1∶50 000 Geological Map Database of Sanchuan Map-sheet, Henan Province

The  1∶50  000  Geologic  Map  Database  of  Sanchuan  Map-sheet  (I49E013014), Henan Province (also referred to as the Database) was established using data obtained through practical  measurement  and  digital  mapping.  The  structural  and  lithologic  mapping  was conducted  during  field  data  acquisition,  focusing  on  the  presentation  of  special  geological blocks and informal mapping units. The samples collected in the field included 66 samples for microscopic petrography identification, 180 samples for whole-rock petrochemical analysis, 19 samples for isotopic dating, and 21 samples for chemical analysis in total. In this study, the main achievements obtained in this map-sheet are as follows. The Taowan Group was found to have occurred during the Ordovician according to multiple taxonomic classifications and short age ranges found in its stratotype section. Alkaline volcanic intercalations were found in the Taowan Group, indicating that an extensional basin developed on the southern margin of the North China Plate in the Ordovician. The greenschists in the Sichakou Formation and Xiewan Formation of the Kuanping Group were determined to be intraplate volcanic rocks, indicating that the main part of the Kuanping Group was formed in an extensional basin. The dike swarms of Silurian alkali-feldspar granite porphyry were found in the southern part of the map-sheet by mapping, restricting the closure era of the Qinling Ocean to a time not later than the Silurian. The  intrusions  of  the  late  Mesozoic  were  divided  into  five  intrusive  stages.  The  Luanchuan fault zone was determined to have undergone three stages of activities in the early Paleozoic, early  Mesozoic,  and  late  Mesozoic.  Furthermore,  Sinian  glacial  sediments  were  newly discovered in the map-sheet. The Database consists of data on feature classes, complex classes, and object classes, with a data size of about 63.5 MB. It fully reflects the geological and
mineral achievements of the map-sheet, and will provide basic data for mineral exploration and
exploitation and prevention and control of geological hazards in the map-sheet, research on the
Qinling Orogenic Belt, and the popularization of geoscience.