Hannuoba Fm
Type Locality and Naming
The type section is located at the “Hannuoba section” near Hannuoba village (E114°48′, N40°57′), Youlougou town, Zhangbei County, Hebei Province. The name is derived from the “Hannuoba (Han Jo Pa) Basalts” used by Barbour (1929). Pei et al. (1963) firstly used the name “Hannuoba Fm”. It was formally and validly published by BGMRH(Hebei)P (1989).
Synonym: Han Jo Pa Fm. According to Gao et al. (2014a), all the Weichang Basalt Fm, Yuxian Basalt Fm, Qipanshan Basalt Fm, Wuliangtai Basalt Fm, Tianzhen Basalt Fm, and Yuxian Fm are synonyms of the Hannuoba Fm.
Lithology and Thickness
The Hannuoba Fm is mainly characterized by a series of basalts. Lower part consists of greyish-black and greyish-green fine to coarse olivine basalts. Upper part is formed by blackish-green, yellowish-green, greyish-green, and greyish-white dense olivine basalts, and its bottom often contains conglomerates interbedded with multilayers grey or red sandy clays, clays or laminations of lignite. Its depositional interlayers produce mammalian and plant fossils. Its thickness is in range of 1 to 458 m.
Relationships and Distribution
Lower contact
In the type section, the Hannuoba Fm unconformably contacts with the underlying lower Cretaceous Nantianmen Fm.
Upper contact
In the type section, the Hannuoba Fm unconformably overlain by Pleistocene deposits.
Regional extent
The formation is distributed to Bashang area (Zhangbei, Weichang, Wuluogongshan, Shangyi, Yangyuan-Yuxian), Hebei Province.
GeoJSON
Fossils
Mammals: Monosaulax changpeiensis, Lagomorpha gen. et sp. indet. (Li, 1962). Plants: Comptonia anderssonii, Pinus sp., Carpinus sp. (BGMRH(Hebei)P, 1989)
Age
Depositional setting
It is interpreted as a volcanic eruption with short period lake environment.
Additional Information