Luolou Gr

The type section is located at the east slope of Naliling 1 km northeast of Luolouxu (about 60 km from the east of the county seat) in Lingyun County, Guangxi. It is firstly named by Zhang Wenyou as "Luolou bed" in 1952. The reference section is located along the road near the government office of Jinya town, Fengshan County, Guangxi. [Schematic stratigraphic columns seem to suggest that it consists of a lower Majiaoling Fm and an upper Beisi Fm.]

Synonym: Since Zhang Wenyou (1952) first publicly introduced the "Luolou bed", in 1959 Zhao Jinke recounted in the "Lower Triassic Ammonoids in Western Guangxi": in "Guangxi Stratigraphic Table" by Li Siguang, Zhao Jinke, and Zhang Wenyou (1941), the Lower Triassic in the Lingyun area was once named "Luoshuo", which is cited in all the literature discussing the Luolou group (group) after that. In fact, "Guangxi Stratigraphic Table" does not have the name "Luo Floor". In this book, Li Siguang et al. (1941) named the Lower Triassic in the Lingyun area as "Bagenghui Shale". In 1962, Zhao Jinke and others renamed the "Luolou Bed" to the Luolou group to represent the early Triassic clastic deposits in western Guangxi.

It is dominated by mudstone to shale with a small amount of siltstone, fine sandstone, argillaceous limestone and limestone. Sometimes interbedded with siliceous rock, siliceous shale and conglomerate. The reference section is 61 m thick. The thickness varies greatly, generally ranging from 127 to 429 m, and Wuming Lingma can be as thick as 1114 m. In Tiandong and Fengshan, the thickness is small, only tens of meters or more than 100 meters.

Nine ammonoid zones were established from lower to upper parts of this formation: 1. Ophiceras sinensis Zone, 2. Vishnuites marginalis Zone, 3. Proptychites kwangsiensis Zone, 4. Koninckites lingyunensis Zone, 5. Owenites costatus Zone, 6. Pseudowenites oxynostus Zone, 7. Tirolites darwini Zone, 8. Columbites costatus Zone, 9. Procarnites oxynostus Zone. Nine conodont zones were established from lower to upper parts of this formation: 1. Hindeodus minutus acme zone, 2. Hindeodus parvus acme zone, 3. Isarcicella isarcica range zone, 4. Neogondolella carinata range zone, 5. Neospathodus dieneri assemblage zone, 6. Neospathodus cristagali-Platyvillosus costatus assemblage zone, 7. Neospathodus waageni zone, 8. Neospathodus homeri-N. triangularis assemblage zone；And bivalves: Pseudoclaraia wangi and Claraia griesbachi

Shallow marine facies