Kekemaideng Fm
Type Locality and Naming
Junggar Basin NW. The naming section is the same as the Halamagai Fm. Geographical coordinates: 46°33′48.48″N—87°47′10.38″E(GPS). Named by No. 631 Geological Party of the former Ministry of Geology and Zhu Xia et al. in 1955, originally as a member of the Halamagai Fm.
Lithology and Thickness
Yellowish massive fine to coarse gravels intercalated with thin to thick-bedded mudstones and sandstones. 17.1 m in thickness at the type locality, and ~5 m at the Tieersihabahe section.
Relationships and Distribution
Lower contact
Unconformably overlies the Dingshanyanchi Fm (see Additional Information for discussion).
Upper contact
Conformably underlies the Halamagai Fm.
Regional extent
Fuhai, Fuyun Counties, at the Duolebulejin and Tieersihabahe Terrance.
GeoJSON
Fossils
Artiodactyla: Palaeomerycidae indet, Dicrocerus, Turcocerus, Kubanochoerus sp.; Proboscidea: Gomphotherium tassyi, Platybelodon grangeri, Choerolophodon sp., Carnivora: Hoplictis cf. helbingi
Age
Depositional setting
Primarily channel facies.
Additional Information
Upper contact:
Conformably underlies the Halamagai Fm.
Regional extent:
Fuhai, Fuyun Counties, at the Duolebulejin and Tieersihabahe Terrance.
GeoJSON:
Fossils:
Artiodactyla: Palaeomerycidae indet, Dicrocerus, Turcocerus, Kubanochoerus sp.; Proboscidea: Gomphotherium tassyi, Platybelodon grangeri, Choerolophodon sp., Carnivora: Hoplictis cf. helbingi
Age:
Deng et al. (2019; China Integrated Strat) indicate the basal Dingshanyanchi Fm is ca. 60% up Serravallian (and continues to end-Messinian) with the underlying Kekemaideng Fm beginning in lowermost Selandian (ca. 15% up)
Age Span:
Beginning stage: Serravallian
Fraction up in beginning stage: 0.15
Beginning date (Ma):
Ending stage: Serravallian
Fraction up in ending stage: 0.6
Ending date (Ma):
Depositional setting:
Primarily channel facies.
Depositional-pattern:
Additional information
The presence of the Kekemaideng Fm at the Dingshanyanchi section is debated. Meng et al. (2008) considered that the Kekemaideng Formation is contemporary with the lower part of the Dingshanyanchi Fn with different facies. However, although it is hard to be direct compare, the Kekemaideng fossil assemblage sames to be slightly earlier than that of the bottom Dingshanyanchi Fm. At the Dingshanyanchi section, there are ~5 m thick yellowish sandstones between the Halamagai Fm and Dingshanyanchi Fm, which might be correlated to the Kekemaideng Fm.