Shangloucun Fm

No type section was assigned when the unit was erected. A section, the Lugou section, measured by Yang et al. (1991) was proposed by them as representative section of the formation by Ma (1998). The section is located in the Lugou Gully in Baoluo Township, about 3.5 km north of the junction of Lugou stream and Luohe River, or about 7 km north of the seat of Luonan County, Shangluo City, Shaanxi Province (110°46’02” E, 34°08’26” N). It is the middle portion of the same section shred with underlying Xialoucun Fm and overlying Wangyu Formation In this section, the Shangloucun Formation is 163.3 m thick. The Shangloucun Formation was named by Regional Geological Survey Team of Geological Bureau of Northwest China (1965). The name is derived from Shangloucun Village in Shimen Township, Luonan County, Shangluo City, southeastern Shaanxi Province.

Synonym: （上楼村组）; Shangluocun Fm (spelling); Ma (1998, p. 56) regarded the Shangloucun Formation as synonym of the Changhia Fm but this viewpoint is not followed here.

The Shangloucun Formation is basically a more or less metamorphic carbonate sequence. In the type area, lower part consists of dark grey and bluish grey, medium- to thick-bedded oolitic limestone, intercalated with phyllite. Upper part consists of grey and dark grey medium-bedded limestone, intercalated oolitic limestone. In the representative Luhou section, the formation is divided into 3 lithologic beds, from bottom up: 1, dark grey, megathick-bedded oolite-bearing calcite mylonite (19.5 m thick); 2, grey thick-bedded to massive calcite mylonite (27.9 m)；3, bluish grey thick-bedded to massive argillaceous stripe marble, intercalated lithic- and bioclast-bearing calcite marble with lithic dominated by oolxiaite (85.9 m). The limestone or oolitic limestone of Shangloucun Formation in the south half of Luonan County, south to Shimen Town, is different from the Changhia Fm in the area north to Shemin Town because it is more or less metamorphosed. In addition, in the type locality, the lower part of the Shangloucun Formation contains interbeds of phyllite, and at Lugou, southwestern Luonan, the formation is even more different in the domination of marble and mylonite.

The lower part of the formation in the type locality yields trilobite Fuchouia chiai and brachiopod Obolus sp. In the Lugou section, southwestern Luonan County, the upper part of the Bed3 yields trilobites Hejingaspis luoheensis, Inouyia sp., Liopeishania convexa, and Plebiellus lugouensis; trace fossils Arthrophycus sp., and Helicoichnus? sp., and unidentified algae.