1∶50 000 Geologic Map Database of the Xiaoshui Map Sheet, Henan Province

The 1∶50 000 geologic map of the Xiaoshui map sheet (I49E016015), Henan Province was prepared by using the digital mapping technology and database building, during which existing geologic and mineral data were fully collected and comprehensively analyzed. The database of this geologic map (also referred to as the Database) is in the format of MapGIS and covers nine stratigraphic units and six stages of magmatic events, which also includes electronic probe data of 70 samples, chemistry testing data of 57 samples, zircon U-Pb dating of 73 samples and whole-rock geochemical data of 147 samples, coming to a total data size of 31.9 MB. Meanwhile, the new mapping theory and methodology based on orogenic belts were adopted to highlight tectonic and lithologic mapping as well as the presentation of special geologic bodies and informal mapping units. In this way, the contents on the map face were expressed in a more scientific, readable and practical manner. In this study, the structure of the North Qinling Orogenic Belt (NQOB) was established, consisting of the Shangnan-Danfeng tectonic belt, Zhu-Xia ophiolitic mélange belt, Qinling microcontinent and Erlangping island arc, a back-arc basin. Following this, it was clear that the Zhu-Xia ophiolitic mélange belt was formed in the early Paleozoic era. Furthermore, the composition and four stages of fold deformations of the Qinling Group were ascertained; the spatial distribution law, protolith and metamorphic era of the high and ultrahigh-pressure rocks in the map sheet area were determined. Thus, revealing that the whole Qinling microcontinent was involved in the early Paleozoic orogen and had undergone great transformation. The achievements of this study have provided new basic geological data for the preparation of the ‘Annals of Geology of Henan Province’ and the projects funded by the ‘Geological Exploration Fund of Henan Province’. Moreover, the 1∶50 000 geologic map of the Xiaoshui map sheet was awarded the ‘Excellent Map Sheet Prize’, among the areas mapped, based on orogenic belts in the national regional geological surveys of China in 2018.