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Research paper thumbnail of Plio-Pleistocene Paleoclimate and Paleoelevation in the Northern Tibetan Plateau: Implications for the Establishment of Alpine permafrost and its stability during global climate change

AGU Fall Meeting Abstracts, Dec 1, 2020

Research paper thumbnail of Supplemental Material: Plio-Pleistocene cooling of the northeastern Tibetan Plateau due to global climate change and surface uplift

A description and discussion of methods; additional figures showing core photographs, geochemical... more A description and discussion of methods; additional figures showing core photographs, geochemical data, statistical data, and models relating soil/lake and air temperatures; complete geochemical datasets and tabled analytical results; and tables containing statistical treatment of data and compilation of environmental datasets.

Research paper thumbnail of How Useful Are Foreland Basin Strata for Interpreting Tectonics?– an Example from the Southern Tian Shan Foreland, China

Geological Society of America Abstracts with Programs

Research paper thumbnail of Plio-Pleistocene cooling of the northeastern Tibetan Plateau due to global climate change and surface uplift

GSA Bulletin

It has been proposed that the northeastern Tibetan Plateau (NETP) was the most recent plateau sub... more It has been proposed that the northeastern Tibetan Plateau (NETP) was the most recent plateau sub-region to gain elevation, leading to profound environmental changes in northern East Asia around the mid-Pliocene (ca. 3.6 Ma). Alternatively, environmental changes in the region have been linked to ongoing global cooling and glacial intensification after 3.3 Ma. Here, we test these hypotheses using Plio-Pleistocene estimates of paleotemperatures and paleoelevations in the NETP derived from oxygen and carbon stable isotopic composition (n = 792) and clumped isotope measurements (n = 32) of carbonates from a Lake Qinghai Basin sediment core, eastern NETP. From 5 to 2 Ma, basinal mean annual air temperatures (MAATs) decreased by 4.9 ± 2.8 °C at rates of 1.6 °C ± 0.5 °C/myr, concurrently with regional and global cooling. However, the largest MAAT decline occurs between ca. 4.8−3.7 Ma (4.1 ± 3.2 °C) and ca. 3.4−2.0 Ma (−0.3 ± 2.8 °C) and may correspond with an elevation change of 1.0 ± 1.0 ...

Research paper thumbnail of Stable isotope evidence for the Cenozoic paleoclimate evolution of the Hexi Corridor, Northern Tibetan Plateau

Research paper thumbnail of Abrupt cooling and surface uplift at 3.6 Ma in the Northeastern Tibetan Plateau and changes in dust source region to the Chinese Loess Plateau

Research paper thumbnail of Growth of the southern Tian Shan-Pamir and its impact on central Asian climate

GSA Bulletin

Uplift and amalgamation of the high-elevation (>3000 m) Tian Shan and Pamir ranges in Central ... more Uplift and amalgamation of the high-elevation (>3000 m) Tian Shan and Pamir ranges in Central Asia restricts westerly atmospheric flow and thereby limits moisture delivery to the leeward Taklimakan Desert in the Tarim Basin (<1500 m), the second largest modern sand dune desert on Earth. Although some research suggests that the hyper-arid conditions observed today in the Tarim Basin developed by ca. 25 Ma, stratigraphic evidence suggests the first erg system did not appear until 12.2 Ma. To address this controversy and to understand the tectonic influences on climate in Central Asia, we studied a continuous, 3800-m-thick stratigraphic section deposited from 15.1 to 0.9 Ma now exposed within the western Kepintagh fold-and-thrust belt in the southern Tian Shan foreland. We present new detrital zircon data (n = 839), new carbonate oxygen (δ18Oc) and carbon (δ13Cc) stable isotope compositions (n = 368), structural modeling, and stratigraphic observations, and combine these data wit...

Research paper thumbnail of Supplemental Material: Growth of the southern Tian Shan-Pamir and its impact on central Asian climate

Supplementary Methods 1: Structure and Shortening. Supplementary Methods 2: Trishear modeling. Su... more Supplementary Methods 1: Structure and Shortening. Supplementary Methods 2: Trishear modeling. Supplementary Data 1: References for compiled thermochronology (AFT) data. Table S1: Carbonate δ13C (‰VPDB) and δ18O (‰VPDB) isotopic results and mean values; descriptions of samples and outcrops; interpretations of depositional environments. Table S2: Descriptions, interpreted paleoenvironments and references for locations in Figure 11. Table S3: U-Pb data unknowns. Table S4: U-Pb Temora-2 standard data. Table S5: Statistical analysis of detrital zircon data. Table S6: Location of detrital zircon samples.

Research paper thumbnail of Late Cretaceous through Cenozoic Paleoenvironmental History of the Bagua Basin, Peru: Paleoelevation Comparisons with the Central Andean Plateau

Geosciences

Located in northern Peru, at the lowest segment of the Central Andes, the Bagua Basin contains a ... more Located in northern Peru, at the lowest segment of the Central Andes, the Bagua Basin contains a Campanian to Pleistocene sedimentary record that archives the local paleoenvironmental and tectonic history. We present new δ18O and δ13C signatures of pedogenic carbonate nodules from paleosols in the Campanian–Maastrichtian Fundo El Triunfo Formation and in the upper Eocene–middle Miocene Sambimera Formation to reconstruct the isotopic composition of paleo-meteoric water and the floristic biome. We compare these results to modern isotopic values from a newly obtained modern water transect to interpret the environmental evolution of this area and its relationship with the neighboring Eastern Cordillera. A ~2‰ δ18O depletion between the latest Cretaceous and the latest Eocene reflects a shift from a coastal to inland environment. A negative δ18O shift of ~3‰ from the middle Miocene to the present day reveals the establishment of the Eastern Cordillera as an orographic barrier for the moi...

Research paper thumbnail of 14.6 Ma Aridification and Development of the Ancestral Taklimakan Desert Between the Pamir and Tian Shan Orogens, Western China

Geological Society of America Abstracts with Programs

Research paper thumbnail of Sedimentation, metamorphism and granite generation in a Back-Arc Region : the crustal processes recorded in the Ediacaran Nova Venécia Complex (Araçuaí Orogen, Southeast Brazil)

The Nova Venécia migmatite-granulite-granite Complex (NVC) in the core of the Araçuaí Orogen (AO,... more The Nova Venécia migmatite-granulite-granite Complex (NVC) in the core of the Araçuaí Orogen (AO, 630-480 Ma), southeast Brazil, exposes a mid-crustal section with abundant evidence for production, extraction and emplacement of peraluminous melts. In this study we combine U-Pb geochronology and metamorphic petrology to constrain the evolution of the NVC migmatites-granulites from deposition to high-grade metamorphism, and to correlate the metamorphic history of the terrain with the several episodes of granite magmatism (G1-G5) in the AO. The sedimentation of the NVC can be bracketed within at least a 16 Ma period, between its maximum depositional age at ca. 606 Ma and the intrusion of early syn-collisional granitoids at 593 Ma. Compilation of available U-Pb data shows that the bulk of the magmatic rocks in the AO (G1 + G2 rocks) crystallized contemporaneously over a period of 15 My (ca. 595-570 Ma) with a peak at ca. 575 Ma. Altough it is inferred a protacted period of crustal heati...

Research paper thumbnail of Coupled Andean growth and foreland basin evolution, Campanian–Cenozoic Bagua Basin, northern Peru

Research paper thumbnail of Erg deposition and development of the ancestral Taklimakan Desert (western China) between 12.2 and 7.0 Ma

Geology

The Taklimakan Desert in western China contains the second largest shifting sand desert on earth.... more The Taklimakan Desert in western China contains the second largest shifting sand desert on earth. The onset of this desert formation has been debated between the Eocene, early Miocene, late Miocene, or Pliocene, with each hypothesis having profound implications for the climatic and tectonic evolution of this region. We provide stratigraphic evidence for desert formation based on a new 3800-m-thick stratigraphic section in the northwestern Tarim Basin. Magnetostratigraphy defines 50 magnetozones and constrains the age of these strata to between ca. 15.1 and 1.5 Ma. Fluvial and lacustrine strata at the base of the section change abruptly to eolian sandstone (~1100 m thick) at 12.2 Ma and persist until 7.0 Ma, implying development of an erg system that represents the ancestral Taklimakan Desert. The appearance of sand dunes at 12.2 Ma has no global climate parallel, and resulted from aridification in the rain-shadow behind a growing Tian Shan and Pamir that isolated the Tarim Basin.

Research paper thumbnail of Tectonically Forced Carbonate Oxygen and Carbon Isotope Shifts Since 15 Ma in the Tian Shan Foreland, Tarim Basin China

Research paper thumbnail of 5-2 Ma High-Resolution Stable Isotope Record from Carbonates Formed in the Qinghai Lake During Outward Growth of the Qilian Shan-Nan Shan Orogenic Belt and Global Cooling

Research paper thumbnail of Provenance analysis of the Yumen Basin and northern Qilian Shan: Implications for the pre-collisional paleogeography in the NE Tibetan plateau and eastern termination of Altyn Tagh fault

Gondwana Research

Understanding the pre-collisional paleogeography in the NE Tibetan plateau provides insights into... more Understanding the pre-collisional paleogeography in the NE Tibetan plateau provides insights into the growth mechanisms of the northern portion of the plateau in the Cenozoic. We conducted sandstone petrography analysis and determined U-Pb ages for detrital zircons from Cretaceous sandstone from the Yumen Basin and the northern Qilian Shan. Cretaceous strata in the northern Yumen Basin yield a unimodal age population at 290-240 Ma that indicates primary derivation from Bei Shan. Cretaceous strata in the westernmost Yumen Basin contain zircons of 2.6-2.2 Ga, 2.1-1.7 Ga, 1.4-0.7 Ga, 440-380 Ma and 300-230 Ma, suggesting source derivation from both the Qilian Shan and Bei Shan. Within the northern Qilian Shan, Cretaceous strata yield age populations of 2.8-2.3 Ga, 2.1-1.2 Ga, 480-380 Ma and ca. 270 Ma, indicating derivation from the Qilian Shan. Sandstone composition results show that a sample from the northern Qilian Shan contains more lithic fragments and plots in the recycled orogen field of the quartz-feldspar-lithics (QFL) diagram, while samples from Yumen Basin are more quartz-rich and plot close to the continental block field of the QFL diagram. This compositional difference corresponds to source variation, consistent with the detrital zircon record. Combined with existing sedimentology and low-temperature thermochronology datasets, we suggest the presence of Cretaceous topographic relief in the Bei Shan and Qilian Shan prior to India-Asia collision. Considering >300 km post-Cretaceous left-lateral offset along the Altyn Tagh Fault (ATF) and the consistently similar detrital zircon ages spectra of the samples from the Cretaceous to late Oligocene strata in the Yumen Basin, we infer the palaeogeography in the NE Tibetan plateau has been similar from the late Cretaceous to the late Oligocene with ATF termination in the western Yumen Basin instead of having been linked to strike-slip faults in the Alxa or other regions to the east since its initiation.

Research paper thumbnail of Sedimentation, Metamorphism and Granite Generation in a Back-Arc Region: Records from the Ediacaran Nova Venécia Complex (Araçuaí Orogen, Southeastern Brazil)

Precambrian Research, 2015

Research paper thumbnail of Erg deposition and development of the ancestral Taklimakan Desert (western China) between 12.2 and 7.0 Ma

Geology, Sep 11, 2018

The Taklimakan Desert in western China contains the second largest shifting sand desert on earth.... more The Taklimakan Desert in western China contains the second largest shifting sand desert on earth. The onset of this desert formation has been debated between the Eocene, early Miocene, late Miocene, or Pliocene, with each hypothesis having profound implications for the climatic and tectonic evolution of this region. We provide stratigraphic evidence for desert formation based on a new 3800-m-thick stratigraphic section in the northwestern Tarim Basin. Magnetostratigraphy defines 50 magnetozones and constrains the age of these strata to between ca. 15.1 and 1.5 Ma. Fluvial and lacustrine strata at the base of the section change abruptly to eolian sandstone (~1100 m thick) at 12.2 Ma and persist until 7.0 Ma, implying development of an erg system that represents the ancestral Taklimakan Desert. The appearance of sand dunes at 12.2 Ma has no global climate parallel, and resulted from aridification in the rain-shadow behind a growing Tian Shan and Pamir that isolated the Tarim Basin.

Research paper thumbnail of Erg deposition and development of the ancestral Taklimakan Desert (western China) between 12.2 and 7.0 Ma

Geology, Sep 11, 2018

The Taklimakan Desert in western China contains the second largest shifting sand desert on earth.... more The Taklimakan Desert in western China contains the second largest shifting sand desert on earth. The onset of this desert formation has been debated between the Eocene, early Miocene, late Miocene, or Pliocene, with each hypothesis having profound implications for the climatic and tectonic evolution of this region. We provide stratigraphic evidence for desert formation based on a new 3800-m-thick stratigraphic section in the northwestern Tarim Basin. Magnetostratigraphy defines 50 magnetozones and constrains the age of these strata to between ca. 15.1 and 1.5 Ma. Fluvial and lacustrine strata at the base of the section change abruptly to eolian sandstone (~1100 m thick) at 12.2 Ma and persist until 7.0 Ma, implying development of an erg system that represents the ancestral Taklimakan Desert. The appearance of sand dunes at 12.2 Ma has no global climate parallel, and resulted from aridification in the rain-shadow behind a growing Tian Shan and Pamir that isolated the Tarim Basin.

Research paper thumbnail of Plio-Pleistocene Paleoclimate and Paleoelevation in the Northern Tibetan Plateau: Implications for the Establishment of Alpine permafrost and its stability during global climate change

AGU Fall Meeting Abstracts, Dec 1, 2020

Research paper thumbnail of Supplemental Material: Plio-Pleistocene cooling of the northeastern Tibetan Plateau due to global climate change and surface uplift

A description and discussion of methods; additional figures showing core photographs, geochemical... more A description and discussion of methods; additional figures showing core photographs, geochemical data, statistical data, and models relating soil/lake and air temperatures; complete geochemical datasets and tabled analytical results; and tables containing statistical treatment of data and compilation of environmental datasets.

Research paper thumbnail of How Useful Are Foreland Basin Strata for Interpreting Tectonics?– an Example from the Southern Tian Shan Foreland, China

Geological Society of America Abstracts with Programs

Research paper thumbnail of Plio-Pleistocene cooling of the northeastern Tibetan Plateau due to global climate change and surface uplift

GSA Bulletin

It has been proposed that the northeastern Tibetan Plateau (NETP) was the most recent plateau sub... more It has been proposed that the northeastern Tibetan Plateau (NETP) was the most recent plateau sub-region to gain elevation, leading to profound environmental changes in northern East Asia around the mid-Pliocene (ca. 3.6 Ma). Alternatively, environmental changes in the region have been linked to ongoing global cooling and glacial intensification after 3.3 Ma. Here, we test these hypotheses using Plio-Pleistocene estimates of paleotemperatures and paleoelevations in the NETP derived from oxygen and carbon stable isotopic composition (n = 792) and clumped isotope measurements (n = 32) of carbonates from a Lake Qinghai Basin sediment core, eastern NETP. From 5 to 2 Ma, basinal mean annual air temperatures (MAATs) decreased by 4.9 ± 2.8 °C at rates of 1.6 °C ± 0.5 °C/myr, concurrently with regional and global cooling. However, the largest MAAT decline occurs between ca. 4.8−3.7 Ma (4.1 ± 3.2 °C) and ca. 3.4−2.0 Ma (−0.3 ± 2.8 °C) and may correspond with an elevation change of 1.0 ± 1.0 ...

Research paper thumbnail of Stable isotope evidence for the Cenozoic paleoclimate evolution of the Hexi Corridor, Northern Tibetan Plateau

Research paper thumbnail of Abrupt cooling and surface uplift at 3.6 Ma in the Northeastern Tibetan Plateau and changes in dust source region to the Chinese Loess Plateau

Research paper thumbnail of Growth of the southern Tian Shan-Pamir and its impact on central Asian climate

GSA Bulletin

Uplift and amalgamation of the high-elevation (>3000 m) Tian Shan and Pamir ranges in Central ... more Uplift and amalgamation of the high-elevation (>3000 m) Tian Shan and Pamir ranges in Central Asia restricts westerly atmospheric flow and thereby limits moisture delivery to the leeward Taklimakan Desert in the Tarim Basin (<1500 m), the second largest modern sand dune desert on Earth. Although some research suggests that the hyper-arid conditions observed today in the Tarim Basin developed by ca. 25 Ma, stratigraphic evidence suggests the first erg system did not appear until 12.2 Ma. To address this controversy and to understand the tectonic influences on climate in Central Asia, we studied a continuous, 3800-m-thick stratigraphic section deposited from 15.1 to 0.9 Ma now exposed within the western Kepintagh fold-and-thrust belt in the southern Tian Shan foreland. We present new detrital zircon data (n = 839), new carbonate oxygen (δ18Oc) and carbon (δ13Cc) stable isotope compositions (n = 368), structural modeling, and stratigraphic observations, and combine these data wit...

Research paper thumbnail of Supplemental Material: Growth of the southern Tian Shan-Pamir and its impact on central Asian climate

Supplementary Methods 1: Structure and Shortening. Supplementary Methods 2: Trishear modeling. Su... more Supplementary Methods 1: Structure and Shortening. Supplementary Methods 2: Trishear modeling. Supplementary Data 1: References for compiled thermochronology (AFT) data. Table S1: Carbonate δ13C (‰VPDB) and δ18O (‰VPDB) isotopic results and mean values; descriptions of samples and outcrops; interpretations of depositional environments. Table S2: Descriptions, interpreted paleoenvironments and references for locations in Figure 11. Table S3: U-Pb data unknowns. Table S4: U-Pb Temora-2 standard data. Table S5: Statistical analysis of detrital zircon data. Table S6: Location of detrital zircon samples.

Research paper thumbnail of Late Cretaceous through Cenozoic Paleoenvironmental History of the Bagua Basin, Peru: Paleoelevation Comparisons with the Central Andean Plateau

Geosciences

Located in northern Peru, at the lowest segment of the Central Andes, the Bagua Basin contains a ... more Located in northern Peru, at the lowest segment of the Central Andes, the Bagua Basin contains a Campanian to Pleistocene sedimentary record that archives the local paleoenvironmental and tectonic history. We present new δ18O and δ13C signatures of pedogenic carbonate nodules from paleosols in the Campanian–Maastrichtian Fundo El Triunfo Formation and in the upper Eocene–middle Miocene Sambimera Formation to reconstruct the isotopic composition of paleo-meteoric water and the floristic biome. We compare these results to modern isotopic values from a newly obtained modern water transect to interpret the environmental evolution of this area and its relationship with the neighboring Eastern Cordillera. A ~2‰ δ18O depletion between the latest Cretaceous and the latest Eocene reflects a shift from a coastal to inland environment. A negative δ18O shift of ~3‰ from the middle Miocene to the present day reveals the establishment of the Eastern Cordillera as an orographic barrier for the moi...

Research paper thumbnail of 14.6 Ma Aridification and Development of the Ancestral Taklimakan Desert Between the Pamir and Tian Shan Orogens, Western China

Geological Society of America Abstracts with Programs

Research paper thumbnail of Sedimentation, metamorphism and granite generation in a Back-Arc Region : the crustal processes recorded in the Ediacaran Nova Venécia Complex (Araçuaí Orogen, Southeast Brazil)

The Nova Venécia migmatite-granulite-granite Complex (NVC) in the core of the Araçuaí Orogen (AO,... more The Nova Venécia migmatite-granulite-granite Complex (NVC) in the core of the Araçuaí Orogen (AO, 630-480 Ma), southeast Brazil, exposes a mid-crustal section with abundant evidence for production, extraction and emplacement of peraluminous melts. In this study we combine U-Pb geochronology and metamorphic petrology to constrain the evolution of the NVC migmatites-granulites from deposition to high-grade metamorphism, and to correlate the metamorphic history of the terrain with the several episodes of granite magmatism (G1-G5) in the AO. The sedimentation of the NVC can be bracketed within at least a 16 Ma period, between its maximum depositional age at ca. 606 Ma and the intrusion of early syn-collisional granitoids at 593 Ma. Compilation of available U-Pb data shows that the bulk of the magmatic rocks in the AO (G1 + G2 rocks) crystallized contemporaneously over a period of 15 My (ca. 595-570 Ma) with a peak at ca. 575 Ma. Altough it is inferred a protacted period of crustal heati...

Research paper thumbnail of Coupled Andean growth and foreland basin evolution, Campanian–Cenozoic Bagua Basin, northern Peru

Research paper thumbnail of Erg deposition and development of the ancestral Taklimakan Desert (western China) between 12.2 and 7.0 Ma

Geology

The Taklimakan Desert in western China contains the second largest shifting sand desert on earth.... more The Taklimakan Desert in western China contains the second largest shifting sand desert on earth. The onset of this desert formation has been debated between the Eocene, early Miocene, late Miocene, or Pliocene, with each hypothesis having profound implications for the climatic and tectonic evolution of this region. We provide stratigraphic evidence for desert formation based on a new 3800-m-thick stratigraphic section in the northwestern Tarim Basin. Magnetostratigraphy defines 50 magnetozones and constrains the age of these strata to between ca. 15.1 and 1.5 Ma. Fluvial and lacustrine strata at the base of the section change abruptly to eolian sandstone (~1100 m thick) at 12.2 Ma and persist until 7.0 Ma, implying development of an erg system that represents the ancestral Taklimakan Desert. The appearance of sand dunes at 12.2 Ma has no global climate parallel, and resulted from aridification in the rain-shadow behind a growing Tian Shan and Pamir that isolated the Tarim Basin.

Research paper thumbnail of Tectonically Forced Carbonate Oxygen and Carbon Isotope Shifts Since 15 Ma in the Tian Shan Foreland, Tarim Basin China

Research paper thumbnail of 5-2 Ma High-Resolution Stable Isotope Record from Carbonates Formed in the Qinghai Lake During Outward Growth of the Qilian Shan-Nan Shan Orogenic Belt and Global Cooling

Research paper thumbnail of Provenance analysis of the Yumen Basin and northern Qilian Shan: Implications for the pre-collisional paleogeography in the NE Tibetan plateau and eastern termination of Altyn Tagh fault

Gondwana Research

Understanding the pre-collisional paleogeography in the NE Tibetan plateau provides insights into... more Understanding the pre-collisional paleogeography in the NE Tibetan plateau provides insights into the growth mechanisms of the northern portion of the plateau in the Cenozoic. We conducted sandstone petrography analysis and determined U-Pb ages for detrital zircons from Cretaceous sandstone from the Yumen Basin and the northern Qilian Shan. Cretaceous strata in the northern Yumen Basin yield a unimodal age population at 290-240 Ma that indicates primary derivation from Bei Shan. Cretaceous strata in the westernmost Yumen Basin contain zircons of 2.6-2.2 Ga, 2.1-1.7 Ga, 1.4-0.7 Ga, 440-380 Ma and 300-230 Ma, suggesting source derivation from both the Qilian Shan and Bei Shan. Within the northern Qilian Shan, Cretaceous strata yield age populations of 2.8-2.3 Ga, 2.1-1.2 Ga, 480-380 Ma and ca. 270 Ma, indicating derivation from the Qilian Shan. Sandstone composition results show that a sample from the northern Qilian Shan contains more lithic fragments and plots in the recycled orogen field of the quartz-feldspar-lithics (QFL) diagram, while samples from Yumen Basin are more quartz-rich and plot close to the continental block field of the QFL diagram. This compositional difference corresponds to source variation, consistent with the detrital zircon record. Combined with existing sedimentology and low-temperature thermochronology datasets, we suggest the presence of Cretaceous topographic relief in the Bei Shan and Qilian Shan prior to India-Asia collision. Considering >300 km post-Cretaceous left-lateral offset along the Altyn Tagh Fault (ATF) and the consistently similar detrital zircon ages spectra of the samples from the Cretaceous to late Oligocene strata in the Yumen Basin, we infer the palaeogeography in the NE Tibetan plateau has been similar from the late Cretaceous to the late Oligocene with ATF termination in the western Yumen Basin instead of having been linked to strike-slip faults in the Alxa or other regions to the east since its initiation.

Research paper thumbnail of Sedimentation, Metamorphism and Granite Generation in a Back-Arc Region: Records from the Ediacaran Nova Venécia Complex (Araçuaí Orogen, Southeastern Brazil)

Precambrian Research, 2015

Research paper thumbnail of Erg deposition and development of the ancestral Taklimakan Desert (western China) between 12.2 and 7.0 Ma

Geology, Sep 11, 2018

The Taklimakan Desert in western China contains the second largest shifting sand desert on earth.... more The Taklimakan Desert in western China contains the second largest shifting sand desert on earth. The onset of this desert formation has been debated between the Eocene, early Miocene, late Miocene, or Pliocene, with each hypothesis having profound implications for the climatic and tectonic evolution of this region. We provide stratigraphic evidence for desert formation based on a new 3800-m-thick stratigraphic section in the northwestern Tarim Basin. Magnetostratigraphy defines 50 magnetozones and constrains the age of these strata to between ca. 15.1 and 1.5 Ma. Fluvial and lacustrine strata at the base of the section change abruptly to eolian sandstone (~1100 m thick) at 12.2 Ma and persist until 7.0 Ma, implying development of an erg system that represents the ancestral Taklimakan Desert. The appearance of sand dunes at 12.2 Ma has no global climate parallel, and resulted from aridification in the rain-shadow behind a growing Tian Shan and Pamir that isolated the Tarim Basin.

Research paper thumbnail of Erg deposition and development of the ancestral Taklimakan Desert (western China) between 12.2 and 7.0 Ma

Geology, Sep 11, 2018

The Taklimakan Desert in western China contains the second largest shifting sand desert on earth.... more The Taklimakan Desert in western China contains the second largest shifting sand desert on earth. The onset of this desert formation has been debated between the Eocene, early Miocene, late Miocene, or Pliocene, with each hypothesis having profound implications for the climatic and tectonic evolution of this region. We provide stratigraphic evidence for desert formation based on a new 3800-m-thick stratigraphic section in the northwestern Tarim Basin. Magnetostratigraphy defines 50 magnetozones and constrains the age of these strata to between ca. 15.1 and 1.5 Ma. Fluvial and lacustrine strata at the base of the section change abruptly to eolian sandstone (~1100 m thick) at 12.2 Ma and persist until 7.0 Ma, implying development of an erg system that represents the ancestral Taklimakan Desert. The appearance of sand dunes at 12.2 Ma has no global climate parallel, and resulted from aridification in the rain-shadow behind a growing Tian Shan and Pamir that isolated the Tarim Basin.