Kongshuhe Fm
Type Locality and Naming
The type section is located in the area of the Kongshuhe Village, Tengchong County, Yunnan Province. It was named by the Regional Geological Reconnaissances Party of Yunnan Province in 1985.
Lithology and Thickness
Clastics and Limestone. Sandy clayey carbonate; with Lower part being mainly clastics and Upper part being mainly limestone. Yields abundant fossils. Thicknesses range from about 230 to over 520 m (see Regional extent).
Relationships and Distribution
Lower contact
Disconformable contact with the underlying Menghong Gr locally (see Regional extent)
Upper contact
Disconformable contact with the overlying dolomitic limestone and normal limestone of the Dadongchang Fm (see Regional extent)
Regional extent
Distributed in the Gudong, Mingguan and Qiaotou areas to the north of Tengchong County Town with a complete stratigraphic sequence, while to the south of Tengchong County Town the exposed stratigraphic sequence of the formation has been destroyed by faults to become an incomplete one. The regional lithology of the formation is relatively stable. In the area of the Kongshuhe Village of the Mingguan region, the Lower part of the formation is composed of sandy conglomerate, pebble-bearing sandstone, with a gradual upward transition to siltstone, siltstone and sparry bio-limestone, and is in a disconformable contact with the underlying Menghong Gr, with no top having been found, and with a thickness of 485.4 m. In the area of Dashuigou at Qiaotou there is no base of the formation having been found, with its Lower part being composed mainly of shale (or siltstone), and with its Upper part being composed of light-purple and light-grey thick-bedded sparry bio-limestone; it is in a disconformable contact with the overlying dolomitic limestone and normal limestone of the Dadongchang Fm, with a thickness of over 526 m. In the Shuangheyan area to the south of Tengchong County there are exposed only the middle and upper parts of the formation, which are composed of silty slate, sparry bio-limestone and crystalline limestone, with a thickness of 234.3 m. The contact relationship between the formation and its overlying Dadongchang Fm is unknown because of the intrusion of granite.
GeoJSON
Fossils
The clastic rocks in the Lower part of the formation yields Brachiopods such as Spiriferella rajah, Spirifer malayensis, Costiferina alata, Stepanoviella aff. gracilis; Bryozoans such as Fenestella elusa; Trilobites such as Phillipsia sp., and Bivalves, etc.
The limestone in the Upper part of the formation of yields Fusulinida as represented mainly by Triticites cf. liuchowensis and Quasifusulina, associated with bryozoan, brachiopods and Foraminifera.
Age
Depositional setting
Additional Information
GeoJSON estimate by Runan Yong, Suxiao Li and Wen Li (Chengdu Univ. Tech. students)