Hongliuhe Fm
Type Locality and Naming
The type section is located in the Hongliuhe River valley of Shaquanzi, Hami County, Xinjiang. It was named by the 1st Regional Geological Survey Expedition under the Xinjiang Geological Bureau in 1958-1960.
Lithology and Thickness
Mixed facies of Limestone, Clastics and Volcanics. It is divisible into three subformations as follows: T he base of the Lower subformation is a brown conglomerate with a thickness of 100 m; the middle part of the lower subformation consists of grey limestone, crystalline limestone and grey-green sandy limestone, with a thickness of 300-400 m; and the upper part of the lower subformation is composed of grey-yellow pebble-bearing sandstone, conglomerate, yellowish-brown calcareous feldspar fine-grained sandstone, with a thickness of 450 m. The Middle subformation is composed mainly of grey-green, dark-grey and purple diabasic porphyrite, diabase and basalt, intercalated with tuffaceous sandstone and tuffaceous siltstone, with a thickness of over 1000 m. The lower and middle parts of the Upper subformation are interbeds of grey-yellow and grey-green thin-bedded and medium-grained sandstone, metamorphosed medium-grained feldspar-rich sandstone and conglomerate; and the upper part of the upper subformation is composed of metamorphosed calcareous medium-grained feldspar-rich sandstone, intercalated with ferruginous and siliceous oolitic limestone lenses, with a thickness of 1000 m. The various subformations are in conformable contacts with one another.
Relationships and Distribution
Lower contact
Unconformably overlaps the strata of various ages from the Sinian System to the Upper Carboniferous Series
Upper contact
Conformable contact with the overlying Luotuogou Fm in the Hongliuhe River Valley, but at all other localities the exposures of the formation are not complete. Lexicon chart indicates next higher unit is the Aqikebulake Fm in Hami region.
Regional extent
The formation has a complete exposure in the Hongliuhe River Valley and Cihai-Luotuogou region. In the Cihai area the Lower subformation represents a suite of tuffaceous conglomerates, with a thickness of 135 m; westerly up to the Matishan and Xiaoqingshan alignment, it represents a rhythmite composed of conglomerate, sandstone and siltstone, intercalated with limestone and slate, with a thickness of 1150 m. The Middle subformation in the Cihai area is composed of basalt, andesite, dacite and tuff, with the basalt of them being possessed of pillow structure, with a thickness of over 982 m; westerly up to the Luotuogou area its thickness being of 907 m. In the Baishan area at the boundary between Gansu and Xinjiang the Middle subformation is composed mainly of tuff and tuffaceous sandstone, and secondly of basalt, tholeiite, olivine basaltic porphyrite, diabasic porphyrite and andesitic porphyrite, with a thickness of 2278 m. And the Upper subformation in the Cihai area is characterized by its comprising feldspathic greywacke, clayey siltstone, pebble-bearing sandstone and micro-conglomerate, with its top part being composed of tens of meters of basic to intermediate-acidic volcanic rocks, and with a thickness of over 1198 m for this subformation.
GeoJSON
Fossils
The Lower subformation yields Brachiopods such as Stenoscisma cf. mutabilis, Spiriferella saranae, S. heilhaviformis, S. grandis, Rhynchopora sp., Waagenoconcha sp., Muirwoodia cf. mammata, M. cf. mammatiformis, and a small amount of Plant fossils (phytolites) such as Cordaites schenkii. In the Cihai region, the Middle subformation yields brachiopods represented by Neospirifer sp., Punctospirifer sp., Schellwienella sp., Cancarinella sp., and bivalves as represented by Modiolus and Liguallise. In the Hongliuhe River Valley the Upper subformation yields Bivalves represented by Myalina (Myalinella?) sp., Edmondia sp., Nucula sp., and Nuculopsis sp.,
Age
Depositional setting
It is interpreted as marine volcanics and island arc marginal marine deposits.
Additional Information