Ta'erga Fm

Xinjiang

Jingeng Sha (coordinator) Group for the Regional Stratigraphic Chart of the Xinjiang Uygur Autonomous Region in 1981. The naming section is located in the Ta’erga area at the mouth of the Kuzgongsu River of Wucha County, Xinjiang. Uppermost formation in Ye'erqiang Gr (= Yarkant Gr).

Synonym: （塔儿尕组）; Targa Fm (spelling)

Lithology and Thickness:

It represents a set of variegated fine-clastic rocks, with the mudstone being predominant, intercalated with sandstone and marl, with a thickness of 500-1000 m.

Lithology-pattern: Sandy claystone

Relationships and Distribution:

Lower contact:

The Ta’erga Fm is conformable in contact to the underlying Yangye Fm, with a bed of conglomerate at the base.

Upper contact:

The Ta’erga Fm is conformable to the covering Kuzigongsu Fm, with a bed of red coarse clastic rocks at the base of the latter.

Regional extent:

The particular formation is distributed extensively in the foreland area of the South Tianshan Mts as in the areas of the river mouth of the Kuzgongsu River, Salt Farm-Kushwuliu Gully, Lesser Heiziwei; foreland area of the Kunlun Mts, including the regions of Yingjisha, Shace, Yecheng, Pishan, south of Hetian, as well as Duwa, Dusilapu-Aktala, Pulu and Shao’er Lake area. The lithology of the particular formation in various regions is less changeable, but with different thicknesses.

GeoJSON:

Fossils:

In the Kushwuliu Gully the lower part of the particular formation yields bivalves and gastropod fossils as represented by Pseudocardinia submargna, Bithynia manasensis, B. acuta, Viviparus fusistomas; Ostracod fossils such as Jingguella sinensis, Limnicythere ventricosa and Metacypris macherrowi. At the mouth of the Kangsu River it yields such Ostracod fossils as Darwinula magna, D. impudica, D. sarythirmenensis, Uiguria xinjiangensis, as well as Chareae fossils.

Age:

Schematic strat column suggests Bajocian age.

Age span:

Beginning stage: Bajocian

Fraction up in beginning stage: 0.0

Beginning date (Ma):

Ending stage: Bajocian

Fraction up in ending stage: 1.0

Ending date (Ma):

Depositional setting:

It is interpreted as a fluvial-lacustrine environment.

Depositional-pattern:

Additional Information

Compiler

Jingeng Sha (coordinator)