腕足动物群落取代与海平面变化——以吐哈盆地南缘雅满苏石炭系西大沟剖面为例

吐哈盆地南缘雅满苏西大沟剖面石炭系含有丰富的腕足动物化石,可划分为8个群落和1个搬运化石集合。个体生态、行为习性、营养结构的分析及岩性、岩相组合特征的研究表明:这些群落的生态位界于BA2和BA3之间,缺乏BA4和BA5较深水群落,说明该区石炭纪海水深度不超过60m。各群落自身演替的主要控制因素是生物之间的相互作用。各群落在时间上相互取代的主要控制因素为海水深度,与该区石炭纪4次明显的海水进退三级旋回密切相关,其中第二旋回的影响最为明显,并形成了白鱼山组顶部的不整合面。控制该区相对海平面变化的主要原因可能是石炭纪发生的4次构造运动,其次是全球海平面变化。

THE RELATIONSHIP BETWEEN THE REPLACEMENT OF BRACHIOPODS COMMUNITIES AND THE RELATIVE SEA LEVEL CHANGES:A CASE STUDY OF THE XIDAGOU CARBONIFEROUS SECTION IN YAMANSU OF THE SOUTH MARGIN OF THE TUHA BASIN

Abundant Carboniferous brachiopod fossils from the Xidagou section of Yamansu in the south margin of the Turpan-Hami basin were collected, and 8 communities and 1 transport fossil aggregate were recognized. According to a detailed study on individual morphology, ethology and nourishment structures, integrated with the analysis of lithology and sedimentary facies, the eco positions of these communities distribute mainly between BA2 and BA3. In addition, no BA4 or BA5 community is found in the region, indicating the biggest depth of seawater under 60 m. The main factors, which dominate the existence and successions of these communities, are the seawater depth, substrata characteristics, hydropower intensities and frequent volcanoes. In Carboniferous, replacements of the communities are closely related to the 4 third order cycles of sea level changes mainly controlled by the mid Hercynian Movement. 