山东鲁西地块断裂构造分布型式与中生代沉积—岩浆—构造演化序列  

FAULT DISTRIBUTION PATTERNS OF THE LUXI BLOCK,SHANDONG,AND MESOZOIC SEDIMENTARY-MAGMATIC-STRUCTURAL EVOLUTION SEQUENCE

作　　者：张锡明 张岳桥[2] 季玮[3] 

机构地区：[1]山东省第一地质矿产勘查院,山东济南250014 [2]中国地质科学院地质力学研究所,北京100081 [3]湖南省国土资源规划院省地质博物馆,湖南长沙410007

出　　处：《地质力学学报》2007年第2期163-172,共10页Journal of Geomechanics

基　　金：国家自然科学基金资助项目(批准号:40572120)部分成果

摘　　要：鲁西地块的断裂构造有两类不同分布型式：一类呈放射状分布，由陡倾、基底右行韧性剪切带和盖层内复杂力学性质的断裂组成；另一类呈环绕地块基底核部同心环状分布，由3个主要盖层伸展拆离带组成，主滑脱面分别位于古生界盖层与基底间的不整合面、石炭系与奥陶系之间的平行不整合面和中新生代断陷-沉积岩系与新生代火山-沉积物之间的断层。中生代构造变形样式可以分为3个层次：印支期褶皱-逆）中推覆构造、燕山中期NNE轴向的隔槽式箱状褶皱和燕山晚期NW、NNE向共轭正断-走滑断裂。相应地鲁西地块经历了3个成盆期，即早-中侏罗世、早白垩世和晚白垩世，这些中生代盆地在空间上的叠置导致了地块内部复杂的盆-山耦合关系。鲁西地块中生代有两个岩浆活动集中时期，即早侏罗世（约190Ma）和早白垩世（132～110Ma）。综合沉积记录、岩浆活动和构造变形过程，将鲁西地块中生代构造演化历史划分为6个阶段：晚三叠世挤压变形，早、中侏罗世弱伸展作用，中、晚侏罗世挤压变形与地壳增厚作用，早白垩世大陆裂谷与地壳伸展作用，早白垩世末期挤压变形与盆地反转事件和晚白垩世区域隆升。这些构造演化阶段和构造事件对研究和理解中生代构造、体制和深部岩石圈动力学转换过程具有重要意义。Faults in the Luxi block have two different distribution pattems： one is the radiate distribution pattern, and the other is the concentric circular distribution pattern, with faults encircling the core of the block basement. The former is composed of NW-striking, steep-dipping, basement dextral ductile shear zones and faults of complex mechanical nature in the cover sediments, and the latter consists of three major cover extensional detachment zones, with the main detachment surfaces lying at the unconformities between the Paleozoic cover and Precambrian basement, disconformities between the Carboniferous and Ordovician and faults between the Meso-Cenozoic downfauhing-sedimentary series and Cenozoic volcanicsedimentary rocks. Mesozoic structural styles include three levels： Indosinian overthrusts and folds, middle Yanshanian NNE-oriented box folds and late Yanshanian conjugate （NW and NNE）, normal to strike-slip faults. Accordingly, the Luxi block experienced three stages of basin formation, i. e. ： the Early to Middle Jurassic, Early Cretaceous and Late Cretaceous. The superimposition of these Mesozoic basins in space gave rise to a complex basin-mountain coupling relation inside the block. There were two periods of magmatic activity, i. e. the Early Jurassic （190-180Ma） and Early Cretaceous （132-110Ma）. By integrating the sedimentary records, magmatism and structural deformation, the Mesozoic structural history of the Luxi block may be divided into six stages： Late Triassic compression, Early to Middle Jurassic weak extension, Middle to Late Jurassic compression and crustal thickening, Early Cretaceous continental rifting and crustal extension, terminal Early Cretaceous compression and basin inversion event, and Late Cretaceous uplift. These structural evolution stages and events have great significance for the study and understanding of the Mesozoic structural regime transition and dynamic transformation in the deep interior of the lithosphere in eastern China.

关 键 词：鲁西地块 断裂构造型式 中生代 构造演化序列 构造体制转换 

分 类 号：P54[天文地球—构造地质学]