China Geological Survey: 1:50 000 Geological Map of Hadatu Map-sheet (K50E004023), Inner Mongolia

The 1: 50 000 Geological Map of Hadatu Map-sheet (K50E004023), Inner Mongolia was compiled in accordance with the “Technical Requirement for Regional Geological Survey (1: 50 000)” (DD2019−01), employing geological mapping techniques and methods in shallow overed areas. It was completed by fully leveraging the outcomes of 1:200 000 and 1:250 000 regional geological surveys, in conjunction with geophysical, geochemical, remote sensing, and drilling data. This survey integrated remote sensing, shallow drilling, and surface geological investigations to detail 15 Quaternary genesis types and identify 12 active faults. A late Pleistocene large paleolake (153~71 Ka BP) was newly identified, and the map expressed three levels of lacustrine terraces, discovering a late mammoth-woolly rhinoceros fauna and Neolithic ancient cultural layer in the sedimentary layer of the level II terrace of paleolake. Investigations of the paleolake expansion-contraction polycycle sediments confirmed that the paleolake completely recorded the last interglacial climate event (MIS5 128~75 Ka BP). Comparative studies of the Quaternary in the Xar Moron River basin established a climatic framework for the Horqin Sandy Land in the past 170 000 years, constructing three phases of desertification expansion in the Horqin Sandy Land since the late Pleistocene. The database, formatted in DGSDIS, includes 6 rock mapping units, 15 Quaternary genesis mapping units, and 5 volcanic eruption events. It contains 174 pieces of geological polygon data, 427 pieces of geological boundaries data, 23 pieces of drilling data, 29 pieces of attitude data, 89 pieces of sample data, 3 pieces of zircon U-Pb dating data, and 9 pieces of optically stimulated luminescence (OSL) dating data, totaling 313 MB of data. This survey has achieved a series of original results, exploring mapping methods for the Horqin Sandy Land overburden area and serving as a model for geological surveys in overburden areas. The database comprehensively records the foundational data of the survey work and systematically expresses the new findings obtained from this investigation. The data is accurate, detailed, rich in information, and conveniently and quickly retrievable, providing foundational geological information for basic geological surveys, national spatial planning, geohazard prevention, ecological civilization construction, and construction projects.