四川盆地二叠系长兴组生物礁发育的差异性及控制因素

为厘定四川盆地不同区带露头剖面或钻井剖面长兴组生物礁发育的差异性，通过野外露头剖面详细观测、钻井岩心详细观察及室内综合研究，对四川盆地二叠系长兴组生物礁发育特征进行了系统研究和总结。研究揭示四川盆地不同区带长兴组生物礁差异性表现为：发育期次不同，包括不发育生物礁到发育4期生物礁；生物礁旋回发育的完整程度不同，包括同一地点不同期次旋回的差异和不同地区同一期次礁旋回的差异；生物礁旋回的岩性、生物组合的不同；生物礁空间展布特征不同，包括多排成带发育、分布模式、单排发育模式和环状分布模式。在此基础上，提出了控制生物礁发育的4个因素，即古地貌决定了礁发育的位置及形态，古环境控制生物礁发育期次及礁体完整性，古水深（海平面变化）控制生物礁物质组合及旋回性，古生物控制生物礁的物质组成及礁体的完整性。

Differences and controlling factors of Changxing Formation reefs of the Permian in the Sichuan Basin

The development characteristics of the reefs in the Permian Changxing Formation in the Sichuan Basin are systematically studied to determine the differences of the reefs developed in the same formation of different plays through observation of outcrops and cores as well as experiments.The results show that the reefs from different plays vary in the development stage from nil to as much as four stages of development; in the completeness of reef cycles, including the differences in cycles of the same location but of different stages or the same cycle but of different locations; in lithofacies and biological assemblages; and in reef spatial distribution, including a banded distribution of multiple rows, dispersed distribution, single-row distribution and ring distribution.Based on the results, we proposed four factors controlling the reef development, i.e., the palaeogeomorphology determines the location and morphology; the palaeoenvironment controls the development stages and the integrity; the palaeobathymetry (sea-level changes) controls the reef assemblages and cyclicity; and the palaeontology controls the reef composition and integrity.