【摘要】 <正> 一、前言测区属政和县石屯公社富竹庄—马面山一带,福建省区测队(1972年)曾测制过地层剖面(图1),层位划归前震旦系建瓯群的一部分。这次我们对典型地段Ⅰ、Ⅲ(见图1)进行详细的岩性—构造编录,对地段Ⅱ及剖面两侧做了概略地质构造观测,对这里的岩性、变质程度、原岩、地层时代及变质期构造演化序列等问题进行初步研究。本文着重根据测区样品分析中所获微体古生物组合情况结合地质构造特征对地层时代进行探讨。更多还原

【Abstract】 The sequence under study in the present paper constitutes part of "Jianou Group" in North Fujian Province. However, whether the stratigraphic position of the sequence lies in the the Pre-Sinian Series or belongs to the Early Palaeozoic has been an academic problem being argued for quite a loug time. There are quartzite, granulite, dimicaceous quartz-schist plus dimicaceous schist containing staurolite and garnet, which are intercalated with such rock types as marble, hornblende schist as well as actinoliteand epidote-schist, exposed in the geologic sections surveyed. Metamorphic type is believed to belong to medium-pressure one. Metamorphism appears as ranging from east to west, embodied by transition from amphibolite facies to green schist facies,with the original rock composed mainly of normal sedimentary rocks. Metamorphic period underwent three episodes of folding deformations in various degrees, with the second deformation episode being the most drastic after the forming of crystalline schist. The analytical identification of impure marble, mica-quartz-schist and banded amphibolite, using leaching method, has resulted in the discovery of 8 genera and 9 species of micropalaeoplants, as well as of 10 Chitinozoa, in which there are several well-preserved fossils belonging to Mierhystridium as found the impure marble. The association aspects of microfossils found in this sequence are asimilar to those found in the Sinian System of East Yangtze Gorges. Chitinozoa are very tiny in body (only 35—75 u long ) ,displaying no ornamentatiou on vesicle wall, a sort of features asimilar to that of the Chitinozoa from the Sinian as reported both at home and abroad. Therefore, it is preliminarily concluded that the geological time of the metamorphic sequence under study should be dated back to Sinian Period.更多还原