Shimen Fm
Type Locality and Naming
Northeast Liaoning. The Shimen Fm was named by the No. 9 Party of Geology, Liaoning Bu-reau of Geology and Mineral Resources in 1986. The type section is in Baijiajie, Dadianzi Township, Tieling County, Liaoning Province. Middle (4 of 6) formation of Shyatun Gr.
Synonym: （石门组）
Lithology and Thickness
The Shimen Fm is subdivided into three parts. Lower part is composed of banded slate, fine-crystalline dolomite and laminated (banded) dolomite, coarse quartz sandstone. Middle part consists of quartz psammitic dolomite, medium- to coarse-grained, pebbly ferruginous quartz sandstone, silty fine-crystalline dolomite, banded silty slate. Upper part is thick-bedded laminated fine-crystalline dolomite, laminated slate, while its top consists of thick-bedded laminated fine-crystalline dolomite. The Shimen Fm is 867 m-1497 m thick.
Relationships and Distribution
Lower contact
It is in conformable contact with underlying Erdaogou Fm.
Upper contact
Conformably overlain by the Songjiagou Fm
Regional extent
Northeast Liaoning. It is widely spread in Fanhe River drainage area. It is stable in lithological character in lateral direction but changeable in thickness, for example, 1497 m thick in Houshijiawaizi, Tieling County, but only 358 m thick in Erdaogou, Tieling County.
GeoJSON
Fossils
The stromatolites occurring in middle and upper parts are Conophyton lituum, Colonnella cormosa, Pseudogymnosolen cf. mopanyuense etc.
Age
Depositional setting
Additional Information