Fig. 4

a, b The nodular, platy limestone analyzed occurs between oolitic packstones and grainstones of the 1st and the 2nd cycle in the Zhangxia Formation (thickness of cycle 2 is about 12 m). b The zones Z1–Z5 were analyzed for different facies types occurring in single limestone beds. c In zone Z3 the depicted representative section contains all characteristic sedimentary features. Note the common pinch-out (black arrows) of beds within a lateral distance of some centimetres to decimetres, which results in the characteristic wavy texture of the platy limestone. Furthermore, cross-cutting features occur (white arrows) with symmetric and asymmetric boundaries. Parallel boundaries of single beds occur rarely (modified from Meng et al. 1997)