Abstract: | The Cambrian and Ordovician on the northern Tarim Platform are mainly composed of carbonates. On the basis of detailed outcrop
analysis, the sequence stratigraphic system of the Cambrian-Ordovician in the northern Tarim Platform is outlined in this
paper. Altogether 35 third-order sequences, 12 supersequences, 4 supersequence sets and 2 megasequences are recognized. The
characteristics of the major sequence boundaries have been documented with an integrated examination of outcrop, seismic and
borehole data, and the ages of these sequence boundaries have been calibrated through the combination of sequence stratigraphy
with biostrati-graphy. It is discovered that there is good correlation of the sequence stratigraphy of the Cambrian-Ordovician
among Tarim, Yangtze and North China platforms. This may illustrate that the development of the Cambrian-Ordovician carbonate
sequences in these three platforms is mainly controlled by regional or global sea level changes. This forms the theoretical
basis for the construction of high-resolution chronostratigraphic system of the Cambrian-Ordovician in the three platforms
in China. |