广西石炭纪四射珊瑚的地理分布及组合特征

THE DISTRIBUTION AND ASSEMBLAGE OF CARBONIFEROUS TETRACORALLA IN GUANGXI

本文简要介绍了广西石炭纪四射珊瑚的地理分区、组合和地层分布概况。认为广西石炭纪四射珊瑚群落的构成和分布受沉积相和生物地理分区的双重控制。四射珊瑚的分布大致以右江断裂带为界。可分为两个大区,东北部区的珊瑚群由下到上可划分为7个组合带,西南部区可分为6个组合带。文章还提出造成广西早石炭世珊瑚群分布差异的原因是右江断裂带的控相作用。

1. The geographical distribution of Tetracoralla The distribution of Carboniferous Tetracoralla in Guangxi was controlled by both biogeographical provinces and sedimentary facies. In the early Early Carboniferous Tetracoralla was distributed in two areas, the northeastern area where Cystophrentis-Pseudouralinia occurred and the southwestern area where Uralinia-Humboldtia occurred, both of which were separated by the Youjiang Fault. In the late Early Carboniferous these two areas still existed, with Yunanophyllum-Kueichouphyllum distributed in the northeastern area and Melanophyllum-Palaeosmilia in the southwestern area. On the whole, the Early Carboniferous Tetracoralla fauna in the northeastern area is similar to those distributed in most areas of South China and can be named South China type Tetracoralla fauna, while the Tetracoralla fauna in the southwestern area is similar to those in Yunan, Tibet, and Europe and can be named Europe type Tetracoralla fauna. 2. The assemblage and stratigraphic distribution of Tetracoralla In the Early Carboniferous the Tetracoralla assemblage in the northeastern area was quite different from that in the southwestern area, but in the Late Carboniferous Tetracoralla assemblages in these two areas were almost the same. Seven assemblage zones have recognized in the northeastern area while six in the southwestern area. 3. A discussion on the causes of the difference between the Carboniferous Tetracoralla in different biogeographical areas (1) The influence of sedimentary environment Tetracoralla communities vary with sedimentary environment. ( 2) The influence of paleotectonic movement The long-term movement of the Youjiang Fault led to varince in sedimentary environments on both sides of the Fault and this in turn resulted in difference between Tetracoralla communities on both sides. ( 3) The influence of subsequent folding The transitional zone between two biogeographical areas may disappear because of compression during folding.