摘要
利用福建东南沿海地区城市活断层探测的研究资料,重新确认了福州、泉州和漳州盆地的断层组合与第四纪沉积。研究区内晚更新世"福州海侵"产生的炭质淤泥沉积现代高程的分析对比表明,晚更新世以来该区地壳发生不均匀隆升,而这些盆地相对于研究区内其他地区发生沉降。断层的静态位错理论研究认为,正断层深部活动引发地表的沉降,该区断裂的深部正断层活动是盆地沉降的重要因素。盆地的发展演化可划分为晚更新世以前的断陷阶段,和其间或其后的拗陷沉积阶段。
Utilizing the data of exploration of urban active fault in the south-east coast of Fujian Province,the fault groups and Quaternary sediments in Fuzhou,Quanzhou and Zhangzhou Basins are re-recognized. These basins are small in size. There are two groups of faults within and around the basins, most of which are buried. Their latest activity was before Late Pleistocene. The northwestern faults are the main and controlling faults. The sediments in basins are thin (several ten meters)and have deposited since Late Pleistocene. The paper mentions several sediments: Carbolic mud,beachrock, shell-sediment and " old red sand", which indicates the altitude of old sea-lever. The analysis and comparison of the present altitude of carbolic mud sediments of the "Fuzhou transgression" in this area indicated that the Earth's crust of the area has been upheaved unevenly. The modern altitude of the other sediments show similar results. In the basins the marine carbolic mud sediments are buried deeply, indicating that the basins have been subsided relatively to other areas since the Late Pleistocene during which the deposit has taken place. The regional tectonics of this area is controlled by northeastern and northwestern fault belts. The basins are generally located at the cross sites of two fault belts. The northwestern fault belt is more active. The lower part of the deep fault belts are sinistral tensional weakened belt. In upper layer of crust they act as the fault groups in the basins. The northwestern fault groups in the basins control the basins' evolvement. This area is adjacent to Taiwan, whose earthquake activity is almost the strongest in South China. The earthquake distribution is uneven The active intensity of coastal earthquakes is bigger than that of the inland; while the earthquake intensity of the south area is bigger than that of the north. These earthquakes took place mostly along the fault belts, especially at the cross sites of fault belts. According to static dislocation theory of fault, de
出处
《第四纪研究》
CAS
CSCD
北大核心
2009年第3期633-643,共11页
Quaternary Sciences
基金
福建省"十五"重点项目"福建省城市活断层探测和地震危险性评价"(批准号:48105-02-D18)资助
关键词
福建东南沿海
晚更新世海侵
盆地构造沉降
断裂深部活动
southeast coast of Fujian Province, Late Pleistocene transgression, tectonic subsidence of basins, deep activity of regional faults