Maerzheng Fm
(32), mid-Middle Permian
Type Locality and Naming
The type section is located in the Ma’erzheng-Shuweimenke area of the Dulan County, Qinghai Province. It was named by the Qinghai Provincial Bureau of Geology and Mineral Resources in 1991. Upper formation in Buqingshan Gr.
Synonym: Ma'erzhang Fm
Lithology and Thickness
Sandstone and Limestone. Lower part is composed of grey-green pebble-bearing feldspathic lithoclastic sandstone, meta-basalt and siliceous rocks. Its basal part consisting of grey-green pebble-bearing sandstone and being intercalated with the meta-basaltic and lithoclastic sandstones. Upper part is composed of grey thick-bedded and massive limestones, as well as bioclastic limestone. Thickness is 4692 m.
Relationships and Distribution
Lower contact
Conformable contact with the bioclastic rocks and limestone of the underlying Shuweimenke Fm.
Upper contact
Unconformable contact with sandy conglomerate of the overlying Weiming Fm (not in Lexicon or in Geol. Formation Names of China (Springer); therefore labeled as "unnamed conglomerate". Next younger regional unit is the Hongshuichuan Gr of basal Triassic.
Regional extent
Distributed in the Nanshan Mt. of the Xueshui River area.
GeoJSON
Fossils
Fusulinida represented by the Neoschwagerina-Eopolydiexodina assemblage zone. In the Nanshan Mt. of the Xueshui River area the formation yields Brachiopods represented by Haydenella chilianschaniana, Martinia orbicularis, etc.,
Age
Depositional setting
It is interpreted as deep-sea slope deposits.
Additional Information