Abstract:

 Stromatolitic carbonate succession is common in the Precambrian. In the Yanshan Area, the third member of the Mesoproterozoic Gaoyuzhuang Formation is made up of a particular limestone succession with the sparseness of stromatolites, and this limestone succession has been defined as the nonstromatolitic carbonate succession. For the nonstromatolitic carbonate succession, the third member of the Gaoyuzhuang Formation at the Qiangou section in Beijing is a typical example, in which three thirdorder sequences can be discerned according to the cyclicity reflected by successions of sedimentary facies. Within these thirdorder sequences, there are many subtidal carbonate cycles that are made up of both the mediumto thinbedded aphanitic micrites and the thinbedded marls in the transgressive and the early highstand system tracts, and many grotesque sedimentary structures are developed in the bedding planes of aphanitic micrites. These sedimentary structures, including the domal structure, the irregular reticular and the irregular chaotic tepee ridges, and the palimpsest ripple, make up an association of the microbial induced sedimentary structure (MISS). Therefore, both the special MISSs and the particular lithological types make the third member of the Mesoproterozoic Gaoyuzhuang Formation at the Qiangou section become the representative of the Precambrian nonstromatolitic carbonate succession. More importantly, this succession was formed during the stromatolitic golden age, which provides useful information for the further understanding of the evolving carbonate world of the Precambrian.

Key words: Key words: MISS; the nonstromatolitic carbonate succession; Gaoyuzhuang Formation; Mesoproterozoic; Qiangou Section in Yanqing