锆石裂变径迹年龄对济阳坳陷新生界源区构造背景的指示意义  

Indicating significance of Cenozoic zircon fission track ages of the Jiyang depression to its provenance and tectonic background

作　　者：刘士林[1,2] 肖焕钦[3] 林舸[2] 郑和荣[1] 王毅[1] 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [2]中国科学院广州地球化学研究所,广州510640 [3]中国石化胜利油田,山东东营257060

出　　处：《地质科学》2012年第1期240-250,共11页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家自然科学基金项目(编号:40773004)资助

摘　　要：沉积物中的锆石裂变径迹分析可以用于示踪沉积盆地的源区性质及其构造演化信息。济阳坳陷新生界9块砂岩样品的锆石裂变径迹中值年龄介于183.1±15.0 Ma～100.0±5.6 Ma之间,锆石单颗粒年龄均大于其地层沉积年龄。对没有通过x^2检验的6块样品进行了多组分年龄分离分析,表明多数样品主要由2个年龄组分组成。总体上,砂岩锆石裂变径迹单组分年龄具有较好的一致性,主要介于389.1±5.1 Ma～272.7±14.6 Ma(P1)、238.1±7.8 Ma～203.6±6.6 Ma(P2)、179.3±13.9 Ma～96.8±17.8 Ma(P3)、80.3±15.7 Ma～55.3±6.0 Ma(P4)之间。这4组年龄组分分别记录了晚古生代、三叠纪、晚侏罗—早白垩世及晚白垩世—古新世时期内锆石裂变径迹完全退火时的年龄。结合区域地质背景认为,济阳坳陷新生界的主要物源是燕山运动中期强烈的构造岩浆活动期内发育的上侏罗统下白垩统的火山岩和火山—碎屑岩系;海西期、印支期以及燕山晚期—喜马拉雅山早期过渡时期的构造岩浆活动也对坳陷有少量物源贡献。Zircon fission track analyses of sediments of sedimentary basins can be used to trace its provenance characters and tectonic evolutional history.Central ages of zircon fission tracks of 9 Cenozoic sandstones from the Jiyang depression arrange from 183.1±15.0 Ma to 100.1±5.6 Ma,and all the single zircon grain age is bigger than its strata depositional age.Multiple component analyses of zircon fission track ages were calculated to the 6 samples which were not passed by χ2-Test,and the results show that most sandstone samples mainly consist of two age components.As a whole,single component of zircon fission track ages of the 9 sandstones show a good coherence,and these can be concluded into four components which arranges from 389.1±5.1 Ma to 272.7±14.6 Ma（P1）, 238.1±7.8 Ma to 203.6±6.6 Ma（P2）, 179.3±13.9 Ma to 96.8±17.8 Ma（P3）,and 80.3±15.7 Ma to 55.3±6.0 Ma（P4）respectively.The four components record the entire annealing ages of zircon grains in the Late Paleozoic,Triassic,Late Cretaceous-Paleocene and Early Cretaceous respectively.Combined with regional geological background,it can be concluded that volcanic rocks and volcano-clastic rocks of the Upper Jurassic to Lower Cretaceous strata which were formed due to the intense tectono-magmatic activation of the Middle Yanshannian Movement are the chief provenance to Cenozoic strata of the depression; meanwhile,the tectono-magmatic activations which are attributed to the Hercynian,the Indosinian,and the Late Yanshannian to Early Himalaya Movements also have a few provenance contribution to those of the Jiyang depression.

关 键 词：锆石裂变径迹 物源 构造演化 济阳坳陷 

分 类 号：P588[天文地球—岩石学] P597[天文地球—地质学]