Damenglong Gr
Type Locality and Naming
Southwest corner of Yunnan. The Damenglong Gr was named by the Party of Regional Geological Survey; Yunnan Bureau of Geology in 1975. The type section is in Damenglong, Jinghong County, Yunnan Province.
Synonym: （大勐龙群）
Lithology and Thickness
In the typical section: Lower part of the group is composed of biotite plagioclase leptite ["leptite" = near obsolete term for fine-grained gneissic metamorphic rock; composed of feldspar and quartz with subordinate mafic minerals], gneiss, intercalated with mica schist, hornblende leptite, amphibolite, leuco-leptite and minor marble. Upper part is the interbedded mica-quartz schist and biotite-plagioclase leptite, sandwiched with magnetite leptite, hornblende leptite, leuco-leptite, marble and magnetite bed. All of the strata were migmatized (more strongly in the lower part). It is 1060 m thick.
Relationships and Distribution
Lower contact
The basement of the group is not seen.
Upper contact
Depending on location, the top is unconformably overlain by Neoproterozoic formations of the Lancang Gr, Pake Fm, Alaoshan Gr and Gaoligongshan Gr. All of those begin in mid-Tonian.
Regional extent
Widespread in west Yunnan; especially southwest corner of Yunnan. It is distributed mainly in the region from Yuxian County to Jinghong County, Yunnan Province.
GeoJSON
Fossils
Age
Depositional setting
From mindat.org: classic leptite has been interpreted as tectonized quartzo-feldspathic volcanic rocks
Additional Information