Lengbuzi Fm
Type Locality and Naming
The type section is located nearby Lengbuzi, 5 km north of Linjiang in Wenxian County, Gansu Province. It was named by Zhang Yan in 1961; Qin Feng and Gan Yiyan quoted it formally in 1976.
Lithology and Thickness
Quartz sandstone. The formation, 207 m thick, is composed of white, grayish-white and dark-gray thick-bedded quartz sandstone, chert-bearing quartzite intercalated with black shale and chert breccia. The quartzite possesses platy cross-bedding and ripple marks. Its lower part comprises more massive conglomerate beds.
Relationships and Distribution
Lower contact
The formation disconformably overlies on the Minbugou Fm.
Upper contact
Conformably overlain by the Shawan Fm.
Regional extent
The largest thickness can reach 207 m in Shawan to Lengbuzi areas; westwards, at Yangtanghe---Zhujiagou areas it thins to only 59-75 m thick; it is 188 m thick at Minbugou and 101 m thick at Huanglong in Songpan County.
GeoJSON
Fossils
It yields plant fossils: Lepidodendropsis cf. arborescens and Hostimella sp.
Age
Depositional setting
It is interpreted as a near-shore beach deposit.
Additional Information