胶莱盆地白垩系林寺山组砾岩沉积特征及盆地演化意义  

Conglomerates on the Base Linsishan Formation of the Middle Early Cretaceous in Jiaolai Basin of Eastern Shandong,and Implications for Basin Evolution

作　　者：章朋[1,2] 旷红伟[1] 柳永清[1] 彭楠[1] 许欢[1] 汪明伟[3] 安伟[1] 王能盛[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]中国海洋石油总公司湛江分公司,广东湛江524057

出　　处：《沉积学报》2016年第1期15-32,共18页Acta Sedimentologica Sinica

基　　金：国家自然基金项目(41272021;41372109;90914003);中国地质调查局项目(1212011085477;12120114064301)~~

摘　　要：胶莱盆地下白垩统莱阳群底部林寺山组主要由砾岩组成。通过对盆地及周缘18个地点林寺山组砾岩系统的调查,从砾岩组分、砾径和长轴排列方向的统计分析出发,研究该砾岩沉积相类型、盆地物源区、古水流及林寺山组上覆地层中砂岩碎屑锆石U-Pb年龄谱特点,并进一步讨论了盆地演化的意义。研究表明,林寺山组底部砾岩以冲积扇相为主,但不同地点亚、微相类型又有差异。原型胶莱盆地由莱阳、海阳—即墨和诸城—五莲3个独立盆地组成,被6个隆起区所分隔。莱阳盆地的物源主要来自胶北隆起和苏鲁造山带北部;海阳—即墨盆地以苏鲁造山带北部隆起区、即墨—牟平隆起、胶南隆起为主物源区;诸城—五莲盆地以胶南隆起和马山—李党家低隆起为主要物源区。林寺山组砾岩的出现标志着苏鲁造山带大规模塌陷和胶莱盆地的形成。The Linsishan Formation,belonging to the bottom of the middl Early Cretaceous Laiyang Group in Jiaolai basin,Eastern Shandong,consists dominantly of a variety of conglomerates. Based on the petrological compositions,grain sizess and orientation of gravels within conglomerates at least 18 observation localities and a combination of detrital zircon dates of sandstones overlying the Linsishan Formation,this research reports a comprehensive results of the sedimentary facies,provenances,paleocurrents and implications of basin evolution. This study indicates that the Linsishan Formation mainly comprises of alluvial fan conglomerates with a variation of sedimentary microfacies in basin scale. The synsedimentary Jiaolai basin in term of paleogeography was constituted by three individual basins,i. e.,the Laiyang,Haiyang-Jimo and Zhucheng-Wulian basins,separated by the six paleo-uplifts. Provenance of the Laiyang basin are derived from Jiaobei uplift and the northern Sulu Orogenic Belt; source of the Haiyang-Jimu basin provided by northern Sulu Orogenic Belt,Jimo-Mouping uplift and Jiaonan uplift; Provenance of the Zhucheng-Wulian basin are derived from Jiaonan uplift and Mashan-Lijiadang low uplift. Finally,initiation of conglomerates of the Linsishan Formation in Eastern Shandong is a sign of formation of the synsedimentary Jiaolai basin and further,implies a largescale collapse of the Sulu Orogenic Belt resulted from vast extensional crustal detachment and lithosphere thinning in East China because of destruction of North China Craton.

关 键 词：胶莱盆地 白垩系 林寺山组 砾岩 沉积特征 盆地演化 

分 类 号：P534.53[天文地球—古生物学与地层学]