JinGen Dai | China University of Geosciences(Wuhan) (original) (raw)

Papers by JinGen Dai

Geophysical Research Letters

This article has been accepted for publication and undergone full peer review but has not been th... more This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as

Journal of Asian Earth Sciences

Geoscience Frontiers, 2016

Acta Geologica Sinica - English Edition, 2015

Tectonophysics, 2013

To understand the magmatic and tectonic events in the Eastern Kunlun Range, we conducted systemat... more To understand the magmatic and tectonic events in the Eastern Kunlun Range, we conducted systematic zircon U-Pb geochronology, and paired zircon (ZHe) and apatite (AHe) (U-Th)/He themchronology investigations in the central and eastern segments of this range. Zircon U-Pb ages show two-stage magmatic events of Late Silurian and latest Permian-Early Jurassic. ZHe and AHe ages and multi-system thermochronometers reveal multi-stage rapid cooling events. From a combination of these data with previously published geochronological and thermochronological ages, and regional geological setting, we confirm several important Phanerozoic tectono-magmatic events in this region. Whereas the Silurian granites might be related to a small paleo-ocean subduction and subsequent collision, the latest Permian-Early Triassic granitoids were produced by northward subduction of the Songpan-Ganzi Paleo-Tethyan ocean. The Late Triassic-earliest Jurassic granitoids and Late Triassic-Early Jurassic exhumation are interpreted as response to the collision between Kunlun-Qaidam and Qiangtang. Samples close to the Kunlun Fault show rapid Late Oligocene-Early Miocene exhumation (1.3-1.6 km/Ma), whereas those from the northern part of central segment display extremely low exhumation rates (0.02-0.05 km/Ma). This heterogeneous denudation during 30-20 Ma between northern and southern part of the central segment requires that crustal thickening was completed by lower-crustal underthrusting with little exhumation or crustal thickening in pre-Cenozoic times. The activity of the Kunlun Fault and associated normal faulting component were probably responsible for this stage of rapid exhumation in the southern part. The complex tectono-magmatic evolution of the Eastern Kunlun Range is controlled by pre-Cenozoic paleo-ocean subductions and subsequent continent collisions and Paleogene India-Asia collision.

Lithos, 2015

ABSTRACT The history of volcanic activity of the Gangdese arc in southern Tibet during the Cretac... more ABSTRACT The history of volcanic activity of the Gangdese arc in southern Tibet during the Cretaceous remains poorly known due to the intense erosion of the arc. Here we present zircon U-Pb ages, trace element and Hf isotopic data of tuffs and volcanic conglomerates from the Chongdoi and the Ngamring Formation in the Xigaze forearc basin. Three tuff samples from the Chongdoi Formation yield zircon U-Pb ages around 112 Ma. Such ages could be taken as their depositional ages, indicating that detrital clasts of the Chongdoi Formation were deposited at that time. One andesitic conglomerate sample from the Ngamring Formation was dated at ca. 105 Ma, the other rhyolitic conglomerate sample and one tuff sample were dated to be ca. 95 Ma and 91 Ma, respectively, suggesting that this formation was formed during the late Albian-late Turonian. All zircons illustrate I-type granitoid characteristics and possess low Ti-in-zircon temperatures (< 800 °C). Zircon εHf(t) values of tuffs from the Chongdoi Formation define two groups: (1) the first group of 117-110 Ma displays large positive εHf(t) values (+ 12.1 to + 17.1), larger than those of the tuff from the Ngamring Formation (+ 6.0 to + 10.2); (2) the second group of 119-111 Ma yields negative to small positive εHf(t) values (-4.5 to + 1.1). All above observations indicate that their host rocks were derived from the juvenile materials with significant input of fluids. Combined with extant data, the first group and the tuff, volcanic conglomerates from the Ngamring Formation are mostly likely derived from the eroded Cretaceous volcanic rocks in the Gangdese arc, while the second group is likely sourced from the late Early Cretaceous volcanic rocks in the central Lhasa terrane. Our data confirm the presence of Cretaceous volcanism in the Gangdese arc, suggesting that the Neo-Tethyan Ocean lithosphere was most likely subducted northerly in a normal angle rather than in a manner of low-angle subduction.

The Journal of Geology, 2013

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, a... more JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact

Lithos, 2013

The Cretaceous Xigaze ophiolite is best exposed at the central Yarlung Zangbo Suture Zone (YZSZ, ... more The Cretaceous Xigaze ophiolite is best exposed at the central Yarlung Zangbo Suture Zone (YZSZ, Tibet) which also includes the Gangdese arc and the Xigaze forearc basin. This study reports new geochronological and geochemical data for this ophiolite to revisit its geodynamic and petrogenetic evolution. The Xigaze peridotites have low CaO and Al 2 O 3 contents and U-shaped Rare Earth Element (REE) patterns, suggesting that they are residues after moderate to high degrees of partial melting and were modified by infiltration of Light Rare Earth Element (LREE)-enriched boninitic melts. The Xigaze crustal rocks belong to two groups: Mid-Ocean Ridge Basalt (MORB)-like rocks and boninitic rocks showing a uniform LREE depletion and flat to LREE enrichment on chondrite-normalized patterns, respectively. Geochemically, both groups show the influence of subducting oceanic slab-derived fluids. LA-ICPMS zircon U-Pb and Lu-Hf analyses from dolerite and quartz diorite dikes, which intruded into the mantle peridotite, and dolerite sheeted sills show that they were generated between 127 and 124 Ma. The zircons possess positive ε Hf (t) values ranging from +7.5 to + 17.3. Taking into account the geological and geochronological characteristics of the central-western YZSZ, we propose that ophiolites in this region formed in a forearc spreading setting through rapid slab rollback during subduction initiation between 130 and 120 Ma. Following this stage of spreading, the forearc was stabilized and the zone of melting migrated beneath the Gangdese arc producing the voluminous Late Cretaceous granitoids displaying depleted mantle-type Hf isotopic compositions. Our model provides a new explanation for the generation and evolution of forearc-type ophiolites.

Lithos, 2011

The Yarlung Zangbo Suture Zone (YZSZ), southern Tibet, is a discontinuous belt that is more than ... more The Yarlung Zangbo Suture Zone (YZSZ), southern Tibet, is a discontinuous belt that is more than 2000 km long, composed of the remnants of Neo-Tethyan Mesozoic ocean. One of these relicts is the Xiugugabu ophiolitic massif which is a mantle thrust sheet of more than 260 km 2 overlying the Cretaceous tectonic mélange south of the YZSZ in SW Tibet. The massif is composed of harzburgites and clinopyroxeneharzburgites with porphyroclastic and porphyromylonitic textures. In the southern part of the massif, peridotites were intruded by amphibole-bearing microgabbro and microgabbronorite sills. A diabase unit which is overlaid by a sedimentary sequence crops out on the NE flank of the massif. Mineral chemistry in harzburgites and clinopyroxene-harzburgites indicates compositions similar to abyssal and forearc peridotites. Peridotites are slightly LREE depleted to enriched with [La/Yb] CN 0.06-2.8 and [La/ Sm] CN 0.34-2.64. These ultramafic rocks are inferred to be the residues of 5-25% of partial melting of a depleted mantle that has been enriched by percolating metasomatic melts in a suprasubduction environment. Amphibole-microgabbro and amphibole-microgabbronorite sills are mostly composed of brown to green amphibole, calcic plagioclase, clinopyroxene, ilmenite and orthopyroxene in gabbronorite. Textures and compositions of the brown amphiboles indicate a near-solidus high temperature hydrothermal origin (N 800°C). These intrusive rocks are tholeiitic and show N-MORB type REE patterns ([La/Yb] NC 0.35-0.90), a LILE (mainly Th) enrichment and noticeable Nb, Ta and Ti negative anomalies. They have a suprasubduction affinity and were formed in a back-arc basin setting. The diabase unit outcropping to the NE of the massif is not directly related to the ultramafic and mafic ophiolitic rocks. The diabase shows LREE enriched patterns ([La/Yb] NC 8-8.9) and slight Nb, Ta and Ti negative anomalies. The diabase has an intraplate affinity and could have been derived from a mantle source enriched by subduction-related fluids. The absence of continental crustal assimilation indicates that these rocks were probably emplaced in the Jurassic, in an oceanic environment after the Triassic disaggregation of the Indian plate. The data are consistent with the recent geodynamic model proposed for the central part of the suture for the closure of the Neo-Tethys and suggest that the geodynamic evolution of the western part of the basin was comparable to the central part.

Lithos, 2013

Major and trace element, Sr-Nd-Pb and zircon U-Pb and Hf isotope data are presented for the newly... more Major and trace element, Sr-Nd-Pb and zircon U-Pb and Hf isotope data are presented for the newly discovered Abushan volcanic rocks in the southern Qiangtang Terrane, central Tibet. These results offer new insights into the evolution of the Tibetan plateau during Cretaceous. The Abushan volcanic rocks are composed mainly of andesites and trachy-andesites. Zircon U-Pb dating constrains the timing of emplacement as Late Cretaceous (79.9 ± 2.7-75.9 ± 0.49 Ma). Major element geochemistry shows that the Abushan volcanic rocks belong to high-K calc-alkaline series. All the andesites and trachy-andesites are enriched in large ion lithophile elements (LILE) and light rare earth elements (LREE), and depleted in high field strength elements (HFSE) and heavy rare earth elements (HREE). The geochemical features and ages of the Abushan volcanic rocks relate them with post-collisional setting. Furthermore, the volcanic rocks display negative ε Nd (t) (− 3.1 to − 2.5), relatively constant 87 Sr/ 86 Sr ratios (0.70614-0.70735) and negative ε Hf (t) values (− 5.8 to − 2.1). The Sr-Nd-Pb and Hf isotope signature suggests that the andesites and trachy-andesites were derived from the anatexis of mafic lower crust by intrusion or underplating of mantle-derived basaltic magma. The petrogenesis of Abushan andesites provides robust evidence for the crustal thickening, delamination and early uplifting of central Tibet during Late Cretaceous.

Journal of the Geological Society, 2013

The central Songpan-Ganzi belt, located on the eastern margin of the Tibetan Plateau, has a simil... more The central Songpan-Ganzi belt, located on the eastern margin of the Tibetan Plateau, has a similar high elevation and low relief to parts of central Tibet. Thermochronological studies from the central Tibetan Plateau reveal a history of slow exhumation (rates <0.05 km Ma −1) since 45 Ma; however, the exhumation history of the central Songpan-Ganzi belt is unknown. To address this, we conducted an apatite and zircon (U-Th)/He thermochronology study of bedrock samples collected across the central Songpan-Ganzi belt and into central parts of the Tibetan Plateau. Zircon (U-Th)/He ages range from 54.2 ± 7.5 to 146.5 ± 10.0 Ma and the majority of apatite (U-Th)/He ages fall between 74.7 ± 19.0 and 35.7 ± 9.4 Ma. Thermal history models of these data show rapid cooling in the late Mesozoic and much slower cooling diagnostic of low rates of erosion throughout most of the Cenozoic. The late Mesozoic rapid cooling is consistent with the existence of significant topography and relief at least in some parts of the Songpan-Ganzi belt at that time. We find no evidence for a regional Miocene acceleration in erosion, although three samples from the headwaters of the Salween and Mekong rivers gave younger AHe ages between 15 and 16 Ma that reflect an acceleration in river incision. Supplementary material: Laser ablation-inductively coupled plasma mass spectrometry zircon U-Pb data from central and eastern Tibet are available at www.geolsoc.org.uk/SUP18647.

Journal of Asian Earth Sciences, 2012

Gondwana Research, 2012

The surface uplift of the Tibetan Plateau is the key boundary condition in many Cenozoic geologic... more The surface uplift of the Tibetan Plateau is the key boundary condition in many Cenozoic geological events ranging from global cooling to changes of Asian environments during Cenozoic. However, poorly constrained timing for the uplift of Tibetan Plateau makes these interpretations highly debatable. Here we report results from sedimentology, detrital zircon U-Pb and Lu-Hf isotopic compositions, and paleomagnetic signatures from both the eastern and western Hoh Xil basins of north-central Tibetan Plateau. Sedimentary lithofacies and facies associations analyzed in the western Hoh Xil basin indicate they were deposited in a braided fluvial system and alluvial fan, similar with the Fenghuoshan Group, eastern Hoh Xil basin. Provenance analyses from conglomerate clast compositions, paleocurrent orientations, and detrital zircon U-Pb and Lu-Hf isotopic compositions document sediments in both western and eastern basins were derived from the Qiangtang and Lhasa blocks. These observations, in combination with comparative paleomagnetic results, imply that Hoh Xil basin was a single, wide basin during Paleogene. The period of Hoh Xil basin deposition was coeval with significant period of the early Cenozoic uplift and erosion of the Qiangtang and Lhasa blocks. These observations not only reinforce the suggestion that the Qiangtang and Lhasa blocks were uplifted during Eocene to form a proto-Tibetan Plateau, but also imply that the proto-Tibet Plateau is vast in areal extent. The large dimension and high elevation of the proto-Tibetan Plateau probably contributed to the global cooling during the early Eocene.

Geophysical Research Letters

This article has been accepted for publication and undergone full peer review but has not been th... more This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as

Journal of Asian Earth Sciences

Geoscience Frontiers, 2016

Acta Geologica Sinica - English Edition, 2015

Tectonophysics, 2013

To understand the magmatic and tectonic events in the Eastern Kunlun Range, we conducted systemat... more To understand the magmatic and tectonic events in the Eastern Kunlun Range, we conducted systematic zircon U-Pb geochronology, and paired zircon (ZHe) and apatite (AHe) (U-Th)/He themchronology investigations in the central and eastern segments of this range. Zircon U-Pb ages show two-stage magmatic events of Late Silurian and latest Permian-Early Jurassic. ZHe and AHe ages and multi-system thermochronometers reveal multi-stage rapid cooling events. From a combination of these data with previously published geochronological and thermochronological ages, and regional geological setting, we confirm several important Phanerozoic tectono-magmatic events in this region. Whereas the Silurian granites might be related to a small paleo-ocean subduction and subsequent collision, the latest Permian-Early Triassic granitoids were produced by northward subduction of the Songpan-Ganzi Paleo-Tethyan ocean. The Late Triassic-earliest Jurassic granitoids and Late Triassic-Early Jurassic exhumation are interpreted as response to the collision between Kunlun-Qaidam and Qiangtang. Samples close to the Kunlun Fault show rapid Late Oligocene-Early Miocene exhumation (1.3-1.6 km/Ma), whereas those from the northern part of central segment display extremely low exhumation rates (0.02-0.05 km/Ma). This heterogeneous denudation during 30-20 Ma between northern and southern part of the central segment requires that crustal thickening was completed by lower-crustal underthrusting with little exhumation or crustal thickening in pre-Cenozoic times. The activity of the Kunlun Fault and associated normal faulting component were probably responsible for this stage of rapid exhumation in the southern part. The complex tectono-magmatic evolution of the Eastern Kunlun Range is controlled by pre-Cenozoic paleo-ocean subductions and subsequent continent collisions and Paleogene India-Asia collision.

Lithos, 2015

ABSTRACT The history of volcanic activity of the Gangdese arc in southern Tibet during the Cretac... more ABSTRACT The history of volcanic activity of the Gangdese arc in southern Tibet during the Cretaceous remains poorly known due to the intense erosion of the arc. Here we present zircon U-Pb ages, trace element and Hf isotopic data of tuffs and volcanic conglomerates from the Chongdoi and the Ngamring Formation in the Xigaze forearc basin. Three tuff samples from the Chongdoi Formation yield zircon U-Pb ages around 112 Ma. Such ages could be taken as their depositional ages, indicating that detrital clasts of the Chongdoi Formation were deposited at that time. One andesitic conglomerate sample from the Ngamring Formation was dated at ca. 105 Ma, the other rhyolitic conglomerate sample and one tuff sample were dated to be ca. 95 Ma and 91 Ma, respectively, suggesting that this formation was formed during the late Albian-late Turonian. All zircons illustrate I-type granitoid characteristics and possess low Ti-in-zircon temperatures (&lt; 800 °C). Zircon εHf(t) values of tuffs from the Chongdoi Formation define two groups: (1) the first group of 117-110 Ma displays large positive εHf(t) values (+ 12.1 to + 17.1), larger than those of the tuff from the Ngamring Formation (+ 6.0 to + 10.2); (2) the second group of 119-111 Ma yields negative to small positive εHf(t) values (-4.5 to + 1.1). All above observations indicate that their host rocks were derived from the juvenile materials with significant input of fluids. Combined with extant data, the first group and the tuff, volcanic conglomerates from the Ngamring Formation are mostly likely derived from the eroded Cretaceous volcanic rocks in the Gangdese arc, while the second group is likely sourced from the late Early Cretaceous volcanic rocks in the central Lhasa terrane. Our data confirm the presence of Cretaceous volcanism in the Gangdese arc, suggesting that the Neo-Tethyan Ocean lithosphere was most likely subducted northerly in a normal angle rather than in a manner of low-angle subduction.

The Journal of Geology, 2013

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, a... more JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact

Lithos, 2013

The Cretaceous Xigaze ophiolite is best exposed at the central Yarlung Zangbo Suture Zone (YZSZ, ... more The Cretaceous Xigaze ophiolite is best exposed at the central Yarlung Zangbo Suture Zone (YZSZ, Tibet) which also includes the Gangdese arc and the Xigaze forearc basin. This study reports new geochronological and geochemical data for this ophiolite to revisit its geodynamic and petrogenetic evolution. The Xigaze peridotites have low CaO and Al 2 O 3 contents and U-shaped Rare Earth Element (REE) patterns, suggesting that they are residues after moderate to high degrees of partial melting and were modified by infiltration of Light Rare Earth Element (LREE)-enriched boninitic melts. The Xigaze crustal rocks belong to two groups: Mid-Ocean Ridge Basalt (MORB)-like rocks and boninitic rocks showing a uniform LREE depletion and flat to LREE enrichment on chondrite-normalized patterns, respectively. Geochemically, both groups show the influence of subducting oceanic slab-derived fluids. LA-ICPMS zircon U-Pb and Lu-Hf analyses from dolerite and quartz diorite dikes, which intruded into the mantle peridotite, and dolerite sheeted sills show that they were generated between 127 and 124 Ma. The zircons possess positive ε Hf (t) values ranging from +7.5 to + 17.3. Taking into account the geological and geochronological characteristics of the central-western YZSZ, we propose that ophiolites in this region formed in a forearc spreading setting through rapid slab rollback during subduction initiation between 130 and 120 Ma. Following this stage of spreading, the forearc was stabilized and the zone of melting migrated beneath the Gangdese arc producing the voluminous Late Cretaceous granitoids displaying depleted mantle-type Hf isotopic compositions. Our model provides a new explanation for the generation and evolution of forearc-type ophiolites.

Lithos, 2011

The Yarlung Zangbo Suture Zone (YZSZ), southern Tibet, is a discontinuous belt that is more than ... more The Yarlung Zangbo Suture Zone (YZSZ), southern Tibet, is a discontinuous belt that is more than 2000 km long, composed of the remnants of Neo-Tethyan Mesozoic ocean. One of these relicts is the Xiugugabu ophiolitic massif which is a mantle thrust sheet of more than 260 km 2 overlying the Cretaceous tectonic mélange south of the YZSZ in SW Tibet. The massif is composed of harzburgites and clinopyroxeneharzburgites with porphyroclastic and porphyromylonitic textures. In the southern part of the massif, peridotites were intruded by amphibole-bearing microgabbro and microgabbronorite sills. A diabase unit which is overlaid by a sedimentary sequence crops out on the NE flank of the massif. Mineral chemistry in harzburgites and clinopyroxene-harzburgites indicates compositions similar to abyssal and forearc peridotites. Peridotites are slightly LREE depleted to enriched with [La/Yb] CN 0.06-2.8 and [La/ Sm] CN 0.34-2.64. These ultramafic rocks are inferred to be the residues of 5-25% of partial melting of a depleted mantle that has been enriched by percolating metasomatic melts in a suprasubduction environment. Amphibole-microgabbro and amphibole-microgabbronorite sills are mostly composed of brown to green amphibole, calcic plagioclase, clinopyroxene, ilmenite and orthopyroxene in gabbronorite. Textures and compositions of the brown amphiboles indicate a near-solidus high temperature hydrothermal origin (N 800°C). These intrusive rocks are tholeiitic and show N-MORB type REE patterns ([La/Yb] NC 0.35-0.90), a LILE (mainly Th) enrichment and noticeable Nb, Ta and Ti negative anomalies. They have a suprasubduction affinity and were formed in a back-arc basin setting. The diabase unit outcropping to the NE of the massif is not directly related to the ultramafic and mafic ophiolitic rocks. The diabase shows LREE enriched patterns ([La/Yb] NC 8-8.9) and slight Nb, Ta and Ti negative anomalies. The diabase has an intraplate affinity and could have been derived from a mantle source enriched by subduction-related fluids. The absence of continental crustal assimilation indicates that these rocks were probably emplaced in the Jurassic, in an oceanic environment after the Triassic disaggregation of the Indian plate. The data are consistent with the recent geodynamic model proposed for the central part of the suture for the closure of the Neo-Tethys and suggest that the geodynamic evolution of the western part of the basin was comparable to the central part.

Lithos, 2013

Major and trace element, Sr-Nd-Pb and zircon U-Pb and Hf isotope data are presented for the newly... more Major and trace element, Sr-Nd-Pb and zircon U-Pb and Hf isotope data are presented for the newly discovered Abushan volcanic rocks in the southern Qiangtang Terrane, central Tibet. These results offer new insights into the evolution of the Tibetan plateau during Cretaceous. The Abushan volcanic rocks are composed mainly of andesites and trachy-andesites. Zircon U-Pb dating constrains the timing of emplacement as Late Cretaceous (79.9 ± 2.7-75.9 ± 0.49 Ma). Major element geochemistry shows that the Abushan volcanic rocks belong to high-K calc-alkaline series. All the andesites and trachy-andesites are enriched in large ion lithophile elements (LILE) and light rare earth elements (LREE), and depleted in high field strength elements (HFSE) and heavy rare earth elements (HREE). The geochemical features and ages of the Abushan volcanic rocks relate them with post-collisional setting. Furthermore, the volcanic rocks display negative ε Nd (t) (− 3.1 to − 2.5), relatively constant 87 Sr/ 86 Sr ratios (0.70614-0.70735) and negative ε Hf (t) values (− 5.8 to − 2.1). The Sr-Nd-Pb and Hf isotope signature suggests that the andesites and trachy-andesites were derived from the anatexis of mafic lower crust by intrusion or underplating of mantle-derived basaltic magma. The petrogenesis of Abushan andesites provides robust evidence for the crustal thickening, delamination and early uplifting of central Tibet during Late Cretaceous.

Journal of the Geological Society, 2013

The central Songpan-Ganzi belt, located on the eastern margin of the Tibetan Plateau, has a simil... more The central Songpan-Ganzi belt, located on the eastern margin of the Tibetan Plateau, has a similar high elevation and low relief to parts of central Tibet. Thermochronological studies from the central Tibetan Plateau reveal a history of slow exhumation (rates <0.05 km Ma −1) since 45 Ma; however, the exhumation history of the central Songpan-Ganzi belt is unknown. To address this, we conducted an apatite and zircon (U-Th)/He thermochronology study of bedrock samples collected across the central Songpan-Ganzi belt and into central parts of the Tibetan Plateau. Zircon (U-Th)/He ages range from 54.2 ± 7.5 to 146.5 ± 10.0 Ma and the majority of apatite (U-Th)/He ages fall between 74.7 ± 19.0 and 35.7 ± 9.4 Ma. Thermal history models of these data show rapid cooling in the late Mesozoic and much slower cooling diagnostic of low rates of erosion throughout most of the Cenozoic. The late Mesozoic rapid cooling is consistent with the existence of significant topography and relief at least in some parts of the Songpan-Ganzi belt at that time. We find no evidence for a regional Miocene acceleration in erosion, although three samples from the headwaters of the Salween and Mekong rivers gave younger AHe ages between 15 and 16 Ma that reflect an acceleration in river incision. Supplementary material: Laser ablation-inductively coupled plasma mass spectrometry zircon U-Pb data from central and eastern Tibet are available at www.geolsoc.org.uk/SUP18647.

Journal of Asian Earth Sciences, 2012

Gondwana Research, 2012

The surface uplift of the Tibetan Plateau is the key boundary condition in many Cenozoic geologic... more The surface uplift of the Tibetan Plateau is the key boundary condition in many Cenozoic geological events ranging from global cooling to changes of Asian environments during Cenozoic. However, poorly constrained timing for the uplift of Tibetan Plateau makes these interpretations highly debatable. Here we report results from sedimentology, detrital zircon U-Pb and Lu-Hf isotopic compositions, and paleomagnetic signatures from both the eastern and western Hoh Xil basins of north-central Tibetan Plateau. Sedimentary lithofacies and facies associations analyzed in the western Hoh Xil basin indicate they were deposited in a braided fluvial system and alluvial fan, similar with the Fenghuoshan Group, eastern Hoh Xil basin. Provenance analyses from conglomerate clast compositions, paleocurrent orientations, and detrital zircon U-Pb and Lu-Hf isotopic compositions document sediments in both western and eastern basins were derived from the Qiangtang and Lhasa blocks. These observations, in combination with comparative paleomagnetic results, imply that Hoh Xil basin was a single, wide basin during Paleogene. The period of Hoh Xil basin deposition was coeval with significant period of the early Cenozoic uplift and erosion of the Qiangtang and Lhasa blocks. These observations not only reinforce the suggestion that the Qiangtang and Lhasa blocks were uplifted during Eocene to form a proto-Tibetan Plateau, but also imply that the proto-Tibet Plateau is vast in areal extent. The large dimension and high elevation of the proto-Tibetan Plateau probably contributed to the global cooling during the early Eocene.