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Xiaomin Fang - One of the best experts on this subject based on the ideXlab platform.

  • Paleolake salinity evolution in the Qaidam Basin (NE Tibetan Plateau) between ~42 and 29 Ma: Links to Global Cooling and Paratethys sea incursions
    2021
    Co-Authors: Yibo Yang, Xiaomin Fang, Weilin Zhang, Chunhui Song, Rongsheng Yang
    Abstract:

    <p>Global Cooling, the early uplift of the Tibetan Plateau, and the retreat of the Paratethys are three main factors that regulate long-term climate change in the Asian interior during the Cenozoic. However, the debated elevation history of the Tibetan Plateau and the overlapping climate effects of the Tibetan Plateau uplift and Paratethys retreat makes it difficult to assess the driving mechanism on regional climate change in a particular period. Some recent progress suggests that precisely dated Paratethys transgression/regression cycles appear to have fluctuated over broad regions with low relief in the northern Tibetan Plateau in the middle Eocene–early Oligocene, when the Global climate was characterized by generally continuous Cooling followed by the rapid Eocene–Oligocene climate transition (EOT). Therefore, a middle Eocene–early Oligocene record from the Asian interior with unambiguous paleoclimatic implications offers an opportunity to distinguish between the climatic effects of the Paratethys retreat and those of Global Cooling.</p><p>Here, we present a complete paleolake salinity record from middle Eocene to early Miocene (~42-29 Ma) in the Qaidam Basin using detailed clay boron content and clay mineralogical investigations. Two independent paleosalimeters, equivalent boron and Couch’s salinity, collectively present a three-staged salinity evolution, from an oligohaline–mesohaline environment in the middle Eocene (42-~34 Ma) to a mesosaline environment in late Eocene-early Oligocene (~34-~29 Ma). This clay boron-derived salinity evolution is further supported by the published chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin resembles the hydroclimate change in the neighboring Xining Basin, of which both present good agreement with changes of marine benthic oxygen isotope compositions. We thus speculated that the secular trend of clay boron-derived paleolake salinity in ~42-29 Ma is primarily controlled by Global Cooling, which regulates regional climate change by influencing the evaporation capacity in the moisture source of Qaidam Basin. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.</p>

  • paleolake salinity evolution in the qaidam basin ne tibetan plateau between 42 and 29 ma links to Global Cooling and paratethys sea incursions
    Sedimentary Geology, 2020
    Co-Authors: Yibo Yang, Xiaomin Fang, Weilin Zhang, Chunhui Song, Rongsheng Yang
    Abstract:

    Abstract Climate change in the Asian interior during the early Cenozoic remains poorly constrained due to difficulties in distinguishing the impacts of Global Cooling, the early uplift of the Tibetan Plateau and the retreat of the Paratethys. A quantitative estimation of paleolake salinity enables a better understanding of the regional hydrological cycle and contemporaneous climate change. Here, we present a quantitative record of paleolake salinity in the Qaidam Basin between ~42 and 29 Ma using detailed mineralogical investigations and clay boron content data. This paleolake salinity record generally covers a tectonically less active period in the Asian interior characterized by continuous Global Cooling, the abrupt Eocene–Oligocene climate transition and the Paratethys transgression/regression cycles, thus offering an opportunity to explore the roles of Global Cooling and the Paratethys retreat in regulating the regional hydrological cycle. The results of two boron-derived paleosalimeters, equivalent boron and Couch's salinity, collectively indicate a two-stage paleolake salinity evolution, from an oligohaline–mesohaline environment in the middle–late Eocene (~42–~34 Ma) to a mesosaline environment in the early Oligocene (~34–~29 Ma). This transition is also supported by qualitative chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin yields a generally good match with the hydroclimate change in the neighboring Xining Basin, thus indicating a comparable regional drying trend. The synchronous changes in quantitative paleolake salinity and silicate weathering processes derived from the illite weathering index and chlorite content in the studied section suggest climate control of silicate weathering. Global Cooling is speculated to have been the first-order driving factor in regulating long-term climatic evolution and weathering responses in the Asian interior between ~42 and 29 Ma. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.

  • Paleolake salinity evolution in the Qaidam Basin (NE Tibetan Plateau) between ~42 and 29 Ma: Links to Global Cooling and Paratethys sea incursions
    Sedimentary Geology, 2020
    Co-Authors: Yibo Yang, Xiaomin Fang, Weilin Zhang, Chunhui Song, Rongsheng Yang
    Abstract:

    Abstract Climate change in the Asian interior during the early Cenozoic remains poorly constrained due to difficulties in distinguishing the impacts of Global Cooling, the early uplift of the Tibetan Plateau and the retreat of the Paratethys. A quantitative estimation of paleolake salinity enables a better understanding of the regional hydrological cycle and contemporaneous climate change. Here, we present a quantitative record of paleolake salinity in the Qaidam Basin between ~42 and 29 Ma using detailed mineralogical investigations and clay boron content data. This paleolake salinity record generally covers a tectonically less active period in the Asian interior characterized by continuous Global Cooling, the abrupt Eocene–Oligocene climate transition and the Paratethys transgression/regression cycles, thus offering an opportunity to explore the roles of Global Cooling and the Paratethys retreat in regulating the regional hydrological cycle. The results of two boron-derived paleosalimeters, equivalent boron and Couch's salinity, collectively indicate a two-stage paleolake salinity evolution, from an oligohaline–mesohaline environment in the middle–late Eocene (~42–~34 Ma) to a mesosaline environment in the early Oligocene (~34–~29 Ma). This transition is also supported by qualitative chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin yields a generally good match with the hydroclimate change in the neighboring Xining Basin, thus indicating a comparable regional drying trend. The synchronous changes in quantitative paleolake salinity and silicate weathering processes derived from the illite weathering index and chlorite content in the studied section suggest climate control of silicate weathering. Global Cooling is speculated to have been the first-order driving factor in regulating long-term climatic evolution and weathering responses in the Asian interior between ~42 and 29 Ma. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.

  • Paleogene Global Cooling–induced temperature feedback on chemical weathering, as recorded in the northern Tibetan Plateau
    Geology, 2019
    Co-Authors: Xiaomin Fang, Yibo Yang, Weilin Zhang, Albert Galy, Chunhui Song
    Abstract:

    Abstract Plate-tectonic processes have long been thought to be the major cause of the Cenozoic Global carbon cycle, and Global Cooling by uplift of the Tibetan Plateau through enhancing silicate weathering and organic carbon burial and/or by weathering of obducted ophiolites during the closure of the Neo-Tethys Ocean. However, the imbalance resulting from accelerated CO2 consumption and a relatively stable CO2 input from volcanic degassing during the Cenozoic should have depleted atmospheric CO2 within a few million years; therefore, a negative feedback mechanism must have stabilized the carbon cycle. Here, we present the first almost-complete Paleogene silicate weathering intensity (SWI) records from continental rocks in the northern Tibetan Plateau showing that silicate weathering in this tectonically inactive area was modulated by Global temperature. These findings suggest that Paleogene Global Cooling was also strongly influenced by a temperature feedback mechanism, which regulated silicate weathering rates and hydrological cycles and maintained a nearly stable carbon cycle. It acted as a negative feedback by decreasing CO2 consumption resulting from the lower SWI and the kinetic limitations in tectonically inactive areas.

  • an eocene miocene continuous rock magnetic record from the sediments in the xining basin nw china indication for cenozoic persistent drying driven by Global Cooling and tibetan plateau uplift
    Geophysical Journal International, 2015
    Co-Authors: Xiaomin Fang, Chunhui Song, Jinbo Zan, Erwin Appel, Shuang Dai, Shibo Tuo
    Abstract:

    Tibetan Plateau uplift and Global Cooling have generally been thought to have caused the drying of the Asian inland, but how and when these factors drove the aridification is unknown. The Xining Basin at the NE Tibetan Plateau received continuous Eocene-Miocene fine-grained sediments, providing an excellent opportunity to address this question. Here we present detailed rock magnetic and diffuse reflectance spectroscopy (DRS) analyses for a well-dated Cenozoic sedimentary record from the Xiejia section in the basin. Magnetic susceptibility (chi), saturation magnetization (Ms) and saturation isothermal remanent magnetization (SIRM) in this section show a long-term decreasing trend from similar to 52 to similar to 25 Ma, well coinciding with Global Cooling and drying in the region, and an increasing trend since similar to 25 Ma, which is in contrast to the further progressing aridification of the basin. Thermomagnetic results and DRS-determined hematite contents suggest that the relative content of magnetite and hematite is the main control on the chi, Ms and SIRM values. We argue that the long-term Eocene-Oligocene Global Cooling increased the drying of the Asian inland, lowering the lake level and exposing a larger area to low temperature oxidation for longer times, thus producing more hematite and leading to the decreasing trend of magnetic concentration parameters from similar to 52 to similar to 25 Ma. An intensive uplift of the NE Tibetan Plateau since similar to 25 Ma, associated with a change in the sedimentary source, might be responsible for the increase of chi, Ms and SIRM after 25 Ma.

Chunhui Song - One of the best experts on this subject based on the ideXlab platform.

  • Paleolake salinity evolution in the Qaidam Basin (NE Tibetan Plateau) between ~42 and 29 Ma: Links to Global Cooling and Paratethys sea incursions
    2021
    Co-Authors: Yibo Yang, Xiaomin Fang, Weilin Zhang, Chunhui Song, Rongsheng Yang
    Abstract:

    <p>Global Cooling, the early uplift of the Tibetan Plateau, and the retreat of the Paratethys are three main factors that regulate long-term climate change in the Asian interior during the Cenozoic. However, the debated elevation history of the Tibetan Plateau and the overlapping climate effects of the Tibetan Plateau uplift and Paratethys retreat makes it difficult to assess the driving mechanism on regional climate change in a particular period. Some recent progress suggests that precisely dated Paratethys transgression/regression cycles appear to have fluctuated over broad regions with low relief in the northern Tibetan Plateau in the middle Eocene–early Oligocene, when the Global climate was characterized by generally continuous Cooling followed by the rapid Eocene–Oligocene climate transition (EOT). Therefore, a middle Eocene–early Oligocene record from the Asian interior with unambiguous paleoclimatic implications offers an opportunity to distinguish between the climatic effects of the Paratethys retreat and those of Global Cooling.</p><p>Here, we present a complete paleolake salinity record from middle Eocene to early Miocene (~42-29 Ma) in the Qaidam Basin using detailed clay boron content and clay mineralogical investigations. Two independent paleosalimeters, equivalent boron and Couch’s salinity, collectively present a three-staged salinity evolution, from an oligohaline–mesohaline environment in the middle Eocene (42-~34 Ma) to a mesosaline environment in late Eocene-early Oligocene (~34-~29 Ma). This clay boron-derived salinity evolution is further supported by the published chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin resembles the hydroclimate change in the neighboring Xining Basin, of which both present good agreement with changes of marine benthic oxygen isotope compositions. We thus speculated that the secular trend of clay boron-derived paleolake salinity in ~42-29 Ma is primarily controlled by Global Cooling, which regulates regional climate change by influencing the evaporation capacity in the moisture source of Qaidam Basin. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.</p>

  • paleolake salinity evolution in the qaidam basin ne tibetan plateau between 42 and 29 ma links to Global Cooling and paratethys sea incursions
    Sedimentary Geology, 2020
    Co-Authors: Yibo Yang, Xiaomin Fang, Weilin Zhang, Chunhui Song, Rongsheng Yang
    Abstract:

    Abstract Climate change in the Asian interior during the early Cenozoic remains poorly constrained due to difficulties in distinguishing the impacts of Global Cooling, the early uplift of the Tibetan Plateau and the retreat of the Paratethys. A quantitative estimation of paleolake salinity enables a better understanding of the regional hydrological cycle and contemporaneous climate change. Here, we present a quantitative record of paleolake salinity in the Qaidam Basin between ~42 and 29 Ma using detailed mineralogical investigations and clay boron content data. This paleolake salinity record generally covers a tectonically less active period in the Asian interior characterized by continuous Global Cooling, the abrupt Eocene–Oligocene climate transition and the Paratethys transgression/regression cycles, thus offering an opportunity to explore the roles of Global Cooling and the Paratethys retreat in regulating the regional hydrological cycle. The results of two boron-derived paleosalimeters, equivalent boron and Couch's salinity, collectively indicate a two-stage paleolake salinity evolution, from an oligohaline–mesohaline environment in the middle–late Eocene (~42–~34 Ma) to a mesosaline environment in the early Oligocene (~34–~29 Ma). This transition is also supported by qualitative chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin yields a generally good match with the hydroclimate change in the neighboring Xining Basin, thus indicating a comparable regional drying trend. The synchronous changes in quantitative paleolake salinity and silicate weathering processes derived from the illite weathering index and chlorite content in the studied section suggest climate control of silicate weathering. Global Cooling is speculated to have been the first-order driving factor in regulating long-term climatic evolution and weathering responses in the Asian interior between ~42 and 29 Ma. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.

  • Paleolake salinity evolution in the Qaidam Basin (NE Tibetan Plateau) between ~42 and 29 Ma: Links to Global Cooling and Paratethys sea incursions
    Sedimentary Geology, 2020
    Co-Authors: Yibo Yang, Xiaomin Fang, Weilin Zhang, Chunhui Song, Rongsheng Yang
    Abstract:

    Abstract Climate change in the Asian interior during the early Cenozoic remains poorly constrained due to difficulties in distinguishing the impacts of Global Cooling, the early uplift of the Tibetan Plateau and the retreat of the Paratethys. A quantitative estimation of paleolake salinity enables a better understanding of the regional hydrological cycle and contemporaneous climate change. Here, we present a quantitative record of paleolake salinity in the Qaidam Basin between ~42 and 29 Ma using detailed mineralogical investigations and clay boron content data. This paleolake salinity record generally covers a tectonically less active period in the Asian interior characterized by continuous Global Cooling, the abrupt Eocene–Oligocene climate transition and the Paratethys transgression/regression cycles, thus offering an opportunity to explore the roles of Global Cooling and the Paratethys retreat in regulating the regional hydrological cycle. The results of two boron-derived paleosalimeters, equivalent boron and Couch's salinity, collectively indicate a two-stage paleolake salinity evolution, from an oligohaline–mesohaline environment in the middle–late Eocene (~42–~34 Ma) to a mesosaline environment in the early Oligocene (~34–~29 Ma). This transition is also supported by qualitative chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin yields a generally good match with the hydroclimate change in the neighboring Xining Basin, thus indicating a comparable regional drying trend. The synchronous changes in quantitative paleolake salinity and silicate weathering processes derived from the illite weathering index and chlorite content in the studied section suggest climate control of silicate weathering. Global Cooling is speculated to have been the first-order driving factor in regulating long-term climatic evolution and weathering responses in the Asian interior between ~42 and 29 Ma. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.

  • Paleogene Global Cooling–induced temperature feedback on chemical weathering, as recorded in the northern Tibetan Plateau
    Geology, 2019
    Co-Authors: Xiaomin Fang, Yibo Yang, Weilin Zhang, Albert Galy, Chunhui Song
    Abstract:

    Abstract Plate-tectonic processes have long been thought to be the major cause of the Cenozoic Global carbon cycle, and Global Cooling by uplift of the Tibetan Plateau through enhancing silicate weathering and organic carbon burial and/or by weathering of obducted ophiolites during the closure of the Neo-Tethys Ocean. However, the imbalance resulting from accelerated CO2 consumption and a relatively stable CO2 input from volcanic degassing during the Cenozoic should have depleted atmospheric CO2 within a few million years; therefore, a negative feedback mechanism must have stabilized the carbon cycle. Here, we present the first almost-complete Paleogene silicate weathering intensity (SWI) records from continental rocks in the northern Tibetan Plateau showing that silicate weathering in this tectonically inactive area was modulated by Global temperature. These findings suggest that Paleogene Global Cooling was also strongly influenced by a temperature feedback mechanism, which regulated silicate weathering rates and hydrological cycles and maintained a nearly stable carbon cycle. It acted as a negative feedback by decreasing CO2 consumption resulting from the lower SWI and the kinetic limitations in tectonically inactive areas.

  • an eocene miocene continuous rock magnetic record from the sediments in the xining basin nw china indication for cenozoic persistent drying driven by Global Cooling and tibetan plateau uplift
    Geophysical Journal International, 2015
    Co-Authors: Xiaomin Fang, Chunhui Song, Jinbo Zan, Erwin Appel, Shuang Dai, Shibo Tuo
    Abstract:

    Tibetan Plateau uplift and Global Cooling have generally been thought to have caused the drying of the Asian inland, but how and when these factors drove the aridification is unknown. The Xining Basin at the NE Tibetan Plateau received continuous Eocene-Miocene fine-grained sediments, providing an excellent opportunity to address this question. Here we present detailed rock magnetic and diffuse reflectance spectroscopy (DRS) analyses for a well-dated Cenozoic sedimentary record from the Xiejia section in the basin. Magnetic susceptibility (chi), saturation magnetization (Ms) and saturation isothermal remanent magnetization (SIRM) in this section show a long-term decreasing trend from similar to 52 to similar to 25 Ma, well coinciding with Global Cooling and drying in the region, and an increasing trend since similar to 25 Ma, which is in contrast to the further progressing aridification of the basin. Thermomagnetic results and DRS-determined hematite contents suggest that the relative content of magnetite and hematite is the main control on the chi, Ms and SIRM values. We argue that the long-term Eocene-Oligocene Global Cooling increased the drying of the Asian inland, lowering the lake level and exposing a larger area to low temperature oxidation for longer times, thus producing more hematite and leading to the decreasing trend of magnetic concentration parameters from similar to 52 to similar to 25 Ma. An intensive uplift of the NE Tibetan Plateau since similar to 25 Ma, associated with a change in the sedimentary source, might be responsible for the increase of chi, Ms and SIRM after 25 Ma.

Shuang Dai - One of the best experts on this subject based on the ideXlab platform.

  • an eocene miocene continuous rock magnetic record from the sediments in the xining basin nw china indication for cenozoic persistent drying driven by Global Cooling and tibetan plateau uplift
    Geophysical Journal International, 2015
    Co-Authors: Xiaomin Fang, Chunhui Song, Jinbo Zan, Erwin Appel, Shuang Dai, Shibo Tuo
    Abstract:

    Tibetan Plateau uplift and Global Cooling have generally been thought to have caused the drying of the Asian inland, but how and when these factors drove the aridification is unknown. The Xining Basin at the NE Tibetan Plateau received continuous Eocene-Miocene fine-grained sediments, providing an excellent opportunity to address this question. Here we present detailed rock magnetic and diffuse reflectance spectroscopy (DRS) analyses for a well-dated Cenozoic sedimentary record from the Xiejia section in the basin. Magnetic susceptibility (chi), saturation magnetization (Ms) and saturation isothermal remanent magnetization (SIRM) in this section show a long-term decreasing trend from similar to 52 to similar to 25 Ma, well coinciding with Global Cooling and drying in the region, and an increasing trend since similar to 25 Ma, which is in contrast to the further progressing aridification of the basin. Thermomagnetic results and DRS-determined hematite contents suggest that the relative content of magnetite and hematite is the main control on the chi, Ms and SIRM values. We argue that the long-term Eocene-Oligocene Global Cooling increased the drying of the Asian inland, lowering the lake level and exposing a larger area to low temperature oxidation for longer times, thus producing more hematite and leading to the decreasing trend of magnetic concentration parameters from similar to 52 to similar to 25 Ma. An intensive uplift of the NE Tibetan Plateau since similar to 25 Ma, associated with a change in the sedimentary source, might be responsible for the increase of chi, Ms and SIRM after 25 Ma.

  • An Eocene–Miocene continuous rock magnetic record from the sediments in the Xining Basin, NW China: indication for Cenozoic persistent drying driven by Global Cooling and Tibetan Plateau uplift
    Geophysical Journal International, 2015
    Co-Authors: Xiaomin Fang, Chunhui Song, Jinbo Zan, Erwin Appel, Shuang Dai, Shibo Tuo
    Abstract:

    Tibetan Plateau uplift and Global Cooling have generally been thought to have caused the drying of the Asian inland, but how and when these factors drove the aridification is unknown. The Xining Basin at the NE Tibetan Plateau received continuous Eocene-Miocene fine-grained sediments, providing an excellent opportunity to address this question. Here we present detailed rock magnetic and diffuse reflectance spectroscopy (DRS) analyses for a well-dated Cenozoic sedimentary record from the Xiejia section in the basin. Magnetic susceptibility (chi), saturation magnetization (Ms) and saturation isothermal remanent magnetization (SIRM) in this section show a long-term decreasing trend from similar to 52 to similar to 25 Ma, well coinciding with Global Cooling and drying in the region, and an increasing trend since similar to 25 Ma, which is in contrast to the further progressing aridification of the basin. Thermomagnetic results and DRS-determined hematite contents suggest that the relative content of magnetite and hematite is the main control on the chi, Ms and SIRM values. We argue that the long-term Eocene-Oligocene Global Cooling increased the drying of the Asian inland, lowering the lake level and exposing a larger area to low temperature oxidation for longer times, thus producing more hematite and leading to the decreasing trend of magnetic concentration parameters from similar to 52 to similar to 25 Ma. An intensive uplift of the NE Tibetan Plateau since similar to 25 Ma, associated with a change in the sedimentary source, might be responsible for the increase of chi, Ms and SIRM after 25 Ma.

  • tibetan plateau aridification linked to Global Cooling at the eocene oligocene transition
    Nature, 2007
    Co-Authors: Guillaume Dupontnive, Hemmo A. Abels, Shuang Dai, Wou Krijgsma, C G Langereis, Xiaomi Fang
    Abstract:

    The Eocene–Oligocene transition, about 33.5 million years ago, was a major Global climate event. The end of the Eocene was unusually warm with no significant ice on Antarctica but the Oligocene saw the arrival of a permanent Antarctic ice-sheet. Two papers this week relate to the continental effects of this Global change. Dupont-Nivet et al. examined sedimentary records from the Tibetan plateau and find a drop in atmospheric water, which caused Cooling and aridification coincident with Antarctic Cooling. Previous studies attributed this phenomenon to the rapid uplift of the Tibetan plateau, but this new work suggests that regional Tibetan climate was influenced by Global events. In an unrelated paper on the same climate transition, Zanazzi et al. explore the Cooling in North America at the time. Using stable isotope measurements from fossil teeth and bones to create a proxy temperature record, they find a large drop in mean annual temperature of 8.2 °C — a greater fall than seen in the oceans. This continental transition may explain why many cold-blooded reptiles and amphibians became extinct whereas mammals — able to regulate their body temperature — escaped relatively unscathed. Precisely dated evidence details that aridification on the Tibetan Plateau occurred at the time of the Eocene–Oligocene transition in the marine records. This suggests a direct link between the palaeontological and palaeoenvironmental changes recorded in continental Asia at the time and Global climate Cooling. Continental aridification and the intensification of the monsoons in Asia are generally attributed to uplift of the Tibetan plateau and to the land–sea redistributions associated with the continental collision of India and Asia1,2,3, whereas some studies suggest that past changes in Asian environments are mainly governed by Global climate4,5,6. The most dramatic climate event since the onset of the collision of India and Asia is the Eocene–Oligocene transition, an abrupt Cooling step associated with the onset of glaciation in Antarctica 34 million years ago7,8,9. However, the influence of this Global event on Asian environments is poorly understood. Here we use magnetostratigraphy and cyclostratigraphy to show that aridification, which is indicated by the disappearance of playa lake deposits in the northeastern Tibetan plateau, occurred precisely at the time of the Eocene–Oligocene transition. Our findings suggest that this Global transition is linked to significant aridification and Cooling in continental Asia recorded by palaeontological and palaeoenvironmental changes10,11,12, and thus support the idea that Global Cooling is associated with the Eocene–Oligocene transition13,14,15. We show that, with sufficient age control on the sedimentary records, Global climate can be distinguished from tectonism and recognized as a major contributor to continental Asian environments.

  • Tibetan plateau aridification linked to Global Cooling at the Eocene–Oligocene transition
    Nature, 2007
    Co-Authors: Guillaume Dupont-nivet, Hemmo A. Abels, Wout Krijgsman, Shuang Dai, C G Langereis, Xiaomin Fang
    Abstract:

    The Eocene–Oligocene transition, about 33.5 million years ago, was a major Global climate event. The end of the Eocene was unusually warm with no significant ice on Antarctica but the Oligocene saw the arrival of a permanent Antarctic ice-sheet. Two papers this week relate to the continental effects of this Global change. Dupont-Nivet et al. examined sedimentary records from the Tibetan plateau and find a drop in atmospheric water, which caused Cooling and aridification coincident with Antarctic Cooling. Previous studies attributed this phenomenon to the rapid uplift of the Tibetan plateau, but this new work suggests that regional Tibetan climate was influenced by Global events. In an unrelated paper on the same climate transition, Zanazzi et al. explore the Cooling in North America at the time. Using stable isotope measurements from fossil teeth and bones to create a proxy temperature record, they find a large drop in mean annual temperature of 8.2 °C — a greater fall than seen in the oceans. This continental transition may explain why many cold-blooded reptiles and amphibians became extinct whereas mammals — able to regulate their body temperature — escaped relatively unscathed. Precisely dated evidence details that aridification on the Tibetan Plateau occurred at the time of the Eocene–Oligocene transition in the marine records. This suggests a direct link between the palaeontological and palaeoenvironmental changes recorded in continental Asia at the time and Global climate Cooling. Continental aridification and the intensification of the monsoons in Asia are generally attributed to uplift of the Tibetan plateau and to the land–sea redistributions associated with the continental collision of India and Asia1,2,3, whereas some studies suggest that past changes in Asian environments are mainly governed by Global climate4,5,6. The most dramatic climate event since the onset of the collision of India and Asia is the Eocene–Oligocene transition, an abrupt Cooling step associated with the onset of glaciation in Antarctica 34 million years ago7,8,9. However, the influence of this Global event on Asian environments is poorly understood. Here we use magnetostratigraphy and cyclostratigraphy to show that aridification, which is indicated by the disappearance of playa lake deposits in the northeastern Tibetan plateau, occurred precisely at the time of the Eocene–Oligocene transition. Our findings suggest that this Global transition is linked to significant aridification and Cooling in continental Asia recorded by palaeontological and palaeoenvironmental changes10,11,12, and thus support the idea that Global Cooling is associated with the Eocene–Oligocene transition13,14,15. We show that, with sufficient age control on the sedimentary records, Global climate can be distinguished from tectonism and recognized as a major contributor to continental Asian environments.

Xiaomi Fang - One of the best experts on this subject based on the ideXlab platform.

  • tibetan plateau aridification linked to Global Cooling at the eocene oligocene transition
    Nature, 2007
    Co-Authors: Guillaume Dupontnive, Hemmo A. Abels, Shuang Dai, Wou Krijgsma, C G Langereis, Xiaomi Fang
    Abstract:

    The Eocene–Oligocene transition, about 33.5 million years ago, was a major Global climate event. The end of the Eocene was unusually warm with no significant ice on Antarctica but the Oligocene saw the arrival of a permanent Antarctic ice-sheet. Two papers this week relate to the continental effects of this Global change. Dupont-Nivet et al. examined sedimentary records from the Tibetan plateau and find a drop in atmospheric water, which caused Cooling and aridification coincident with Antarctic Cooling. Previous studies attributed this phenomenon to the rapid uplift of the Tibetan plateau, but this new work suggests that regional Tibetan climate was influenced by Global events. In an unrelated paper on the same climate transition, Zanazzi et al. explore the Cooling in North America at the time. Using stable isotope measurements from fossil teeth and bones to create a proxy temperature record, they find a large drop in mean annual temperature of 8.2 °C — a greater fall than seen in the oceans. This continental transition may explain why many cold-blooded reptiles and amphibians became extinct whereas mammals — able to regulate their body temperature — escaped relatively unscathed. Precisely dated evidence details that aridification on the Tibetan Plateau occurred at the time of the Eocene–Oligocene transition in the marine records. This suggests a direct link between the palaeontological and palaeoenvironmental changes recorded in continental Asia at the time and Global climate Cooling. Continental aridification and the intensification of the monsoons in Asia are generally attributed to uplift of the Tibetan plateau and to the land–sea redistributions associated with the continental collision of India and Asia1,2,3, whereas some studies suggest that past changes in Asian environments are mainly governed by Global climate4,5,6. The most dramatic climate event since the onset of the collision of India and Asia is the Eocene–Oligocene transition, an abrupt Cooling step associated with the onset of glaciation in Antarctica 34 million years ago7,8,9. However, the influence of this Global event on Asian environments is poorly understood. Here we use magnetostratigraphy and cyclostratigraphy to show that aridification, which is indicated by the disappearance of playa lake deposits in the northeastern Tibetan plateau, occurred precisely at the time of the Eocene–Oligocene transition. Our findings suggest that this Global transition is linked to significant aridification and Cooling in continental Asia recorded by palaeontological and palaeoenvironmental changes10,11,12, and thus support the idea that Global Cooling is associated with the Eocene–Oligocene transition13,14,15. We show that, with sufficient age control on the sedimentary records, Global climate can be distinguished from tectonism and recognized as a major contributor to continental Asian environments.

Yunfa Miao - One of the best experts on this subject based on the ideXlab platform.

  • Evidence of continuous Asian summer monsoon weakening as a response to Global Cooling over the last 8 Ma
    Gondwana Research, 2017
    Co-Authors: Yunfa Miao, Peter D. Clift, Sophie Warny, Chang Liu, Mitchell Gregory
    Abstract:

    Abstract The Asian Summer Monsoon (ASM) is the dominant climate system of South and East Asia. However, the history of monsoon intensification and the driving forces behind it are controversial. Wind-blown sediments in mid-latitude East Asia and fluvial-derived sediments in the northern South China Sea imply contrasting ASM patterns during the late Cenozoic. Here we use pollen records from the southwest South China Sea (International Ocean Discovery Program (IODP) Site U1433) to reconstruct the ASM evolution in low-latitude Southeast Asia. A slow increase in herbaceous plants since 8 Ma indicates a persistent weakening of precipitation in Indochina, which is dominated by the ASM. This signal is closely associated with a consistent coniferous plant record, indicating a continuous Cooling trend that correlates well with Sea Surface Temperature (SST) decrease in the west Pacific Ocean. We propose that the monsoon weakening resulted in as much as a ~ 25% reduction in precipitation over the past 8 Ma in response to the Northern Hemisphere glaciation/Global Cooling, with some of the increase in conifers being linked to uplift of the Vietnamese Central Highland and the SE flank of the Tibetan Plateau in Yunnan and northern Vietnam.

  • Late Cenozoic sporopollen records in the Yangtze River Delta, East China and implications for East Asian summer monsoon evolution
    Palaeogeography Palaeoclimatology Palaeoecology, 2013
    Co-Authors: Ping Zhang, Yunfa Miao, Zhiyong Zhang, Yanjie Zhang, Huogen Chen, Qiaoyin Miao, Wenli Feng
    Abstract:

    Abstract The late Cenozoic East Asian summer monsoon (EASM) is generally linked with the Tibetan Plateau uplift and/or Global Cooling. In this study, four cores (ZK004, ZK005, SZ03 and SZ04) consisting of fluvial–lacustrine deposits spanning the period of ~ 8.0–0 Ma were obtained from the Yangtze River Delta, East China for sporopollen analysis to investigate trends in the EASM evolution and its driving forces. The results show that high percentages of arboreal taxa (such as Fagaceae, Ulmaceae, Juglandaceae, Taxaceae–Taxodiaceae, Liquidambar, Anacardiaceae, Rutaceae, etc.) represent a relatively warm and humid climate between ~ 8.0 and 2.6 Ma. The herb-dominated vegetation (Poceae, Asteraceae, Cyperaceae, etc.) is linked with a relatively cold and dry climate after ~ 2.6 Ma. The compiled thermophilic percentages and AP (arbors)/NAP (non-arbors) ratios of these four cores, which show that the long-term Cooling and drying trends are similar to the Global Cooling since ~ 8.0 Ma, imply that the EASM experienced long-term weakening coincident with the Global Cooling. However, over this super-long time scale, the thermophilic percentages and AP/NAP ratios have remained at roughly stable levels since ~ 2.6 Ma, possibly due to the effects of the Tibetan Plateau uplifts.

  • What controlled Mid-Late Miocene long-term aridification in Central Asia? - Global Cooling or Tibetan Plateau uplift: A review
    Earth-Science Reviews, 2012
    Co-Authors: Yunfa Miao, Mark Herrmann, Xiaoli Yan, Shengli Yang
    Abstract:

    Abstract Debate continues over whether Global Cooling or uplift of the Tibetan Plateau provided the first-order driver for the aridification (moisture levels) of Central Asia throughout the Mid–Late Miocene, between about 17 and 5 Ma. This review attempts to throw new light on the relations between the aridification and these two key factors. This paper examines the evolution of Miocene climate (both moisture and temperature) within five separate regions of Eurasia to help understand the large scale controls of long-term moisture in Central Asia. The five regions include: (1) Europe, (2) high-latitude Asia, (3) the East Asian Monsoon region, (4) the South Asian Monsoon region, and (5) Central Asia itself, because moisture reaching Central Asia has to firstly cross at least one of the other four regions. Temperature proxy data compiled from these five regions correlate with ocean temperatures from the Global deep-sea oxygen isotope records. Furthermore, compiled moisture proxy data from the four regions surrounding Central Asia co-vary and correlate with each other. This can be explained by positive feedbacks between drying and Cooling, and supports the assumption that Global Cooling provides a dominant driving factor for the drying of Eurasia: Global Cooling reduces the amount of water vapor held in the atmosphere and thereby can cause terrestrial drying. However, in Central Asia the moisture evolution shows less similarity with its surroundings. The uplift of the Tibetan Plateau (including the Tianshan Mountains) could provide a possible explanation for this difference. The changing topography resulting from uplift events over time and space strongly influenced the moisture patterns in Central Asia during Miocene times. Future research on the spatial timing and amplitude of Tibetan Plateau uplift should be useful to understand the moisture processes in Central Asia during the Miocene.

  • Northern Tibetan Plateau Cooling and aridification linked to Cenozoic Global Cooling: Evidence from n-alkane distributions of Paleogene sedimentary sequences in the Xining Basin
    Chinese Science Bulletin, 2011
    Co-Authors: Liqun Long, Xiaomin Fang, Yunfa Miao, Yan Bai, Yongli Wang
    Abstract:

    The Xining Basin on the northeastern Tibetan Plateau holds the longest continuous Cenozoic stratigraphic record in China. The sequence record contains considerable information on the history of Tibetan uplift and associated climatic change. In particular, high resolution n-alkane biomarker proxy and pollen records have been obtained from the Paleogene sediments of the Xiejia section of the basin. A combination of the n-alkane and palynological records reveals that the paleoclimate in the Xining Basin experienced a long-term Cooling trend from 50.2 to 28.2 Ma with a distinctive ecological event spanning 37.5 to 32.7 Ma. Since this ecological event, a vertical zonation of vegetation from lowland arid grasses, to middle-elevation subtropical broad-leaf plants, to high-elevation coniferous trees was established. We interpret that these changes in climate and vegetation were probably responses to a combination of long term Global Cooling since the Eocene climatic optimum and uplift of the surrounding mountains on the northern Tibetan Plateau in the early Cenozoic.