柴西侏罗系滑叠构造的几何学特征、成因及环境意义
DOI:
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

国家自然科学基金项目(面上项目,重点项目,重大项目)


Characteristics,Genesis, and Sedimentary Environment of Sliding Overlapping Structures in the Jurassic Sediments of Western Qaidam Basin, China
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    在柴达木盆地西部红沟子的侏罗系中发育了一种特殊的软沉积变形构造,与类双重构造和双曲构造有些相似,但又明显不同,除了叠片外,还有软变形褶皱及微型断层,这三者构成了滑叠构造的主体,我们把这种构造称之为“滑叠构造”。滑叠构造的主体是叠片,多呈直片状,少数呈“Z”形,有的尾部发育了燕尾构造或变形结。叠片的平均倾向301.2°,平均倾角54.71°。滑叠构造与软斜歪变形褶皱、砂岩岩脉、包卷层理等十余种软沉积变形构造一道产出。滑叠构造产在一套河道细砾岩、河道间炭质泥岩(页岩)、浅水三角洲砂泥岩、浅湖钙质泥岩、滑积岩和浊积岩序列中,其底部为棕红色的浅湖钙质泥岩和炭质泥岩,顶部为滑积岩,其成因密切与滑动牵引有关。结合其它共生、伴生构造认为滑叠构造是由地震引起的三角洲前缘半固结性沉积物沿滨浅湖沉积底层强力滑动牵引形成。滑叠构造的产状经过校正后平均倾向358°,倾角48°,指示滑动方向是自北向南,与目前阿尔金山的位置关系很匹配,也说明了侏罗纪是阿尔金山(可能是古隆起)就已经存在了。阿尔金山的造山作用在持续加强,并常常伴随地震作用,是滑叠构造形成的主要诱发因素。 滑叠叠片主要为分选很差的长石岩屑杂砂岩,有微弱变质, 层面可以见到绢云母. 滑叠构造产在一套河道细砾岩、河道间炭质泥岩 (页岩) 、浅水三角洲砂泥岩、浅湖钙质泥岩、滑积岩和浊积岩序列中, 其底部为棕红色的浅湖钙质泥岩和炭质泥岩, 顶部为滑积岩, 其成因密切与滑动牵引有关. 结合其它共生、伴生构造认为滑叠构造是由地震引起的三角洲前缘半固结性沉积物沿滨浅湖沉积底层强力滑动牵引形成的. 从滑叠构造的产状推测, 滑动方向是自北西301.2°向南东121°, 与目前阿尔金山的位置关系很匹配, 也说明了侏罗纪是阿尔金山(可能是古隆起)就已经存在了.

    Abstract:

    A particular type of soft-sediment deformation structure, similar to imbricate structure, is developed in the Jurassic strata at Honggouzi, western Qaidam Basin, China. We refer to this structure as a duplex-like deformation structure, because it is inferred to have been formed by the action of fast-moving, submarine gravity current sediments gliding across a pre-existing semiconsolidated sedimentary layer. Duplex-like structures are mainly being composed of a series of planar and horizontal laminations, which with the other regions all containing planar, horizontal laminations. However, a minority of the structures developed in the Jurassic strata of the Qaidam Basin have a “Z” shape, and at the bottom of the structure, there is a particular structure similar in shape to a swallow’s tail or soft-deformation nodule. The average dip direction of the duplex-like structure is 301.2° and the average dip angle is 54.7°. Duplex-like deformed laminations are composeizhi819d mainly of weakly metamorphosed, extremely poorly sorted, feldspathic lithic graywacke. Sericite can be observed along bedding planes. The duplex-like structure occurs within a sequence of river-channel fine conglomerate, interchannel carbonaceous mudstone (shale), shallow-water delta sand–shale, shallow-lake calcareous mudstone, olistostromes, and a turbidite. At the bottom of the sequence are found brownish-red shallow-lake calcareous mudstone and carbonaceous mudstone and at the top are found olistostromes whose genesis is related to the slip and drag of a slumped body of submarine sediment. In combination with other symbiotic and associated structures, it is considered that the duplex-like structure was formed by the slumping and subsequent movement and traction of delta-front semiconsolidated sediments over the bottom sediments of a shore or shallow-lake sedimentary environment, probably triggered by an earthquake. After correction, the average dip direction of the duplex-like structure is 358° and the average dip angle is 48°.The attitude of the duplex-like structure indicates that the direction of gliding was from north toward south, which is consistent with the current location of the Altun Mountains, indicating that the Altun Mountains existed in the Jurassic. The orogenesis of these mountains likely involved seismic activity, and an earthquake was the triggering factor in the formation of the duplex-like structure by causing the slumping/gliding of the olistostrome sediments.

    参考文献
    相似文献
    引证文献
引用本文

钟建华,倪良田,李勇,邵珠福,毛毳,刘圣鑫,孙宁亮,郝兵,陈彬.2015.柴西侏罗系滑叠构造的几何学特征、成因及环境意义[J].地质学报,89(8):1367-1379.
ZHONG Jianhua, NI Liangtian, LI Yong, SHAO Zhufu, MAO Cui, LIU Shengxin, SUN Ningliang, HAO Bing, CHEN Bin.2015. Characteristics, Genesis, and Sedimentary Environment of Sliding Overlapping Structures in the Jurassic Sediments of Western Qaidam Basin, China[J]. Acta Geologica Sinica,89(8):1367-1379.

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2013-10-18
  • 最后修改日期:2014-09-24
  • 录用日期:2015-08-11
  • 在线发布日期: 2015-08-12
  • 出版日期: