Jinghezhen Fm
Type Locality and Naming
Jianghan Basin - SE. The naming section is located in the well in the northern part of Qianjiang County, Hubei. Named by the Jianghan Petroleum Administration (former May 7 oilfield) in 1965.
Lithology and Thickness
The lithology is marked by alternating grayish green and dark gray mudstone and siltstone, with minor marlstone, containing gypsiferous mudstone and oil shale, the top of which usually contains variegated mudstone. The maximum thickness may reach 1600 m.
Relationships and Distribution
Lower contact
It was deposited continuously with the underlying Qianjiang Fm.
Upper contact
It has an unconformable contact with the overlying Neogene Guanghuasi Fm [not in English Lexicon yet].
Regional extent
It is of restricted and scattered distribution and mainly found in the northern part of the Qianjiang area, Hubei.
GeoJSON
Fossils
Abundant fossils are contained in this formation. Ostracods are represented by the Cyprinotus jingheensis-Cyprois zhanggangensis assemblage, essentially consistent with the aspect of the continental Oligocene ostracod assemblage defined by Hou Youtang (1979). Charophytes are marked by the Maedlerisphaera chinensis-Charites molassica assemblage, which contains the Oligocene common elements Tectochara meriani etc. The sporopollen assemblage is Taxodiaceaepollenites-Quercoidites-Ulmipollenites-Ephedripites-Rutaceoipollis. In addition, the foraminifera Discorbis is also present.
Age
Depositional setting
This formation refers to a sequence of oil shale-bearing lacustrine-swampy deposits above the Paleogene Qianjiang Fm.
Additional Information