Hangaoshan Gr
Type Locality and Naming
The Hangaoshan Gr was named by E. Norin in 1924. The type section is in Hangaoshan Mountain, southeast of Linxian County, Shanxi Province.
Synonym: （汉高山组）
Lithology and Thickness
Central-West Shanxi. In the type section, the formation is composed of coarse clastic rock of fluviatile facies, and subdivided into three formations. Lowest formation is composed of purple-red to grey-yellow conglomerate, pebbly sandstone, arkosic sandstone, sandy shale and shale, sandwiched with andesitic tuff, 135 m thick. Middle formation is yellow pebbly arkosic sandstone, sandwiched with grey-purple, yellow-green shale and arkosic sandstone, 105 m thick. Upper formation consists of grey-yellow conglomerate, white quartz sandstone and purple-red shale with amygdaloidal and massive andesite, 40 m thick. Sedimentary breaks are recognized between the three formations.
Relationships and Distribution
Lower contact
The base of the Hangaoshan Gr is in unconformable contact with the underlying Jiehekou Gr or the Luliangshan Gr of Archean.
Upper contact
The top is unconformably overlain by the Huoshan sandstone of Cambrian.
Regional extent
Central-West Shanxi. The Hangaoshan Gr spreads sporadically and exposed in limited range, e.g., in Hangao Mt. It is exposed only in an area of 5 km2, while 3.5 km2 in Xiaoliangling, Baijiatan Loufan County, but in Guankou region it is not exposed on the land surface, As inferred on the basis of geophysical prospecting data, it covers an area about 20 km2. The andesite found in Xiaoliangling range, Loufan County, shows black-green, purple-red color and massive, amygdaloidal structure. The preserved thickness is recorded at 380 m. A volcanic rock, 255 m thick, recognized in a borehole set at Guankou north of Taiyuan City is the dark-colored andesitic basalt in the lower part with amygdaloidal structure, and the grey-green, purple-red dacitic rhyolite in the upper part. According to the Shanxi Province Party of Regional Geological Survey, the above-mentioned volcanic rocks both in Xiaoliangling and Guankou areas are equivalent to the third formation in the Hangaoshan section.
GeoJSON
Fossils
Age
Depositional setting
Additional Information