Zhuangzhi Fm
Type Locality and Naming
It was named by the No. 1 Regional Survey Party under the Geological Bureau of Heilongjiang Province in 1974. The naming section is located on the No. 6 profile of West Hills of Zhuangzhi Township, Erlunchun Autonomous Banner of Inner Mongolia. The name of the formation was first cited publicly by the Compiler
Jingeng Sha (coordinator) Group for the Regional Stratigraphic Chart of Heilongjiang Province in 1979.
Lithology and Thickness
Composed of grey-green rhyolitic porphyritic ignimbrites, dacitic porphyrites, dacitic porphyrite-lithic crystal ignimbrites and andesitic porphyrites, intercalated with sandy conglomerates and tuffaceous breccias, with a thickness of over 1540 m.
Relationships and Distribution
Lower contact
It overlies unconformably the Proterozoic Erathem.
Upper contact
Not given. Regionally, the next younger unit is the Qilinji Fm (middle Jurassic conglomerate) in nearby Heilongjiang.
Regional extent
The formation is distributed in Zhuangzhi Township and to the west of Guyuan Township of Erlunchun Autonomous Banner, Inner Mongolia, as well as in the area extending from the Erqi region to the Chabayin River of the Wangfeng Township.
GeoJSON
Fossils
Age
Depositional setting
Additional Information
The Zhuangzhi Formation represents a set of volcanics formation and is similar to its nearby Xinganling Gr and Shangkuli Fm in their lithological characteristics and distribution. So, it has been decided the term “Zhuangzhi Formation” be used for the time being, and be assigned to the doubtful Early Jurassic Epoch, which awaits further investigations and study.
Uncertain; for graphic purposes, placed in column TJ8 as Sinemurian-Pliensbachian
Age span:
Beginning stage: Sinemurian
Fraction up in beginning stage: 0.0
Beginning date (Ma):
Ending stage: Pliensbachian
Fraction up in ending stage: 1.0
Ending date (Ma):
Depositional setting:
Depositional-pattern:
Additional Information
The Zhuangzhi Formation represents a set of volcanics formation and is similar to its nearby Xinganling Gr and Shangkuli Fm in their lithological characteristics and distribution. So, it has been decided the term “Zhuangzhi Formation” be used for the time being, and be assigned to the doubtful Early Jurassic Epoch, which awaits further investigations and study.
Compiler
Jingeng Sha (coordinator)