Abstract:
In this paper, the database of 1∶50 000 mineral geological map of Changtuxilesitai Map-sheet (L50E015021), Inner Mongolia (also referred to as the Database) was established on the basis of digital geological mapping system, achieving the digitalization of the whole process of early data preparation → field geological mapping → indoor comprehensive data collation → the presentation of final results. Meanwhile, various relevant data were effectively described, stored, organized and utilized in an integrated way. The mapping method of “volcanic structure–lithology and lithofacies–volcanic strata” was adopted during the establishment of the Database. As a result, the volcanic strata were determined again, and the volcanic lithofacies as well as eruption cycles and their association types were classified in detail. Furthermore, the relationship of volcanics, volcanic structures and volcanic activities with mineralization were ascertained, and the geological conditions and metallogenic rule of metal minerals in Mesozoic volcanic areas were summarized. The Database contains eight stratigraphic units, four phases of volcanic eruption cycles, eight mineralization prospecting areas and six prospecting target areas. In addition, it also contains analytical data on 1170 pieces of rock samples and 261 pieces of samples for geochemistry, 108 pieces of samples for petrochemistry, 222 pieces of thin slice samples for petrography, 35 pieces of S and Pb isotopes, ten pieces of H and O isotopes, as well as four zircon U–Pb ages. The newly discovered Changtuxili Ag-Pb-Zn-Mn deposits in the map-sheet area have a roughly identified resource of 1028.35 tonnes of 334
1 Ag, 112500 tonnes of Pb, 93600 tonnes of Zn and 552400 tonnes of Mn, belonging to a large-scale silver polymetallic deposit. The Database is detailed and accurate in contents and boasts high utility, providing important basic data for further survey and assessment of mineral resources, as well as the exploration and development of metal minerals in the area of Mesozoic volcanic rocks in the middle–southern section of the Da Hinggan Mountains.