Tieshan Fm
Type Locality and Naming
The type section is located nearby Tieshan, 15 km southeast of Huixian County, Gansu. It was named by Ye Lianjun, Guan Shicong in 1944.
Lithology and Thickness
Limestone. Lower part, 246 m thick, is composed of medium-bedded to massive limestone intercalated with thin-bedded limestone and carbonaceous limestone and carbonaceous shale. Upper part, 340 m thick, is characterized by thin-slab-like limestone and clayey banded limestone intercalated with calcareous sandstone, shale and limestone with mud clasts. The thickness is 836 to 1391 m in Xunyang area, and 781 m in Songshuping area of Shanyang.
Relationships and Distribution
Lower contact
The formation conformably rests on the Yanglinggou Fm of Middle Devonian; younger (base-Frasnian) in the west, younger (to ca. mid-Frasnian) in the east.
Upper contact
The top is a conformable contact with the Lower Carboniferous (Yuanjiagou Fm?)
Regional extent
Tieshan Fm is distributed in central south Qinling, Huixian County to Chengxian County area.
East of Qinling, Xunyang area, the lithological character of Tieshan Fm is mainly composed of thin- to medium-bedded limestone and clayey limestone, intercalated with calcareous sandstone and sandy slate; the lower part yields coral and brachiopods fossils; and the upper part contains brachiopods and a few conodonts of Famennian.
GeoJSON
Fossils
The Lower part yields coral Disphyllum; the Upper part yields brachiopods Cyrtospirifer, Tenticospirifer, Yunnanella etc.
Age
Depositional setting
Additional Information