Gongyanghe Gr
Type Locality and Naming
No type section was assigned when the group was erected. An auxiliary section, the Taozizhai-Tashanshui section at Pingda Village in Pingda Township, southeastern Longling County, Yunnan Province was proposed by Zhang (1996) as representative section of the formation. The section lies about 40 km southeast of the seat of Longling County (98°59’ E, 24°20’ N), and is measured by the No 1 Yunnan Regional Geological Survey Team in 1966. The Gongyanghe Group was named by Yunnan Regional Geological Survey Team (1965). The name is derived from Gongyanghe River, a tributary of the Nujiang (Nu Kiang) River in the south of Longling County, Baoshan City, western Yunnan Province.
Synonym:
Lithology and Thickness
The Gongyanghe Group is a very thick suite of flysch-type epi-metamorphic rock series comprising epi-metamorphic sandstone and argillaceous slate. Lower part of the group consists of arkosic sandstone, arkose-quartzose sandstone, quartzose sandstone, and lithic arenite, intercalated with argillaceous rocks and thin-bedded crystalline limestone; Upper part consists of indurated mudstone alternated with sandstone and intercalated with chert or siliceous shale. In the reference section the group’s base is unexposed, and the group has an incomplete thickness of 7200 m.
Relationships and Distribution
Lower contact
The group’s base and underlying formation are unknown.
Upper contact
the group is in conformable contact with overlying Hetaoping Fm. The upper boundary of Gongyanghe Gr is defined by the lithologic change from indurated mudstone at the top of the group to the shale at the base of the Hetaoping Fm.
Regional extent
The Gongyanghe Gr is exposed in the Baoshan-Northern Tibet Region, distributed in Longling, Luxi, and Shidian counties, and Wanding Township, western Yunnan Province.
GeoJSON
Fossils
The group yields algae and trace fossil Paracruziana longlingensis in the lower part, and sponge spicule Protospongia from a number of horizons and micro-paleoplant fossils Asperatopsophosphaera, Baltisphaeridium, and Lophosphaeridium in the upper part.
Age
Depositional setting
The group belongs to flyschoid formation with huge thickness.
Additional Information