Karakul lake is the distal proglacial lake of the Muztagh Ata glaciers in Xinjiang, and its material input is mainly affected by glacier changes. The Karakul lake sediment core was drilled in the deepest part of the Karakul Lake (38 ° 26.56 ′ N, 75 ° 03.65 ′ E, water depth of 19m) in June and July, 2013, by the research group of prof. Xubaiqing, Institute of Tibetan Plateau Research. The length of the sediment core was 14.16m. This data set is the geochemical data of the lake sediment core, providing high-resolution (0.2mm) information of geochemical elements' contents. The element data was obtained using the nondestructive X-ray fluorescence (XRF) measurements (Itrax Core Scanner, Sweden). The measurement was performed in the Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Chinese Academy of Sciences. The element content in this data set changes obviously, among which the Zr element, Zr/Rb ratio and Rb/Sr ratio provides the long-term glacier change history in Muztagh Ata region, while Ti element provides the dust change history. These data are of great scientific significance for studying the long-term paleoclimate and environmental change histories in the the westerly-dominated region.
This data includes 50 14C dating data of 5 Lake cores (ANGREN jincuo, Yilong lake, guozhaco, bangdaco and gongzhucuo). The age control of lake sediment cores depends on radiocarbon isotope (14C) dating. The chemical treatment and analysis test of this batch of samples were completed in Miami beta laboratory and Peking University in the United States. The test time was 2018-2022. The test process was carried out in strict accordance with relevant standards. The data sheet includes the lake core sample number, laboratory sample number, dating sample depth, 14C dating results, dating error and corrected results, etc. Good chronological control is the basis of paleoenvironmental reconstruction.
Paleoecological and paleolimnological studies can provide a long-term perspective on changes in environmental and ecosystem processes. The sediments documented both direct and indirect impacts of climate change and human activities on aquatic ecosystems. The fossils of zooplankton remain and pigments in lake sediments can reflect community structure changes of primary producers and primary consumers. The authors reconstructed the zooplankton and algal community changes during the past 600 years using carapaces of A. tibetiana and resting eggs of D. tibetana and pigments from the sediments of Dagze Co, in the central Tibet Plateau. Using total nitrogen and total phosphorus reconstructed the nutrient changes. These results suggest that algal community structure and changes in production can be attributed to alterations in the zooplankton community, with important implications for Tibetan aquatic ecosystems.
This data including the GDGTs data and fatty acid data records of Xiada Co in the west of Qinghai Tibet Plateau during the past 2000 years. These data are obtained by the research team using organic geochemical methods. The Xiada Co sediment core was collected in the summer of 2014. The water depth of the sampling point (33.392°N、79.363°E，4373m) is about 19m. The extraction of biomarkers in lake sediments was carried out by ultrasonic extraction. The extraction and testing of compounds were carried out in the laboratory of environmental change and surface processes, Institute of Qinghai Tibet Plateau, Chinese Academy of Sciences. The detection instrument of wax fatty acid compounds in sediments is gas chromatography flame ion detector (GC-FID, model: Agilent 7890a). The test instrument for GDGTs compounds is HPLC-APCI-MS (Agilent 1200 HPLC + 6100 MS), which is tested by three chromatographic columns in series. The model of chromatographic column is (hypersil gold silica, 100 mm) × 2.1 mm, 1.9 μ m). 5-methyl bgdgts isomer and 6-methyl bgdgts isomer were effectively separated by silica gel column in series. This data can provide the climatic and environmental background of human activities in the western plateau of the late Holocene, provide a basis for understanding the process and mechanism of climate change in the western Qinghai Tibet Plateau in the past 2000, and provide boundary conditions for climate simulation.
The present data are chronological and palynological data from the Luanhaizi Lake core in the Menyuan Basin, northeastern Tibetan Plateau. We used the AMS14C method to test nine dated samples from the LHZ18 core. Bulk samples were collected from plant remains and organic-rich horizons from the core LHZ18 for accelerator mass spectrometry (AMS)14C dating. Samples were measured at Beta Labs in the USA and Lanzhou University.Pollen analysis was completed at the Key Laboratory of Western China’s Environment Systems,Ministry of Education, Lanzhou University, with 140 stratigraphic pollen samples and 10 topsoil pollen samples. Spore pollen identification statistics were carried out under a light microscope.The pollen results mainly include the number of grains of trees, shrubs, herbs and aquatic plants.
Luanhaizi Borehole (LHZ18) was acquired by Huang Xiaozhong Research Group of Lanzhou University in August 2018. This data is 0-859 cm grain size data of the core of Luanhaizi Lake in Qilian Mountains. Grain size analysis was carried out at 0-4 m according to one sample, and grain size analysis was carried out at on ssample interval at the depth of 4-8.6 m, totaling 390 data were obtained. The experiment was completed in the Key Laboratory of the Ministry of Environmental Education of Lanzhou University, and grain size analysis was carried out with Mastersizer 2000 instrument. The data reflected the grain size change of the lake sediment, which is very important for the study of long-time series eolian activities in the Qinghai-Tibet Plateau.
This data set contains the elemental geochemical composition data of the surface sediments of 18 lakes in the two lakes area of the Qinghai Tibet Plateau, including qiaguiacuo, tongcuo, yueqiaco, Grenco, Cuona, nurmacuo, dazzcuo, saibucuo, bamucuo, gemangcuo, naripingcuo, pengcuo, darucuo, mudidaryucuo, cuoe, Jiangcuo, guomangcuo and zhangnaicuo. It includes Al, Ba, be, CA, Fe, K, Mg, Mn, Na, P, Sr, Ti, V, Zn, Cr, Co, Ni, Cu, as, Mo, CD, Sb, Tl, Pb, TOC and TN data. The data were collected by ICP-AES, ICP-MS and elemental analyzer of State Key Laboratory of lake and environment, Nanjing Institute of geography and lakes, Chinese Academy of Sciences. The standard deviation of repeated measurement was less than 5%. The data set reflects the chemical properties of the sediments in the two lakes, and can be used to establish the conversion equation for quantitative reconstruction of Lake Sediment Salinity, evaluate the ecological risk of the lake and identify the impact of human activities.
In 2017, 27 surface sediments were collected in Qinghai Lake by gravity sampler, and the top 1cm was taken as the surface layer, which was freeze-dried and ground into powder after being taken back to the laboratory. Before testing the content of organic carbon and nitrogen, 1mol / L hydrochloric acid should be used to stir the reaction for more than 10 hours, so that the carbonate is completely removed, then dried and ground, and the organic carbon and nitrogen are tested on the element analyzer. The total inorganic carbon content is the carbonate content of the whole rock powder sample measured by infrared spectrum, which is then calculated as the total inorganic carbon content. The contents of organic carbon and inorganic carbon constitute the total carbon content of the lake, and they are close to each other, indicating that the inorganic carbon burial flux and organic carbon burial flux of Qinghai Lake are similar.
Paleo-shorelines are widely developed in the lakes of the Tibetan Plateau (TP), which record the history of paleo-lake level changes. The development age of the mega-lake represented by the highest paleo-shoreline is controversial. The age of the shoreline or the mega-lake can be obtained by measuring the burial age of the shoreline sand in the sedimentary strata of the paleo-shoreline by using the optical stimulated luminescence (OSL) dating technology. This data includes the OSL ages of the highest paleo-shorelines of three lakes in the northwestern TP. The dating is based on the K-feldspar pIRIR method developed in recent years, which effectively solves the problem that the quartz OSL signal is not suitable for dating in the study area. This data can provide key information for the evolution history of the mega-lakes on the TP.
In the summer of 2019, the surface sediments of Nam Co, Wuru Co, Gren Co, Qiago Co, Dazz Co, Saibu Co, Gomang Co, Guomang Co, Bamu Co, Nurma Co, Nariping Co, Zhi Co, Jiang Co, Daru Co and Yueqia Co lakes in Nam Co and Siling Co area were collected by grab. The lake sediments were brought back to the laboratory and frozen, and then put into the freeze dryer for freeze drying, The freeze-dried samples were ground to powder by agate mortar, and then the samples were tested by XPert3 Powder X-ray diffraction method. Based on the analysis of Highscore Plus0 software, the content of each major mineral was obtained. The results show that the main minerals in this area are stalagmite, aragonite, calcite and illite.