上扬子西北缘震旦系灯影组碳酸盐岩显微图像数据集

A microscopic image dataset of Sinian carbonate from Dengying Formation on the northwestern margin of Upper Yangtze

本文报道的上扬子西北缘震旦系灯影组为南华纪冰期结束以后在上扬子地区沉积的首套大规模碳酸盐岩地层。其不仅记录了震旦纪对全球气候回暖的响应,而且还记录了早寒武世骨骼动物大爆发前夕的海洋微生物的演化与碳酸盐岩生长的信息,同时这些微生物生长形成的丘滩体白云岩正成为目前四川盆地深层古老碳酸盐岩油气勘探的目标。因此,采集自扬子地台西北缘绵竹清平及镇巴鹿池剖面的119个岩石薄片的显微图像,其揭示的岩石的组分、结构特征随时间变化,在剖面上总体表现为硅质岩、泥微晶白云岩、藻纹层云岩及颗粒白云岩的序列,反映了扬子台地西北边缘陆缘海背景下,在一个缓慢海平面上升过程中,受次级海平面波动影响的碳酸盐岩台地边缘的生长发育过程。数据集详细记录了样品的采集位置、大致的地层时代、岩石组分和结构特征等信息,可应用于扬子地台西北缘震旦纪灯影组的岩石微相研究,也可应用于图像智能识别等交叉学科研究中,同时可为油气储层描述和成因机理分析、教学科普等社会生产实践活动提供基础资料服务。

The paper presents a datdaset of marine carbonate rocks from the Sinian Dengying Formation on the northwestern margin of the Yangtze,which is the first large-scale carbonate formation deposited in the Upper Yangtze region after the Nanhua Ice Age.It records not only the Sinian response to global warming,but also information on the evolution of marine microorganisms and the growth of carbonate rocks on the eve of the Early Cambrian skeletal animal outbreak.Moreover,mound-shoal dolomite has currently become an important indicator of deep-seated ancient carbonate oil and gas in Sichuan Basin.Microscopic images of the 119 rock thin sections collected from Qingping,Mianzhu,Luchi,and Zhenba sections in the northwestern margin of the Yangtze Platform revealed that the composition and structural characteristics of the rocks change with time,and the sections generally manifest to have the sequence of siliceous rock,micrite dolomite,algae dolomite and granular dolomite,reflecting the development process of the edge of the carbonatite platform margin affected by secondary sea level fluctuations during a slow sea level rise against the epeiric sea on the northwestern margin of the Yangtze Platform.The dataset records in detail such information as the location,approximate stratigraphic age,rock composition and structural characteristics of the samples.It can be applied to the study of rock microfacies of the Sinian Dengying Formation on the northwestern margin of the Yangtze Platform,and to the interdisciplinary research concerning,for example,intelligent image recognition.It also provides basic information services for production activities such as oil and gas reservoir description and formation mechanism analysis,teaching and science popularization.