The modern sporopollen identification results of five different geomorphic types in the middle reaches of Heihe River show that there are 39 sporopollen types, 22 main types, belonging to 6 different vegetation types in 45 topsoil samples distributed in the desert vegetation belt. The SPOROPOLLEN ASSEMBLAGES with high percentage of sporopollen in the sporopollen map were selected to represent different geomorphic types. It was found that five geomorphic types (dune, alluvial proluvial fan, flood plain, riverbed and wetland) could be expressed by different combinations of nine sporopollen.
This data set contains a deep drilling paleomagnetic age data near the open sea in the middle reaches of Heihe River. The borehole is located at 99.432 E and 39.463 n with a depth of 550m. The samples of paleomagnetic age were taken at the interval of 10-50 cm. The paleomagnetic test was carried out in the Key Laboratory of Western Ministry of environmental education of Lanzhou University. The primary remanence of the samples was obtained by alternating demagnetization and thermal demagnetization, and the whole formation magnetic formation was obtained by using the primary remanence direction of each sample, and then the sedimentary age of the strata was obtained by comparing with the standard polarity column. The results show that the bottom boundary of the borehole is about 7 Ma and the top boundary is 0 ma.
Since the formation of Heihe River, sporopollen data samples have been collected from the drilling strata of Da'ao well in the middle reaches of Heihe River. Drilling location: 39.491 n, 99.605 E. The drilling depth is 140 meters. 128 samples of sporopollen are collected from top to bottom. At present, there are 19 data of sporopollen results, which are distributed in each sedimentary facies from top to bottom. The sporopollen samples were removed from carbonate, organic matter, silicate and other impurities in the laboratory, and the species and data of sporopollen were identified under the microscope. Sporopollen results mainly include the percentage content and number of trees, shrubs, herbs, aquatic, ferns and other families and genera.
Based on the study of the terrace formation age in the upper reaches of heihe river, photoluminescence samples were collected from the sediments of grade 6 river terrace near the upper reaches of qilian river.The quartz particles (38-63 microns) in the sample were isolated in the laboratory, the equivalent dose and dose rate in the quartz particles were measured, and the photoluminescence age of the sample was finally obtained.The obtained ages range from 5ka to 82ka, corresponding to the years of cutting down the terraces of all levels.
Since the formation of heihe, palynology data samples were collected from the borehole formation of dasunken well in the middle reaches of heihe.Borehole location: 39.491 n, 99.605 e.The borehole has a depth of 140 meters and 18 palynological samples are collected from top to bottom. Currently, there are 3 palynological results, which are distributed in each sedimentary phase from top to bottom.Impurities such as carbonate, organic matter and silicate were removed from palynology samples in the laboratory, and the palynology types and data were identified under the microscope.Palynology results mainly included the percentage and number of trees, shrubs, herbs, aquatic and ferns.
This dataset is collected from the Supplementary Materials part of the paper "Chen, F.H., Dong, G.H., Zhang, D.J., Liu, X.Y., Jia, X., An, C.B., Ma, M.M., Xie, Y.W., Barton, L., Ren, X.Y., Zhao, Z.J., & Wu, X.H. (2015). Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 BP. Science, 347, 248–250.". In this paper, researchers analyzed animal bones, plant remains and other artefacts from 53 sites across the northeastern Tibetan plateau and found that humans began to relocate to the elevations above 4000 masl after the emergence of Barley. According to the study, the prehistoric human expansion into the higher, colder altitudes of the Tibetan plateau took place as the continental temperatures had themselves become colder after 3,600 calendar years before the present, thus, the key impetus of the expansion was agricultural innovation rather than climate change. This dataset contains 4 tables, table names and content are as follows: Data list: The data name list of the rest tables; t1: Calibrated radiocarbon dates and domesticated plant and animal remains from sites investigated on the NETP; t2: Radiocarbon dates of the Paleolithic sites on the Tibetan Plateau; t3: OSL dates of the Paleolithic sites on the Tibetan Plateau. See attachments for data details: Supplementary Materials.pdf, Agriculture Facilitated Permanent Human Occupation of the Tibetan Plateau after 3,600 BP.pdf.
The application of general circulation models (GCMs) can improve our understanding of climate forcing. In addition, longer climate records and a wider range of climate states can help assess the ability of the models to simulate climate differences from the present. First, we try to find a substitute index that combines the effects of temperature in different seasons and then combine it with the Beijing stalagmite layer sequence and the Qilian tree-ring sequence to carry out a large-scale temperature reconstruction of China over the past millennium. We then compare the results with the simulated temperature record based on a GCM and ECH-G for the past millennium. Based on the 31-year average, the correlation coefficient between the simulated and reconstructed temperature records was 0.61 (with P < 0.01). The asymmetric V-type low-frequency variation revealed by the combination of the substitute index and the simulation series is the main long-term model of China's millennium-scale temperature. Therefore, solar irradiance and greenhouse gases can account for most of the low-frequency variation. To preserve low-frequency information, conservative detrended methods were used to eliminate age-related growth trends in the experiment. Each tree-ring series has a negative exponential curve installed while retaining all changes. The four fields of the combined 1000-yr (1000 AD-2000 AD) reconstructed temperature records derived from stalagmite and tree-ring archives (excel table) are as follows: 1) Year 2) Annual average temperature reconstruction 3) Reconstructed temperature deviation 4) Simulated temperature deviation
Natural changes and human impacts of typical karst environments in historical periods: stalagmite recording project is a major research program of "Environmental and Ecological Science in Western China" sponsored by the National Natural Science Foundation of China. The person in charge is Tan Ming, a researcher at the Institute of Geology and Geophysics, Chinese Academy of Sciences. The project runs from January 2002 to December 2009. The temperature data of Beijing hot months (May, June, July and August) in 2650 (665 B.C.-A.D. 1985) are the results of the project. The data are reconstructed according to the correlation between the annual thickness of stalagmites in Shihua Cave in Beijing and meteorological observation data. The temperature signals reflected by soil carbon dioxide and cave dripping are amplified by the soil-organic matter-carbon dioxide system and recorded by the annual sequence of stalagmites. Although the general trend of temperature has decreased in recent thousands of years, the reconstructed temperature reveals that the climate has experienced repeated rapid warming on a century scale. This result is related to other records in the northern hemisphere, indicating that there is a hemispheric influence on the periodic changes of temperature in the sub-millennium scale. The data contains a txt file with attribute fields such as yr.AD, layer number, original thickness (um), maximum error in um (+-), sedimentary trend, detrended thickness (um), reconstructed temperature, maximum error in degree C (+ -), temperature anomaly, temperature anomaly + error, temperature anomaly-error, maximum error in age (yr. +-).
According to the formation age of the river terraces in the upper reaches of the Heihe River, the Optically Stimulated Luminescence dating analysis was performed on the sediments of Heihe terrace. The samples were mainly fluvial sand reservoirs, and the measuring object was quartz grains in sand. The formation age of the 6th-order terrace near Qilian in the upper reaches of the Heihe River was measured by Optically Stimulated Luminescence dating. The terrace age results showed that the terraces were mainly formed since the late Pleistocene (60ka-7ka). The sample sites of the chronological data are distributed near the mainstream of the Heihe River in the northwest of Qilian County in the upper reaches of the Heihe River.
Data content: Standard ring-width chronology derived from Wilson juniper shrub around the northern shore of the Nam Co Lake; May-June SZI (Standardized Moisture Anomaly Index) drought reconstruction for the Nam Co region. Time span: 1605 to 2010. Temporal resolution: Yearly. Application and prospects: Hydroclimate study on the south-central Tibetan Plateau.