Anyuan Fm

It was named by Zhou Zuogong and Lei Xuan in 1931, and first quoted by Huang Jiqing and Xu Keqin in 1936-1937. The named section is located in Anyuan, Pingxiang City, Jiangxi Province.

Synonym:

It is divided into four lithologic members from bottom to top.

The Zijiachong Mbr is mainly composed of conglomerate, sandstone, siltstone, mudstone, and coal seam interbedded with carbonaceous mudstone. This section is widely distributed, and its thickness varies greatly. The thickness is 139 m in Anyuan, 100 m in Xinyu County, 315 m in Yongshan, 412 m in Luoshi, and 659 m in Chongren County. The general thickness is about 300 m.

The current Sanjiachong Mbr in Pingxiang is dominated by marine mudstone interlaced with dolomite lens or nodules. It is 163 m thick. The distribution of this member is the same as that of the Zijiachong Mbr. From Pingxiang east to the flower drum mountain in Xinyu, the Marine facies layer is obvious. The Leping area is interbedded with thin coal seam with a thickness of only 36 m and Chongren Lipi with a thickness of 95 m.

The named place of Sanqiutian Mbr is not complete, which is represented by Siliting section in Wanzai County. The lithology is quartz sandstone, siltstone and mudstone with unstable coal seam, but generally the sedimentary clasts are coarser and the conglomerate is more developed, and the bottom is grayish white and grayish purple gravel sandstone. The thickness of this section varies greatly. The Anyuan area has no upper-limit, and the visible thickness is 397 m, Tangpu in Yifeng County is 775 m, Lushan Mountain is 520 m, Yanshanwulinshan is the thinnest (0~20 m), and Lipi is the thickest (984 m). The lithology of Sanqiutian member of Anyuan section is composed of gray and brown siltstone, fine sandstone, quartz sandstone and conglomerate, interspersed with carbonaceous mudstone and coal seam. The Tianhe strata are 202 m thick, Badu 545 m thick, and Zhoufang more than 252 m thick.

Jiangxi District Diversion Team established the Duojiang Mbr in 1977. The naming place is located in Duojiang, Wanzai County. This member used to belong to the section of Sanqiu Field. The lithology is dominated by gray white medium to thick coarse-grained quartz sandstone interbedded with fine sandstone. The upper part is developed with gray black thin siltstone and silty mudstone, and the bottom is composed of huge thick layer of quartz conglomerate. The thickness is generally 140 to 360 m.

Anthrophyopsis crassinervis, Ptilozamites chinensis, Baiera minuta, Ctenopteris sp., Pterophyllum ptilum, and so on were produced in Zijiachong Member.

Marine bivalves Bakevelloides cf. hekiensis, Codostylina sp.; plants Dictyophyllum nathorsti, Equisetites sp. were produced in Sanjiachong Member.

Bakevelloides cf. hekiensis, B. matsushitai, Jiangxiella subovata, J. cf. elliptica, J. datianensis, J. orbicularis, Gervillia sp., Modiola problematica, Permophorus emeiensis, Myophoriopis sp., Unionites sp., Anomozamites major, Pterophyllum sp. and so on were produced in Sanqiutian Member.

Bivalve producing Myophoriopis sp., Jiangxiella sp., Lilingella robusta, Unionites? sp., Hunanella sp., H. ovata, H. oblongiformis; Plants Neocalamites hoerensis, Czekanowskia sp., Phoenicopsis sp., and others were produced in Duojiang Member.

The Zijiachong Mbr is mainly composed of continental and marine facies.

The Sanjiachong Mbr is a marine coal - bearing structure.

The Sanqiutian Mbr is dominated by land facies.