超临界沉积物重力流形成演化及特征
发布时间：2018-08-21 11:09
【摘要】：超临界沉积物重力流是指在深水环境中弗洛德数大于1,沿水下斜坡向盆地中心搬运、在水力跳跃机制作用下发生超临界流与亚临界流频繁转化、形成易于保存的大型波状旋回坎的高密度流。超临界沉积物重力流作用的沉积识别标志主要包括牵引毯作用形成的分层构造,即后积层理、短波状上攀交错层理、假前积层等层理构造;水力跳跃作用形成的侵蚀和软沉积物变形构造等局部识别标志和旋回坎综合识别标志。理想条件下,超临界沉积物重力流作用在垂向上由下至上形成砾质旋回坎、砾质流槽-凹坑沉积充填、砂质不稳定逆行沙丘沉积、砂质分层沉积和沙纹沉积及正常沉积的有序组合。旋回坎可分为侵蚀型和沉积型,从盆地边缘向盆地中心,呈现侵蚀型向沉积型的演化。超临界沉积物重力流作用沉积演化过程主要受流体沉积物浓度、流体流量、沉积物粒度、沉积速率等内部因素和地形坡度、坡折带位置、水深及可供侵蚀的沉积物特征等外部因素的综合控制。超临界沉积物重力流作用的相关研究加深了对沉积物重力流水道形成机理、深水块状粗碎屑成因、重力流沉积演化过程的认识;现阶段关于超临界沉积物重力流的流体动力学特征、沉积识别标志及形成演化过程的系列问题还有待深入研究。
[Abstract]:Supercritical sediment gravity flow refers to the high-density flow which occurs frequently under the action of hydraulic jump mechanism when the Froude number is greater than 1 in deep water environment and moves along the underwater slope to the center of the basin. The sedimentary identification marker of supercritical sediment gravity flow is the main one. It includes the stratified structure formed by traction blanket, such as post-accumulated bedding, short-wave cross-climbing bedding, pseudo-pre-accumulated bedding, erosion formed by hydraulic jumping and deformation structure of soft sediment, and comprehensive identification marks of cyclic ridge. Up to the top, a conglomerate cyclic ridge, a conglomerate flow trough-pit sedimentary filling, an unstable sand retrograde dune deposit, a stratified sand deposit, a sand ripple deposit and an orderly combination of normal deposits are formed. The process of sedimentary evolution is mainly controlled by internal factors such as fluid sediment concentration, fluid flow, sediment grain size, sedimentary rate, topographic gradient, slope break location, water depth and erodible sediment characteristics. Mechanisms, genesis of deep-water massive coarse debris, and understanding of the sedimentary evolution of gravity flow. At present, the hydrodynamic characteristics of supercritical sediment gravity flow, sedimentary identification markers and a series of problems in the process of formation and evolution need to be further studied.
【作者单位】： 中国石油大学地球科学与技术学院;海洋国家实验室海洋矿产资源评价与探测技术功能实验室;
【基金】：国家重大科技专项(2016ZX05006-007) 中央高校基本科研业务费专项资金项目(14CX06070A)资助
【分类号】：P512.2
[Abstract]:Supercritical sediment gravity flow refers to the high-density flow which occurs frequently under the action of hydraulic jump mechanism when the Froude number is greater than 1 in deep water environment and moves along the underwater slope to the center of the basin. The sedimentary identification marker of supercritical sediment gravity flow is the main one. It includes the stratified structure formed by traction blanket, such as post-accumulated bedding, short-wave cross-climbing bedding, pseudo-pre-accumulated bedding, erosion formed by hydraulic jumping and deformation structure of soft sediment, and comprehensive identification marks of cyclic ridge. Up to the top, a conglomerate cyclic ridge, a conglomerate flow trough-pit sedimentary filling, an unstable sand retrograde dune deposit, a stratified sand deposit, a sand ripple deposit and an orderly combination of normal deposits are formed. The process of sedimentary evolution is mainly controlled by internal factors such as fluid sediment concentration, fluid flow, sediment grain size, sedimentary rate, topographic gradient, slope break location, water depth and erodible sediment characteristics. Mechanisms, genesis of deep-water massive coarse debris, and understanding of the sedimentary evolution of gravity flow. At present, the hydrodynamic characteristics of supercritical sediment gravity flow, sedimentary identification markers and a series of problems in the process of formation and evolution need to be further studied.
【作者单位】： 中国石油大学地球科学与技术学院;海洋国家实验室海洋矿产资源评价与探测技术功能实验室;
【基金】：国家重大科技专项(2016ZX05006-007) 中央高校基本科研业务费专项资金项目(14CX06070A)资助
【分类号】：P512.2
【参考文献】
相关期刊论文 前10条
1 YANG Tian;CAO Yingchang;WANG Yanzhong;;A new discovery of The Early Cretaceous Supercritical Hyperpycnal Flow Deposits on Lingshan Island,East China[J];Acta Geologica Sinica(English Edition);2017年02期
2 操应长;杨田;王艳忠;张少敏;王思佳;张青青;王心怿;;深水碎屑流与浊流混合事件层类型及成因机制[J];地学前缘;2017年03期
3 袁静;梁绘媛;梁兵;董道涛;闵伟;宋t，
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