Digital characterization of thrombolite-stromatolite reef distribution in a carbonate ramp system (terminal Proterozoic,Nama Group,Namibia)

摘要

The stratigraphic architecture of a terminal Proterozoic carbonate ramp system (ca.550 Ma,Nama Group,Namibia) was mapped quantitatively with digital surveying technologies.The carbonate ramp consists of a shoaling-upward ramp sequence in which thrombolite-stromatolite reefs developed at several stratigraphic levels.The reefs are associated with grainstone and heterolithic facies and exhibit diverse geometries and dimensions related to the position in the sequence-stratigraphic framework.