Akekule Fm
Type Locality and Naming
Dong Yanru named it in 1990. The type section is Yuecan Well 1 at 83°04′E and 40°51′N in the northeastern Tarim Basin. A reference section is Sha Well 10 near Langa. Middle formation in Manjiar Gr.
Synonym:
Lithology and Thickness
It is mainly composed a set of dark gray mudstone interbedded with gray or grayish sandstone and gravelly sandstone. It is divided into two members. Lower member consists of the lower part of variegated massive conglomerate and dark gray siltstone, the middle part of dark gray and purplish brown mudstone intercalated with siltstone, and the upper part of grayish gravelly sandstone and fine sandstone intercalated with thin beds of dark gray mudstone and carbonaceous mudstone, 131 m thick. Upper member consists of dark gray and grayish black mudstone intercalated with grey siltstone and fine sandstone, and with greyish black carbonaceous shale and thin coal beds at the top of the member, 155 m thick.
Relationships and Distribution
Lower contact
This formation is in conformity on the underlying Ketuer Fm (Ketur Fm) by variegated massive sandstone and conglomerate.
Upper contact
It is in conformity under the overlying Halahatang Fm by carbonaceous mudstone intercalated with thin coal beds.
Regional extent
The formation is widespread in the Tarim Basin, and it is observed in many boreholes from the west to Sha Well 10 and the south to Acan Well 1 till the north to Minfeng-Qiemo. The thickness varies from 125 m to 500 m.
GeoJSON
Fossils
Microspore Punctatisporites-Caytonipollenites-Aratrisporites Assemblage.
Age
Depositional setting
It is interpreted as the sediments in shallow lake, delta and beach bar facies. It is an important oil and gas reservoir.
Additional Information