Xushan Fm
Type Locality and Naming
Northwest Henan. The Xushan Fm was named by the Party of Regional Geological Survey, Henan Bureau of Geology in 1965. The naming section is located at Sandanhe- Jianhumen, Beizhai in the juncture zone between Shaoyuan Township, Jiyuan County, Henan and Tongshan Township, Yuanqu County, Shanxi Province. The formation belongs to the lower part of the Xiong'er Gr. Synonym: Lower Andesitic-porphyrite Fm, Lower Xiong'er Gr, Lower Xiong'er Fm, Zhanghemiao Fm and Fudian Fm are all the different names for Xushan Fm. (3/4) formation in the Xiong'er Gr.
Synonym: （许山组）
Lithology and Thickness
The Xushan Fm is composed of andesite, pyroxene andesite, andesitic basalt, sandwiched with rhyolite and volcaniclastic rock. It is characterized by rich plagioclase megacrysts, pyroxene and several layers of volcaniclastic rocks sandwiched in the formation. The basal part is intercalated with extremely small amount of feldspar-quartz sandstone and purple-red shale. The formation is 2964 m thick.
Relationships and Distribution
Lower contact
It is in conformable contact with the underlying Dagushi Fm or is in unconformable contact with the underlying Taihua Gr of Archean.
Upper contact
It is in conformable contact with Jidanping Fm.
Regional extent
NE Shaanxi-NW Henan-S. Shanxi. The formation is distributed in Jiyuan, Luanchuan, Luoning, Lushi and Lushan counties. The thickness varies from 2400 to 3000 m and is thinned from northwest to east, for example it is 2874 m thick in Luoning County, 2557 m in Yiyang County, but only 481 m thick in Qinyang County.
GeoJSON
Fossils
Age
Depositional setting
Additional Information