Types Of Barrier Carbonate Platform And Their Evolution

Based on carbonate research results in Sichuan Basin, Tarim Basin, Ordos Basin and many literatures at home and abroad, the paper innovatively put forward a kind of genetic classification in carbonate platform which included three factors(barrier conditions, paleogeographic conditions and gradient).In this paper, platform was divided into two broad categories and eight sub-types, they are Barrier platform with gentle slope, Barrier platform with steep slope, Barrier isolation platform with gentle slope, Barrier isolation platform with steep slope, No barrier platform with gentle slope, No barrier platform with steep slope, No barrier isolation platform with gentle slope, No barrier isolation platform with steep slope. We summarized the basic characteristics of each kind of platform and established corresponding depositional mode, reservoir development and distribution pattern.We believe that evolution of carbonate platform just like the evolution of the universe, they Usually have three stages(formation, heyday and perish).these three stages are in accordance with tectonic stretch and subsidence, tectonic stable period and tectonic uplift period. There are two kinds of evolutionary trends:One is from No barrier platform evolved into Barrier platform, finally stopped due to uplift the exposure; The other is from No barrier platform evolved into Barrier platform, then platform was submerged because of rapid subsidence. The paper took Steep slope barrier platform with humid climate of Changxing Formation, Steep slope barrier platform with arid climate of Feixianguan Formation, Steep slope barrier platform with arid climate of Jialingjiang Formation and Leikoupo Formation in Sichuan basin as examples to detailedly dissected lithofacies paleographic characteristics and reservoir distribution rules of these three kinds of barrier platforms. The paper also pointed out advantageous exploration direction of three kinds of barrier platforms. Anyway the paper has innovation in Basic theory, actual application effect, academic and practical value.