Glacial lake inventory of High Mountain Asia

The data set integrated glacier inventory data and 426 Landsat TM/ETM+/OLI images, and adopted manual visual interpretation to extract glacial lake boundaries within a 10-km buffer from glacier terminals using ArcGIS and ENVI software, normalized difference water index maps, and Google Earth images. It was established that 26,089 and 28,953 glacial lakes in HMA, with sizes of 0.0054–5.83 km2, covered a combined area of 1692.74 ± 231.44 and 1955.94 ± 259.68 km2 in 1990 and 2018, respectively.The current glacial lake inventory provided fundamental data for water resource evaluation, assessment of glacial lake outburst floods, and glacier hydrology research in the mountain cryosphere region

0 2019-12-20

Paleomagnetic data bearing on the Mesozoic deformation of the Qiangtang Block: Implications for the evolution of the Paleo- and Meso-Tethys

Paleomagnetism has played an important role in quantifying the Mesozoic evolution of “Proto-Tibet”. We present here our recent paleomagnetic data from five Middle-Upper Jurassic sedimentary sequences of the eastern North Qiangtang Terrane at Yanshiping. The new paleomagnetic results from 99 sites, 1,702 samples and reveal paleopoles at 79.1°N/306.9°E (dp=3.9°, dm=6.3°) for Quemo Co Fm, 68.9°N/313.8°E (dp=2.1°, dm=3.7°) for Buqu Fm, 66.1°N/332.1°E (dp=2.7°, dm=4.6°) for Xiali Fm, 72.4°N/318.6°E (dp=3.9°, dm=6.7°) for Suowa Fm, and 76.9°N/301.1°E (dp=7.9°, dm=13.2°) for Xueshan Fm, respectively. These results indicate that Yanshiping experienced latitudinal changes from ~24.5° N to ~22.0º N over the time interval 171.2 - <157.5 Ma, accompanied by clockwise (CW) rotations of ~19.8±9.4º between ~171.2 and 161.7 Ma and counterclockwise (CCW) rotations of ~15.4±13.4º between ~161.7 and <157.2 Ma. We attribute the change in rotation sense at approximately ~161.7 Ma to the initial collision of the Lhasa and Qiangtang terranes. Using this and other paleomagnetic data from the Lhasa, Qiangtang and Tarim terranes, as well as other geological evidence, such as tectonism-related sedimentary sequences, volcanism, and HP metamorphism, we propose a new conceptual evolution model for the Mesozoic QT and Tethyan Oceans, including 3 intra-continental collisions (South-North Qiangtang, Qiangtang-Songpan-Ganzi and Lhasa-Qiangtang) and post collisional extensions.

0 2019-12-19

Geomorphological map of Nima and Lunpola Basins in Tibetan Plateau

This data set comprises pictures of geological sections and landscape of Nima Basin and Lunpola Basin in the north of Tibetan Plateau which produced on achievement of geological survey in these years. The process of section pictures drawing comprises: measurement of different stratas by hand; identify and description of stratas by experienced geological researcher; picture production with software, based on information collected above. Landscape pictures were drew from satellite maps as base map, then added texts with software. All the pictures are clear, detailed and comprehensive. They are very critical for research on geology, geomorphology of the important localities in the north of Tibetan Plateau, such as Nima Basin and Lunpola Basin, and necessary for paleo-altimetry and uplift of Tibetan Plateau.

0 2019-12-18

Magnetic stratigraphy results of a 300-meter-thick Oligocene strata borehole in the Qujing region, Yunnan

The Qujing Basin is located in the eastern part of Yunnan Province, is a long and narrow rift basin with north-south trend in shape. The Basin preserves thick and continuous Cenozoic sediments, which can be divided into Xiaotun Formation, Caijiachong Formation and Ciying Formation from bottom to top. These thick Cenozoic sediments deposited are ideal achieves used to explore the history of local deformation process affected by the collision of the Indian-Eurasian plate as well as the evolution of the Indian monsoon in the Cenozoic. Previously, the macrochronological framework of these stratum was mainly defined by biological fossils, but high-resolution chronology with precise chronological control has not been carried out, thus limiting the understanding of tectonic evolution and climate and environmental changes since the Eocene in Yunnan. Based on the paleomagnetic test performed on the 300-meters thick boreholes drilled in the Qujing Basin as well as the U-Pb age (35.49 ± 0.78 Ma) results of volcanic tuff zircon collected from the top of the Caijiachong Formation, we then present the preliminary results of a precise chronological controlled high-resolution magnetic chronology record.

0 2019-12-05

Magnetic stratigraphy results of a 400-meter-thick Paleocene strata borehole in the Xiaojinggu region, Yunnan

The Simao Basin is located in the south of the Yunnan province and the southeast of the Qinghai-Tibet plateau. It is classified as the Sanjiang tectonic domain belongs to the eastern part of Tethyan tectonic domain. The thick and continuous Early Cenozoic strata preserved in the basin is thought to be an ideal achieve to reconstruct the history of tectonic evolution in this area as well as on the southeastern plateau. The most complete Early Cenozoic strata in the Simao Basin are located in Xiaojinggu Town, Jinggu County, which mainly includes the sedimentary strata of the Mengyejing Formation, the Denghei Formation and the Mengla Formation. Previously, the chronological study of sedimentary strata in the Simao Basin is mainly concentrated in the Mengyejing Formation with potassium salt. However, scholars still have significant controversy about the deposition time of this group at this stage. Further, a complete sedimentary profile containing the middle and lower part of the Mengyejing Formation could not obtain due to vegetation cover and village construction. Through the systematic thermal demagnetization analysis of the 361.86-meter-thick borehole that encompasses the entire Mengyejing Formation, a Paleocene-Cretaceous high-resolution magnetic chronology results were obtained in this area initially.

0 2019-12-05

Palaeogeographic distribution of Early, Middle and Late Triassic lithofacies in Pan-Third Pole area

Guided by plate tectonics, palaeogeography, petroleum basin analysis and sedimentary basin dynamics , a large number of data and achievements in recent years of geological and petroleum geology research in Pan-Third Pole have been collected, including basic materials such as strata, sediments, palaeontology, palaeogeography, palaeoenvironments, palaeoclimate, structure, petroleum (sylvine) geology, especially Palaeomagnetism and palaeozoic. On the basis of material, detrital zircon and geochemical data, and combined with the results of typical measured stratigraphic profiles, the lithofacies and climatic palaeogeographic pattern of the Triassic period were restored and reconstructed, and the Palaeogeographic distribution of Early, Middle and Late Triassic lithofacies in Pan-Third Pole area as well as the paleoclimatic distribution maps were obtained, aiming at discussing the control and influence of palaeogeography, palaeostructure and Palaeoclimate on hydrocarbon (potassium-bearing) resources In order to reveal the geological conditions of oil and gas formation and the law of resource distribution, and provide scientific basis and technical support for overseas and domestic oil and gas exploration and deployment in China.

0 2019-12-03

Geochemical data set of the Paleocene-Eocene thermal maximum at Gamba and Tingri, southern Tibet

This data set comes from shallow marine carbonate sections at Tingri and Gamba, south Tibet. The age of these samples is about 56 Ma (at the Paleocene-Eocene boundary). At Tingri, we studied two parallel sections (13ZS section and 10-11TM section), and at Gamba, we studied one section (11TMG). From the 13ZS section, we analyzed carbon and oxygen isotopic compositions and calcium carbonate content of the whole carbonate rock, as well as the in-situ carbon isotopic compositions and element contents of the foraminifera shell. From the 10-11TM section, we analyzed carbon, oxygen and strontium isotopic compositions of the whole rock. From the 11TMG section, we analyzed carbon and oxygen isotopic compositions of the whole carbonate rock. Carbon and oxygen isotopic compositions of the whole rock were measured by gas isotope mass spectrometer (MAT251), strontium isotope by thermal ionization mass spectrometry (TIMS), calcium carbonate content by acid dissolution, in-situ carbon isotopic compositions by SIMS, and in-situ element contents by LA-ICPMS. Among these data, in-situ carbon isotope data were obtained from the laboratory of Professor John Valley at the University of Wisconsin-Madison in the United States, and the rest are from the relevant laboratories of the Department of Geosciences at the University of Bremen in Germany. Based on these data, we published three peer-reviewed papers on Journals of Gondwana Research, GSA Bulletin, and Global and Planetary Change.

0 2019-11-29

Stable Isotope Dataset of the Sediment Core Retrieved from Lop Nor in the Tarim Basin/Dataset of field investigation and field photos of the Tibetan Plateau

This dataset includes stable carbon and oxygen isotopes of carbonates in a 180 m-long sediment core retrieved from Lop Nor, Tarim Basin. Sedimentary carbon and oxygen isotopes from carbonates are two of the most commonly used proxies in paleoclimatic studies, as they have the potential to record past variations in hydrology and vegetation. The sediment samples were grounded and sieved through a 100 mesh screen, and then directly analyzed using an isotope ratio mass spectrometer (MAT-252) with an automated carbonate preparation device (Kiel Ⅱ). Typical analytical errors are within ±0.06‰ and ±0.08‰ for carbon isotope and oxygen isotope, respectively. Based on the high-resolution stable carbon and oxygen isotope data of core Lop Nor, the evolution history of arid environment in the Taklimakan Desert since the Pleistocene can be reconstructed, allowing further exploring of trends, variability and mechanisms of regional climate change. Field photos dataset of the Tibetan Plateau include photos of the stratigraphic profiles.

0 2019-11-29

Lithology description of a 400 m-thick Paleocene strata borehole in the Xiaojinggu area, Yunnan

The most complete Early Cenozoic strata in the Simao Basin are located in Xiaojinggu Town, Jinggu County, which mainly includes the sedimentary strata of the Mengyejing Formation, the Denghei Formation and the Mengla Formation. Due to the tectonic uplifting of the mountain in the late Cenozoic, the syncline structure caused the top of the Mengyejing Formation, the Denghei Formation and the Mengla Formation to be exposed to the surface. However, a complete sedimentary profile containing the middle and lower part of the Mengyejing Formation could not be obtained due to vegetation cover and village construction. The chronological study of sedimentary strata in the Simao Basin is mainly concentrated in the Mengyejing Formation with potassium salt. However, there still has significant controversy about the deposition time of this group at this stage. Recently, a continuous and complete high-resolution sequence (361.86 m in thickness) of the Mengyejing Formation was obtained through the continuous drilling. Among them, the Mengyejing Formation (0-353.3 m) is mainly a set of purple-red muddy silt and mudstone combination, while the underlying Mangang Formation (353.3-361.86 m) is a set of gray-white sandstone.

0 2019-11-25

Lithology description of a 300m-thick Oligocene borehole strata in the Qujing area, Yunnan

The thick Cenozoic sediments deposited in Yunnan are ideal achieves used to explore the history of local deformation process affected by the collision of the Indian-Eurasian plate as well as the evolution of the Indian monsoon in the Cenozoic. However, due to the lack of precise age control, the early Neogene strata in Yunnan are poorly constrained. The Qujing Basin in the northern part of Yunnan Province preserves thick and continuous Cenozoic sediments, which can be divided into the Xiaotun Formation, the Caijiachong Formation and the Ciying Formation from bottom to top. Through the combination of the field outcrop profile and the borehole core, the research team obtained the stratified stratum of the Xiaotun Formation and the Caijiachong Formation with a total thickness of 251 m in the Qujing Basin. The U-Pb geochronology of the top volcanic tuff layer (35.49 ± 0.78 Ma), Caijiachong mammal fossil group (late Eocene) as well as magnetic stratigraphy collectively reveals that the age at the bottom of the Xiaotun Formation is 46.2 Ma, the top of the Caijiachong Formation should be < 36.2 Ma, and the epoch line of the two groups is 41.2 Ma. However, due to the weak influence of tectonic activities in the late Cenozoic and the small deformation of the formation, the terrain in the middle of the basin is relatively flat, resulting in the inability to obtain the top of the continuous Caijiachong Formation and the upper Ciying Formation samples. A total of 320.1 meter core covering the entire Ciying Formation and the Caijiachong Formation was obtained through the continuous drilling mission carried out in the center of the basin. Among them, the overall lithology of the core of the Ciying Formation (0-216.3 m) is dominated by gray mudstone and siltstone, and several layers of coal seams are intercalated; while the lower Caijiachong Formation (216.3-305.5 m) is grayish and grayish green mudstone. The lithology of the Xiaotun Formation (305.5-320.1 m) is mainly dominated by red mudstone.

0 2019-11-25