Heyao Fm
Type Locality and Naming
Central Henan-Hubei border region. The Heyao Fm was named by Ma Xingyuan et al., in 1975. The typical section is situated in Heyao village of Foguangyu area in Yanshi County, Henan Province.
Synonym: （何窑组）; Hejiayao Fm.
Lithology and Thickness
Lower part (from upper to lower) is greenish yellow shale intercalated with thin-bedded quartzose sandstone, grayish purple manganiferous dolomite, sandy dolomitic limestone. From upper to lower, the Middle part is composed of gray limestone, pelitic dolomite, greenish yellow shale and carbonaceous shale, stromatolite-bearing limestone, dolomite and pelitic limestone intercalated with shale. Upper part is composed of green shale, siltstone intercalated with pelitic limestone and mudstone. The thickness is about 337 m.
[Figure: Limestone with molar tooth structures in Foguangyu, Songshan area, Henan Province]
Relationships and Distribution
Lower contact
The basal part of the Heyao Fm, composed of light gray, greenish gray thin to medium-bedded dolomitic limestone, rests conformably on the underlying Luotuopan Fm
Upper contact
The upper part is in faulted contact with a bed of dark gray marlite to the overlying Hongling Fm
Regional extent
Central Henan-Hubei border region. The Heyao Fm is mainly distributed in north slope of the Yuzhai- Songshan Mountains, west from the Foguangyu of Yanshi County, eastward to Shaolinsi area (Dengfeng County), then to Wuzhiling region in the juncture of Dengfeng, Mixian and Gongyi counties.
GeoJSON
Fossils
It yields stromatolites: Anabaria f., Inzeria f., Gymnosolen f.; and abundant microplants: Trachysphaeridium simplex, T. incrassatum, T. minor, Taeniatum crassum, Laminarites aff. antiquissimus.
Age
Depositional setting
Additional Information