Daqingshan Fm
Type Locality and Naming
It was named by Sun Jiancu in 1934. The naming locality is situated at Daqing Mts, Inner Mongolia, with its reference section being located in the area of Xigoumen-Heiniugou, Right Banner of Tumote, Inner Mongolia.
Synonym: （大青山组）
Lithology and Thickness
Composed of thickly stratified purple and grey-green continental coarse-grained clastic rocks. Lithologically the formation is divisible into two members: Lower member is alternating layers of purple conglomerate and sandstone, consisting of pebble-bearing sandstone, light-grey thick-bedded crystal limestone, grey-violet and purple sandstone and siltstone, intercalated with thin-bedded limestone, grey-green sandstone and siltstone, yielding fossil plants and insects of Coleoptera species, with a thickness of over 2445 m. Upper member consists of violet and violet-grey thick-bedded sandstone intercalated with conglomerate, grey-green conglomerate intercalated with sandstone, siltstone and grey, yellow-green sandstone and sandy conglomerate intercalated with fine-grained sandstone, carbonaceous shale and coal seams. The thickness of this member is of 2464 m. Its total thickness is 911-4757 m.
Relationships and Distribution
Lower contact
There is a fault contact between the above-mentioned two members. It is covered unconformably by Cretaceous strata of the Lisangou Fm, or the Bainuyangpan Fm.
Upper contact
There is a fault contact between the above-mentioned two members. The formation overlies unconformably the Archean gneiss, Shiguezi Gr, or Changhangou Fm
Regional extent
The formation is distributed extensively in the area of the Daqing Mts, including, for instance, the Dagou Gully-Xiaowanjiaogou Gully to the east of the Tumote Left Banner, Shigue District, Baotou City; the Ximengou Gully-Heiniugou Gully of the Tumote Right Banner; and the area to the north of Huhehote City and Zuozi County. Both the lithology and thickness of the formation tend to vary greatly, the grains of the rocks are getting coarser towards west and north, with the limestone being reduced, or Compiler
Jingeng Sha (coordinator) lacking; and with the thickness getting smaller easterly, being of over 4757 m in the Heiniugou Gully area, of over 3110 m in the Xiaowanjiagou Gully area, and of 911 m still easterly till the Dianhongdai area.
GeoJSON
Fossils
The upper part yields plant fossils Elatocladus submanchurica, Podozamites lanceolatus, Nilssonia sp.; the spore-pollen fossils with the pteridophyta pollens among them making up 48.8% and being represented by Leptolepidite sp., Cingulatisporites cf. Compiler
Jingeng Sha (coordinator), Psilosisporites trichopapillosus, while the gymnosperm pollens constituting 51.2%, and being represented by Ginkgo sp., Pagiophyllum, Cycas sp.; bivalves fossils as represented by Ferganoconcha subcentralis, F. sp., as well as Ostracod fossils as represented by Mongolianella ximengensis.
Age
Depositional setting
This formation represents deposits of fluvial facies.
Additional Information
Beginning date (Ma):
Ending stage: Oxfordian
Fraction up in ending stage: 0.5
Ending date (Ma):
Depositional setting:
This formation represents deposits of fluvial facies.
Depositional-pattern:
Additional Information
Compiler
Jingeng Sha (coordinator)