Lazhuhe Fm
(68), Capitanian Stage (late Guadalupian Epoch; late-Middle Permian)
Type Locality and Naming
The type section is located in the area of the Lazhu River, Lanping County, Yunnan Province (99°07′, 26°45′). It was named by the Yunnan Provincial Bureau of Geology and Mineral Resources in 1990.
Lithology and Thickness
Limestone and Sandstone. Lower part is composed of grey thick-bedded limestone and bioclastic limestone, intercalated with marls, with the black slate at its base being intercalated with lenticular coals. Upper part of the formation is composed of grey-yellow and brown-yellow medium-bedded sandy conglomerate, quartz-sandstone and lithoclast-rich quartz-sandstone, intercalated with grey-black clayey slate, lime-slate and clayey limestone lenses.
Relationships and Distribution
Lower contact
Disconformable contact with the underlying Carboniferous strata. Regionally, the next older unit is the mid-Permian Gaojingchao Fm.
Upper contact
Regionally, the next younger unit might be the Lazhuhe Fm.
Regional extent
Distributed in the areas of Lazhu River of the Lanping County, Laogongzhai of Simao City and Mengkuang of the Lancang County in a NWW-trend. The thickness of the formation is increasing from west to east and from south to north in a range of 228.9-771.2 m. In the area of the Lazhu River of the Lanping County in the northern part of the region the thickness of the formation is of 467 m. In the Mongya area of the Yunxiao County the formation is composed of grey and grey-black sandy shale and shale, intercalated with cherty limestone, with a thickness of 600 m. In the area of the Laogongzhai of Simao City the lower part of the formation is composed of sandstone and siltstone, intercalated with carbonaceous siltstone, and its upper part is composed of siliceous nodule-bearing micrite, with a thickness of 228.9 m. In the Mengkuang area of the Lancang County the formation is composed largely of limestone, intercalated with a small amount of clayey limestone and calcareous siltstone, with a thickness of 458.9 m.
GeoJSON
Fossils
Yields fossils such as Fusulinida represented by Metadoliolina lepida, Sumatrina longissima and Yabeina sp.; Corals represented by Wentzelella salinaria, as well as bivalves and plants, etc.
Age
Depositional setting
It is interpreted as shallow-sea continental-shelf carbonate and clastic deposits.
Additional Information