Malanbian Fm

The type section is located at the Malanbian Reservoir, Tianxin Township, Xinshao County, Hunan. It was named by Tan Zhengxiu and Tang Xiaoshan in 1983.

Limestone. Composed mainly of littoral-neritic carbonate rocks in the central Hunan area, and divided into three parts. Lower part consists of thick- and very thick-bedded limestone and dolomitic-banded limestone, ~50 m thick. Middle part is of gray-black thin-bedded bioclastic micritic limestone intercalated with shale or marl, containing abundant brachiopods, corals, platform conodonts, etc., 10−20 m thick. Upper part is of thick-bedded and very thick-bedded limestone, ~30 m thick. In the southern Hunan area, the thickness increases to 200−300 m, in which the lower part consists of thick-bedded bioclastic limestone, with minor shale at bottom; the upper part is of thick- and very thick-bedded dolomitic banded limestone and bioclastic limestone, locally with lumps of siliceous rock.

In the central Hunan area, it contains the Coral Pseudouralinia tangpakouensis zone, the brachiopod Eochoristites-Martiniella zone, the Conodont Siphonodella levis zone, and the foraminifera Chernyshinella zone, belonging to the Tournaisian Age. In southern Hunan, the upper part contains the same fossils as in central Hunan, Early Carboniferous in age; the lower part contains the coral Cystophrentis extensional zone, the Foraminifer Quasiendothyra communis-Qikobeitusana zone, and the Brachiopod Cyrtospirifer-Yanguania-Paulonia zone, basically consistent with those contained in the upper Menggong’ao Fm in central Hunan, Late Devonian Famennian in age.

It is interpreted as littoral-neritic carbonates.