燕辽地区蓟县系隐藻叠层石碳酸盐岩沉积环境及沉积模式

SEDIMENTARY ENVIRONMENT AND SEDIMENTATION MODELS OF THE STROMATOLITIC CARBONATE ROCKS IN JIXIAN SYSTEM, CHINA

燕辽地区蓟县系地层主要属于次稳定型内源建造类的藻礁碳酸盐建造[1]。它以发育隐藻(礁)碳酸盐岩(叠层石)为主要特征。这类碳酸盐岩不仅是沉积学研究的一项重要课题,而且在研究建造性质、成因环境以及经济地质学方面,均有重要意义。现已发现油气、Pb、Cu、Zn、Mn、Fe、S及磷块岩矿床等及隐藻碳酸盐岩(叠层石)有直接关系。如:长城系叠层赤铁岩、高于庄组的叠层硫铁岩、陡山坨组的叠层磷块岩、东川落雪组叠层铜矿密两两比系的叠层铅锌矿、卡拉套下寒武统的叠层锰矿等。显然研究叠层石成因环境对揭示这些矿床成因和控矿条件是十分重要的。

The kinetics of crypto-algal stromatolitic carbonate rock can be interpreted on the basis of current power (C), degree of freedom (G), and strengh of gas escape (E), as proposed by Oluthers. Based on the index C, E, G, stromatolitic rock can be devided into different microfacies.Through comprehensive investigation, a general sedimentation model of the stromatolitic sequence of Jixian system is worked out. Comparing it with the model for Rocknest Formation in Canada, we found that these two are conspicuously similar.