摘要
赣西北幕阜山—九岭山一带中元古界双桥山群是一套被震旦系不整合覆盖、成层有序的正常沉积地层。其内近东西向褶皱 (同构造期热液事件 )叠加早期近南北向褶皱为华夏板块与扬子板块碰撞拼贴过程中在板内留下的痕迹 ,板内构造与拼贴带为同期构造运动形成的不可分割的统一体。根据侵位于东西向褶皱核部的漫江单元、山口单元 (斜长花岗岩 )单颗粒锆石直接蒸发年龄 (分别为 84 6± 7Ma与 80 5± 75Ma) ,以及与东西向褶皱伴生的古断裂特征等证据表明 :该区构造变形至少发生在 80 0Ma之前的前震旦纪 ,可能与格林威尔运动相当 。
The middle Proterozoic Shuangqiaoshan Group in area of Mufu and Jiuling Mountains, Northwest Jiangxi is a set of normal sedimentary strata with obvious sequence and is covered by the Sinan with an unconformity. The nearly S-N folds formed early were modified by the nearly E-W folds and synchronous tectonic heat fluid event which is the intraplate trace of the collision between the Yangtze and Cathaysia plates. The intraplate tectonics and amalgamation belt occurred in a synchronous tectonic movement. K-Ar dating of single mineral of diorites from the Manjiang and the Shanko units which intruded into the E-W folds give ages of 846±7 Ma and 805±75 Ma respectively. The palaeo-faults are the companions of the E-W folds. These evidences suggest that the tectonic deformation occurred in the Precambrian before 800 Ma corresponding approximately to the Grenville movement and the existence of the Jiangnan Ancient Land.
出处
《高校地质学报》
CAS
CSCD
2003年第1期81-88,共8页
Geological Journal of China Universities
基金
国家地质调查项目:江西港口幅
三都幅
修水县幅
马坳幅 1:5万图组及江西征村幅
山口街幅 1:5万图组资助
关键词
九岭山
双桥山群
前震旦纪
构造变形
江南古陆
江西
Jiuling Mountain
Shuangqiaoshan Group
Precambrian
tectonic deformation
Jiangnan Ancient Land
