Baoban Gr

Western Hainan. The Baoban Gr was named by the Party of Regional Geological Survey, Guandong Bureau of Geology in 1962 and published by Zhao Hong in 1964. The representative section is the Changhua River section in Changjiang County, Hainan Province. Subdivided into the Gezhencun Fm and Ewenling Fm.

Synonym: （抱板群）

The Baoban Gr is subdivided into the Gezhencun Fm and Ewenling Fm in ascending order, with a conformable contact between them. The Baoban Gr is 2381 m thick.

The upper formation, the Ewenling Fm, is subdivided into upper and lower members. Lower member is composed of quartzite two-mica schist, and two-mica quartz schist, with a feldspar quartzite in the base and a thickness that varies from 420 m to 880 m. The lower part of the Upper member is dominated by quartzite, commonly with graphite. The upper part of upper member is composed of plagioclase-mica-quartz schist, two-mica quartz schist sandwiched with feldspar-quartzite and graphite schist (graphite beds). The thickness of the upper member varies from 340 m to 550 m.

The lower formation, the Gezhencun Fm, is dominated by gneiss, mainly plagioclase gneiss with minor biotite-plagioclase leptite and hypersthene granulite, having experienced severe migmatization.