酸性火山成因的粘土岩在自然伽玛测井曲线上的显示及其在事件地层学上的应用

本文将自然伽玛测井资料试用在火山事件粘土岩层的研究中。根据现代自然伽玛测井技术水平和研究对象中放射性元素含量说明应用的可能性,分析沉积岩的物源与放射性元素含量的关系。非正常沉积岩中以酸性火山碎屑及其水解产物(粘土)含放射性元素较高。例举三种产状的火山成因粘土岩论证用自然伽玛测井资料寻找和研究火山事件粘土岩层的必要和优越性。笔者用此法发现川南筠连地区二叠三叠系地层之间存在界线粘土岩层。最后对自然伽玛测井技术发展远景提出设想。

THE MANIFESTATION OF CLAY ROCK OF ACIDIC VOLCANIC ORIGIN ON NATURAL GAMMA-RAY LOGGING CURVE AND ITS APPLICATION TO EVENT STRATIGRAPHY

This paper attempts to use natural gamma-ray logging data in the research of clay strata formed by volcanic events. The feasibility of this application is illustrated in the light of present technical level of natural gamma log-ging and contents of radiogenic elements in studied objects; the relations of material sources of sedimentary rocks with contents of radiogenic elements are analysed. Of all the uncommon sedimentary rocks, acidic volcaniolastic material and its hydrolyzates(clay)contain rather abundant radiogenic elements. With three types of volcanogenic clay rocks as examples, the natural gamma logging data are proved to be essential for finding and studying clay strata formed by volcanic events. Using this method, the author has found that there exists in Junlian area of southern Sichuan a layer of clay rocks between Permian and Triassic strata, which serves as the boundary of these two systems. Finally, some opinions are put forward concerning the ?future development of the natural gamma-ray logging technique.