摘要
沙垒田凸起西部发育完整的受断裂陡坡带控制的源-汇系统.基于最新的钻井、薄片资料及高分辨率三维地震资料,精细刻画沙垒田凸起西部源-汇三要素(即物源体系、搬运体系及沉积体系),探讨要素间相关性并建立耦合模式.通过岩石学分析,物源区以混合花岗岩为主,结合古地貌恢复,划分4个三级汇水单元并定量拾取垂向高差与汇水面积参数,明确古沟谷与断槽物源通道的分布及尺度,应用地震沉积学精细刻画沙三段内部3个亚段扇三角洲沉积时空展布及演化.定量探讨源-汇各要素间的相关性,明确汇水单元面积与垂向高差是沉积扇体发育规模的主控因素,构建断裂陡坡带控制下的混合花岗岩-古沟谷或断槽与断面组合的物源通道-近源粗粒扇三角洲-浊积扇-湖泊体系耦合模式.
During the early stage of Palaeogene,western Shaleitian uplift and surrounding areas constituted a complete Sourceto-Sink system under the control of steep slope fault.We analyzed the characteristics of Source-to-Sink elements(provenance system,sediment-routing system,and sedimentary system),discussed the relativities among the three elements and established the coupling model of steep slope fault based on detritus,thin section and the geophysical response datain this study.Results show that the provenance of western Shaleitian uplifts was filled by Proterozoic metamorphic rocks.Based on the Paleogene palaeo-geomorphology,we divided the provenance into four third-order catchment units,obtained the quantitative parameters of height difference and catchment area,and confirmed the distribution and scales of incised valleys and faulted-troughsediment-transport pathways.The facies architecture and sediment-dispersal characters of fan-deltas system in the third member of Eocene Shahejie Formation have been analyzed by the stratal slice images.Quantitative analysis of the parameters in the sourceto-sink system show that the total sediment volume yielded by the eroded and weathered hinterland into the basin is closely related to the catchment area and the height difference of the hinterland.Then,the coupling model of source(migmatitic granite)-channel(incised valleys or fault-trough sediment-transport pathways)-sink(near-source coarse grain size fan delta-gravity flow-lake system)controlled by fault steep slopehas been established.
出处
《地球科学(中国地质大学学报)》
EI
CSCD
北大核心
2017年第11期1883-1896,共14页
Earth Science-Journal of China University of Geosciences
基金
中央高校基本科研业务费专项资金资助项目(No.CUG170653)
关键词
源-汇体系
断裂陡坡带
地震沉积学
沉积响应
沙垒田凸起
石油地质.
Source-to-Sink system
steep-slope fault
seismic sedimentology
sedimentary response
Shaleitian uplift
petroleum geology.