上扬子地台南缘早志留世埃隆期碳酸盐岩岩石学特征及沉积环境

发布时间：2018-06-25 03:57

本文选题：埃隆期 + 碳酸盐岩　；参考：《岩石学报》2017年04期

【摘要】：上扬子地台南缘早志留世埃隆期发育的碳酸盐岩,近期揭示具有较好的油气勘探前景,但有关该套岩层的岩石学特征及其沉积环境研究需要进一步深入。论文以野外地质剖面和室内薄片鉴定为基础,对上扬子地台南缘早志留世埃隆期碳酸盐岩开展系统的岩石颗粒组分、岩石类型和沉积环境分析。发现早志留世埃隆期碳酸盐岩颗粒类型主要为生物碎屑,含少量内碎屑与鲕粒;根据曾允孚先生等的碳酸盐岩结构成因分类方案,该地区碳酸盐岩主要有7种类型:包括亮晶鲕粒灰岩、亮晶生物屑灰岩、珊瑚礁灰岩、亮晶砂屑灰岩、砂屑-生物屑微晶灰岩、微晶砂屑灰岩和微晶灰岩。根据岩石学特征和野外露头分析,认为在早志留世埃隆期研究区从早期到晚期沉积环境经历了碳酸盐缓坡到碳酸盐台地的转变,并发育了外缓坡、内缓坡、台地边缘斜坡、台地边缘滩、台地边缘生物礁、开阔台地等亚相。以三级层序为编图单元,揭示了礁滩沉积区域展布特征,生物礁滩体主要发育于SQ2层序,具有环带状展布的特征。
[Abstract]:Carbonate rocks developed in the early Silurian Elon period on the southern margin of the upper Yangtze platform have a good prospect for oil and gas exploration in the near future, but the petrological characteristics and sedimentary environment of this set of rocks need to be further studied. On the basis of field geological profile and laboratory sheet identification, this paper analyzes systematically the rock grain composition, rock types and sedimentary environment of early Silurian Eelon carbonate rocks in the southern margin of the upper Yangtze platform. It is found that the grain types of early Silurian Eyronian carbonate rocks are mainly bioclastic, containing a small amount of internal detritus and oolitic particles, according to the genetic classification scheme of carbonate rock structure of Mr. Zeng Yunfu, etc. There are mainly seven types of carbonate rocks in this area: bright grained oolitic limestone, sparkling bioclastic limestone, coral reef limestone, sparkling sandclastic limestone, sand-bioclastic microcrystalline limestone, microcrystalline sandclastic limestone and microcrystalline limestone. According to the petrological characteristics and field outcrop analysis, it is considered that the sedimentary environment of the early Silurian Eelon period experienced a transition from the early to the late stage of the sedimentary environment to carbonate platform, and developed the outer gentle slope, the inner gentle slope and the marginal slope of the platform. Platform edge beach, platform edge reef, open platform and other subfacies. Taking the tertiary sequence as the mapping unit, the distribution characteristics of the reef beach sedimentary region are revealed. The reef beach body is mainly developed in SQ2 sequence and has the characteristics of circular zonal distribution.
【作者单位】：成都理工大学沉积地质研究院;油气藏地质及开发工程国家重点实验室(成都理工大学);
【基金】：中国地质调查局项目(1212011220758) 成都理工大学中青年骨干教师培养计划(JXGG201537、JXGG201538)联合资助
【分类号】：P618.13

【相似文献】