@article{oai:nagoya.repo.nii.ac.jp:00016153,
 author = {TAKEUCHI, Makoto and TSUKADA, Kazuhiro and SUZUKI, Toshiya and NAKANE, Yuki and GONCHIGDORJ, Sersmaa and NURAMKHAAN, Manchuk and KONDO, Tomoyuki and MATSUZAWA, Nozomi and NURAMKHAAN, Bakhat and SODNOM, Khishigsuren and GANTUMUR, Onon and KATSURADA, Yusuke and KAWAHARA, Kentaro and HASHIMOTO, Masami and YAMASAKI, Shoko and MATSUMOTO, Asuka and BORKHUU, Oyu-Erdene and MAGNAIBAYAR, Bulgantsengel and SYERYEKHAAN, Kundyz and LUVSANDORJ, Enkhchimeg and RANJIN, Ganzorig and GERELBAATAR, Myagmarsuren and OTGONBAATAR, Jamiyandagva and MUNKHJARGAL, Molomjamts},
 journal = {名古屋大学博物館報告},
 month = {Dec},
 note = {Recent mapping study in the Ulaanbaatar area has revealed that the geology around Ulaanbaatar previously reported should be revised in regard to stratigraphy and geological structure. Here, the new division of strata and geological structure are presented. Detailed field mapping with careful observation of sedimentary structures such as grading, loadcast, cross lamination, channel structure, and so on which indicate stratigraphic top have been carried out. The results show that many parts of strata were overturned and the geological structure is characterized with overturned folds with south vergence. In particular, the Paleozoic system is newly divided into two accretionary complexes (Altan-Ovoo & Orgioch-Uul Formation and Gorkhi Formation) and a shallow marine formation. Most of the previous shallow marine Carboniferous system is replaced by the two accretionary complexes and the shallow marine Carboniferous system which occurs with fossils indicating shallow sea environment only distributed in narrow area between two faults, although the latter has been regarded as extensively distributed around Ulaanbaatar. The geology suggests that the shallow marine sediments overlie the accretionary complex (Altan-Ovoo & Orgioch-Uul Formation), unconformably. The accretionary complexes are classified with quite different from the stratigraphy observed in clastic rocks. The Gorkhi Formation is composed of chert, siliceous shale and clastic rocks dominating massive and thick-bedded sandstone in ascending order. The Altan-Ovoo & Orgioch-Uul Formation consists of basalt, chert, siliceous shale and clastic rocks dominating thick- to thin-bedded sandstone and mudstone in ascending order. Furthermore, it is found out that the previous Gorkhi Formation in the northwest area and the previous Carboniferous system in the central south area are regarded as weakly metamorphosed and strongly deformed equivalents to the Altan-Ovoo & Orgioch-Uul Formation. Geological structure of these strata represents south vergence such as north-dipping thrust and fold-axial plane. The fact strongly suggests that north-directing subduction formed these geological structures.},
 pages = {1--18},
 title = {Stratigraphy and geological structure of the Paleozoic system around Ulaanbaatar, Mongolia},
 volume = {28},
 year = {2012}
}