摘要:江南断裂带在安徽境内沿东至、石台、泾县到宣城一线呈NE向分布,野外主要表现为构造角砾岩破碎带和一系列逆冲推覆断裂;其布格重力异常显示断裂深处产状逐渐变缓,具有向SE向偏移的特征;从寒武纪到晚泥盆世时期控制了断裂两侧的岩性和沉积环境。通过对其野外构造现象、地球物理、岩相古地理的分析和研究,认为江南断裂带(安徽段)是一个多期活动的深大断裂:加里东期,断裂开始发育;该断裂从寒武纪到晚泥盆世时期控制了断裂两侧的岩性、沉积相、沉积环境的不同,表现为同沉积活动断层的性质;印支期断裂主要表现为由南向北的逆冲推覆及顺层剪切作用;燕山早期主要为一系列由SE向NW逆冲推覆构造及脆性断裂;燕山晚期,断裂主要表现正断层及平移断层的特征;喜山期,断裂以正断层活动为特征。
关键词: 江南断裂带/
构造特征/
布格重力异常/
岩相古地理
Abstract:The Jiangnan fault zone in Anhui Province distributes in NE direction along the east to Shitai, Jingxian and Xuancheng lines. The field mainly shows structural breccia fracture zone and a series of thrust nappe faults. The Bouguer gravity anomaly shows that the occurrence of deep faults gradually slows down and has the characteristics of SE migration. The lithology and sedimentary environment on both sides of the fault were controlled from Cambrian to Late Devonian. Based on the analysis and study of its field tectonic phenomena, geophysics and lithofacies palaeogeography, it is considered that the Jiangnan fault zone (Anhui section) is a deep and large fault with multi-stage activity:in Caledonian period, faults began to develop; the faults controlled the differences of lithology, sedimentary facies and sedimentary environment on both sides of the fault from Cambrian to Late Devonian period, showing the characteristics of synsedimentary active faults. The Indosinian faults are mainly characterized by S-N thrusting and bedding shearing; the Early Yanshanian faults are mainly a series of SE-NW thrusting nappe structures and brittle faults; the Late Yanshanian faults are characterized by normal faults and translation faults; and the Himalayan faults are characterized by normal fault activity.
Key words:Jiangnan fault/
Structural characteristics/
Bouguer gravity anomaly/
Lithofacies paleogeography
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