Fig. 1B) and reflected in warm climate conditions at even extreme high latitudes (5, 6). A persistent cooling trend ensued over the Middle and Late Eocene that eventually plummeted into a glacial climate mode with the inception of major Antarctic ice sheets at Oi-1 near the Eocene-Oligocene boundary at Ϸ34 Ma (7). Changes in ocean circulation and heat transport related to the opening of Southern Ocean gateways (8) occurred well after the start of the cooling trend at Ϸ50 Ma and do not seem to adequately account for inception of Antarctic glaciation according to recent climate models (e.g., refs. 9 and 10). Instead, reduction in greenhouse gas concentrations is the more likely fundamental cause of Antarctic freezing and global cooling (10). This is supported by the occurrence of high (albeit highly scattered) pCO 2 estimated values of Ͼ1,000 ppm at around the EECO (e.g., 11, 12; see also ref. 13) and generally low (Ͻ500 ppm) pCO 2 estimated values after Oi-1 that followed a decline that more or less parallels the long-term temperature record (14, 15) (Fig. 1 A). However, what triggered the global cooling from the EECO to Oi-1 (and thus the cause of the long-term decrease in pCO 2 ) is unclear (16).The BLAG model (17, 18) postulates that long-term changes in pCO 2 and resulting climate were driven primarily by variations in mantle outgassing tied to global seafloor prod...

show abstract

“…The leucogranites are typical Miocene Greater Himalayan leucogranites [Gansser, 1983;Edwards et al, 1999;Hodges, 2000] and form major plutons, like the Khula-Kangri Pluton, the Monlokarchung-Pasalum Pluton, and the Gophu-La Pluton west and south of the study area (Figure 1).…”

Section: Tc3001mentioning

confidence: 99%

“…[3] It is generally recognized that the Himalayan orogen grew along south directed and southward propagating crustal-scale thrust imbricates since the Eocene [e.g., Le Fort, 1975;Searle et al, 1987;Dewey et al, 1988;Hodges, 2000, and references cited therein; Stüwe and Foster, 2001]. Today about 80% of recent convergence between the Indian and Asian crustal plates are taken up mainly by thrusting kinematics in an orogen-normal direction along the Himalayan frontal thrust Jackson and Bilham, 1994].…”

Section: Introductionmentioning

confidence: 99%

Active tectonics in Eastern Lunana (NW Bhutan): Implications for the seismic and glacial hazard potential of the Bhutan Himalaya

Meyer

Wiesmayr

Brauner³

et al. 2006

Tectonics

View full text Add to dashboard Cite

Paleoseismological investigations, brittle fault analysis, and paleostrain calculations combined with the interpretation of satellite imagery and flood wave modeling were used to investigate the seismic and associated glacial hazard potential in Eastern Lunana, a remote area in NW Bhutan. Seismically induced liquefaction features, cracked pebbles, and a surface rupture of about 6.8 km length constrain the occurrence of M ≥ 6 earthquakes within this high‐altitude periglacial environment, which are the strongest earthquakes ever been reported for the Kingdom of Bhutan. Seismicity occurs along conjugate sets of faults trending NE‐SW to NNW‐SSE by strike‐slip and normal faulting mechanism indicating E‐W extension and N‐S shortening. The strain field for these conjugate sets of active faults is consistent with widespread observations of young E‐W expansion throughout southern Tibet and the north Himalaya. We expect, however, that N‐S trending active strike‐slip faults may even reach much farther to the south, at least into southern Bhutan. Numerous glacial lakes exist in the investigation area, and today more than 100 × 106 m3 of water are stored in moraine‐dammed and supraglacial lakes which are crosscut by active faults. Strong earthquakes may trigger glacial lake outburst floods, and the impact of such flash floods may be worst 80 km downstream where the valley is broad and densely populated. Consequently, tectonic models of active deformation have to be closely linked with glacial hazard evaluation and require rethinking and modification.

show abstract

Tectonics of the Himalaya and southern Tibet from two perspectives

Cited by 1,080 publications

References 227 publications

Crustal–lithospheric structure and continental extrusion of Tibet

Crustal–lithospheric structure and continental extrusion of Tibet

Equatorial convergence of India and early Cenozoic climate trends

Active tectonics in Eastern Lunana (NW Bhutan): Implications for the seismic and glacial hazard potential of the Bhutan Himalaya

Contact Info

Product

Resources

About