从构造运动谈地质年代表的划分方案

地球的发展进入“地质时期”以来,岩石圈(首先是地壳)、大气圈、水圈和生物圈等外部圈层,相继形成并在内外动力作用下不断演化。这种演化过程,以不同程度和不同形式保留在不同时期形成的地质体上。我们正是通过对具体地质体的研究,从中抽象出它们形成的相对顺序和时限概念,逐步建立起地质年代表。因此,随着研究的深入,地质年代表也将不断被补充和修正。一般说来,前寒武纪地层受后期改造较强烈,地质年代表的这一部分就有着较大的分歧和争论,世界各地的地质学家提出过多种划分方案。

A DISCUSSION ON THE GEOLOGICAL TIME SCALE IN THE LIGHT OF TECTONIC MOVEMENTS

Based on the new materials collected in compiling The marine and Continental Tectonic map of China and its Environs, we suggested a new regional scheme of geological time scale.It is believed that tectonic cycles usually change environments of the outer spheres of the earth and control the evolution of organisms. Therefore, the major tectonic movements, particularly in their climax of activity, often take place earlier than the variations of biological evolution.At about 1800-2000 m.y. ago appeared significant changes in the crustal evolution accompanied by strong tectono-thermal event, which further showed a great effect on the composition of atmosphere and ocean, the facies of sedimentary formations and the type of organic metabolism. It is thus proposed to adopt the term of "Eozoic Era", the duration of which lasted from about 1000 m.y. to 900 m.y. before present.Following A. W. Graban, we insist that the Sinian is a transitional period between the Eozoic and the Paleozoic in the evolution of organism, it implies an important stage of biological developments. In the light of the tectonic cycles, the Sinian has a closer relation to the Paleozoic and can be regarded as its beginning period.