塔里木盆地志留系震积岩特征及其意义

在区域构造背景研究和岩心观察的基础上,在塔里木盆地志留纪地层中识别出震积岩。震积岩的主要标志是发育各种类型的软沉积变形构造,包括微阶梯状正断层、层内小褶皱、扭曲变形、振动液化砂岩脉、震塌岩等。通过对中1井、顺1井、沙98井等岩心的系统观察,发现由于地震强度的不同,震积岩的垂向序列有所不同,地震越强烈,其震积岩序列的完整性越好,确定出震积岩的两种垂向序列。由于不同的震积岩构造特征对应不同的地震强度,因此进一步研究了各种震积岩构造与地震强度的关系。这些研究为塔里木盆地构造演化研究及震积岩的识别和描述提供了重要的地质理论依据,并可为研究该区古地震提供依据。

Character and Significance of Silurian Seismite in the Tarim Basin

Based on studies of regional tectonic setting and observation of drilling cores, seismite is recognized in Silurian strata of in the Tarim Basin. Many kinds of soft-sedimentary deformation structures are found in seismite, such as step micro-faults, pleate within layers, liquefaction sandstone and clay veins, vibrational liquefaction deformation structure and seismic breccias. Observation in drilling cores found that the sequence of seismite is different for the different seismic intensity, and the stronger the seismic intensity, the sedimentary sequence integrity of seismites gets better. Two kinds of seismite sequence are recognized. Because different seismite structures are formed in different seismic intensity, the relationship between seismite character and seismic intensity is studied. It provides a theoretical foundation for the tectonic evolution studies and seismite recognition in the Tarim Basin, and supplies evidence for research of paleo-seismicity.