【摘要】 基于地表典型露头剖面观察、地震剖面和测井资料解释、沉降史分析,并运用叠合盆地和改造盆地的研究思路,恢复了胶莱盆地白垩纪不同演化阶段的盆地原型及其构造性质。结果表明,该盆地经历了3个显著不同的沉积-沉降阶段。早白垩世莱阳群沉积时期,盆地原型表现为两个NE至NNE向延伸的断陷槽:一个沿苴县—诸城断陷发育,另一个沿牟平—即墨构造带发育,其沉积-沉降中心分别受苏鲁造山带北缘断裂带和牟平—即墨断裂带控制;该阶段沉积-沉降速率发生显著的空间分异,最大沉积-沉降速率在断陷槽,为230～370m/Ma,沿两侧斜坡地带沉积-沉降速率减小,约60m/Ma。早白垩世青山群对应一套中基性至中酸性火山岩,在沂沭裂谷盆地中堆积了一套大盛群河湖相沉积,这个时期是典型的大陆裂谷作用阶段,胶莱盆地演化为火山盆地,盆地沉降速率为35～70m/Ma。晚白垩世盆地原型表现为受东西向断裂控制的不对称箕状断陷,由诸城凹陷、高密凹陷和莱阳凹陷组成,其构造性质属于受西侧郯庐断裂和东侧牟平—即墨断裂控制的右旋拉分盆地;该阶段沉积-沉降速率总体一致,在63～73m/Ma。最后探讨了白垩纪盆地不同伸展阶段的动力学机制。更多还原

【Abstract】 The prototype basin of the Jiaolai basin at different stages of its Cretaceous evolution and its tectonic origin have been reconstructed and determined based on the field observations of typical outcrop sections, interpretations of seismic profiles and borehole logging data and analysis of sedimentary and subsidence history of the Jiaolai basin and by following the principles and analytic methods for the study of modified and superimposed basins. The results show that the Jiaolai basin experienced three distinctive stages of sedimentation and subsidence during the Cretaceous. During the deposition of the Early Cretaceous Laiyang Group the prototype basin was mainly manifested by two NE-NNE-trending aulacogens: one developed along the Juxian-Zhucheng fault depression, and the other along the Mou-Ji fault zone. Their depocenters were controlled by the northern frontal fault zone of the Sulu orogenic belt and the Mou-Ji fault zone respectively. The deposition-subsidence rates during the stage underwent marked spatial differentiation. The maximum subsidence rates occurred along the axial zones of the aulacogens, reaching 200-350 m/Ma, and they decreased to ～60 m/Ma toward the slope zones on both sides. The Early Cretaceous Qingshan Group corresponds to a suite of intermediate-mafic to intermediate-acid volcanic rocks with a sequence of fluvio-lacustrine deposits of the Dasheng Group accumulated along the Yishu rift basin. This period was a stage of the typical continental rifting. The Jiaolai basin evolved to a volcanic basin, with a mean subsidence rate of 35-70 m/Ma. The prototype of the Late Cretaceous basin consisted of three half-grabens (i.e. the Laiyang, Gaomi and Zhucheng subbasins), whose subsidence was controlled by W-E-trending normal faults. These grabens were tectonically dextral pull-apart basins bounded on the west by the Tanlu fault and on the east by the Mou-Ji fault. During the stage the subsidence rates were relatively constant, being 63-73 m/Ma. Finally, the paper discusses the possible dynamic mechanisms in different stages of extension of this Cretaceous basin.更多还原