论文部分内容阅读
牙形石的研究不仅对大套连续的海相地层时代划分十分重要,而且在确定火山岩的海相沉积夹层时代也能起重要作用.岞(山曲)组分布在河南淅川至内乡一带,自北西向南东呈楔状伸展,长达50km.岞(山曲)组是一套基性火山岩,主要是玄武玢岩、凝灰岩,可分为上下两段,为两期火山喷发所形成.下段顶部具透镜状中晶灰岩,为火山喷发间歇期的海相沉积.因此,确定这一喷发间歇期海相沉积的时代对于研究火山喷发时间及其它地质问题均具有重要意义.
The study of conodont is not only important for the classification of a large set of successive marine stratigraphic epochs but also plays an important role in determining the age of marine sedimentary dissemination of volcanic rocks. From northwest to south east was wedge-shaped extension, up to 50km. 岞 (mountain song) group is a set of basic volcanic rocks, mainly basaltic rock, tuff, can be divided into upper and lower sections, two volcanic eruptions formed by the lower section At the top is a lens-like medium-sized limestone, which is the marine sediment of the intermittent period of volcanic eruption, so determining the age of marine sediment during this eruption interval is of great significance for the study of volcanic eruption time and other geological problems.