Abstract

A variety of carbonate and mixed carbonate-shale facies have been recognized in the Wuzhishan Formation (Famennian) of Guangxi, China. These facies include: (1) massive micritic limestone, (2) interbedded micritic limestone (1-15 cm beds) and shale (0.2-1.5 cm beds), (3) lenticular micritic limestone in a shale matrix, (4) nodular micritic limestone in a shale matrix, (5) limestone breccia with an argillaceous matrix, (6) styolitic micritic limestone. The massive micritic limestone facies represents a marine platform deposit with the three micritic limestone-shale facies representing deeper water deposits of outer platform origin. The lenticular and nodular fabrics are likely the products of compaction effects on interbedded limestone and shale. The limestone breccias were formed by dissolution collapse and by slope failure in outer platform and marine slope environments.

The lithologies are often arranged in shallowing upward cycles a few metres thick. In the north, where water depths were shallowest, massive micritic limestones dominate the cycles with lenticular limestones occurring in the basal portion of the cycles. Southward a variety of limestone shale facies occur in the lower portions of the cycles. In the most southerly localities limestone breccias are also present within the cycles.