Abstract:

The Neoproterozoic Shiwangzhuang Formation in the southern part of Shandong Province is marked by a set of dolomitic deposits, in which several beds of edgewise calcirudites and scouring surfaces represented by underside structures such as the wave-shaped, the irregular-shaped, the V-shaped and the U-shaped trough molds are developed. All of these features indicate that the edgewise calcirudites may represent the typical tempestite, which is formed in the shallow ramp affected frequently by strong storm. Therefore, the tempestite in the Neoproterozoic Shiwangzhuang Formation provides a useful actual evidence to study the paleogeographical setting of the Neoproterozoic in the southern part of Shandong Province. Since the tempestite represented by edgewise calcirudites is widespread in carbonates of the Precambrian especially for those subtidal deposits of shallow ramp, the detail description for this type of deposits and their genetically relative sedimentary structures is helpful to reconstruct the sedimentary environment of the Precambrian.

Key words: storm deposit, carbonate rock, graded bedding, Neoproterozoic, South Shandong