塔里木盆地现代分支河流体系形态、分布及其主控因素  

Morphology,distribution and main controlling factors of modern distributive fluvial system in Tarim Basin

作　　者：孟庆昊 张昌民[1] 张祥辉 朱锐[1] 向建波 MENG Qinghao;ZHANG Changmin;ZHANG Xianghui;ZHU Rui;XIANG Jianbo(School of Geosciences,Yangtze University,Wuhan 430100,China)

机构地区：[1]长江大学地球科学学院,武汉430100

出　　处：《岩性油气藏》2024年第4期44-56,共13页Lithologic Reservoirs

基　　金：国家自然科学基金重点项目“分支河流体系沉积模式与储层定量预测模型”(编号:42130813)资助。

摘　　要：结合野外地质考察成果,运用地理信息软件测量了塔里木盆地及其周缘发育的分支河流体系(DFS),对比盆地不同区域DFS几何形态参数差异,以探究DFS发育规律及其主控因素。研究结果表明:(1)塔里木盆地沉积体系划分为DFS、轴向沉积体系、沙漠沉积体系及其他沉积体系4种类型,DFS总面积占比最高,约为36%,主要发育在南天山山前区、昆仑山山前区以及阿尔金山山前区3个区域。(2)盆地DFS可划分为小型、大型、巨型3种类型,昆仑山山前区DFS发育规模最大,阿尔金山山前区其次,南天山山前区最小。规模大的DFS控制着盆地DFS格局,在测量的846个DFS中,盆地小型DFS数量占比高达89.4%,总面积占比5%;巨型DFS数量占比为2.2%,总面积占比达68%。(3)DFS几何形态主要参数包括面积、半径、坡度。面积与半径拟合优度R2为0.966 4,具有较强的正相关性;坡度与半径拟合优度R2为0.463 0,具有一定程度的负相关性;坡度与面积拟合优度R2为0.498 8,具有一定程度的负相关性。(4)DFS形态及分布的主控因素包括气候、水文、构造隆升程度。极端干旱的气候条件下,河流更易干涸,DFS发育规模受到限制;DFS半径与河流径流量相关性较强,河流径流量越大,DFS发育规模越大;构造隆升程度起主导作用,山体隆升越大,越容易发育更大规模的DFS。盆地内部负向构造单元促进DFS发育,正向构造单元阻碍DFS发育。Combined with the results of field geological investigation,the geographic information software was used to measure the distributive fluvial system(DFS)developed in and around Tarim Basin,and the differences in geometric parameters of DFS in different regions of the basin were compared to study the development rules and main controlling factors of DFS.The results show that:(1)The sedimentary system of Tarim Basin can be divided into four types:DFS,axial sedimentary system,desert sedimentary system and other sedimentary systems.The DFS has the highest proportion,accounting for about 36%,and mainly developed in south Tianshan Mountain piedmont area,the Kunlun Mountain piedmont area and the Altun piedmont area.(2)The DFS in Tarim Basin can be divided into three types:small,large and mega DFS,with the largest scale of DFS deve-loped in the Kunlun Mountain piedmont area,followed by Altun Mountain piedmont area,and the smallest scale in the south Tianshan Mountain piedmont area.Large-scale DFS controls the pattern of DFS.Among the 846 measured DFS,the proportion of small-scale DFS in the basin is 89.4%,and the total area accounts for 5%.The proportion of mega DFS is 2.2%,and the total area accounts for 68%.(3)The main geometric parameters of DFS include area,radius,and slope.The goodness of fit R2 between area and radius is 0.9664,indicating a strong positive correlation.The goodness of fit R between slope and radius is 0.4630,indicating a certain degree of negative correlation.The goodness of fit R22 between slope and area is 0.4988,indicating a certain degree of negative cor‐relation.(4)The main controlling factors for the morphology and distribution of DFS include climate,hydro-logy and tectonic uplift degree.Under extreme arid climate,rivers are more likely to dry up,and the development scale of DFS is limited.The river runoff of DFS has a strong correlation with radius,and the larger the river run‐off,the larger the scale of DFS development.The degree of tectonic uplift plays a dominant role,and the higher the

关 键 词：分支河流体系 河流扇 巨型扇 几何形态 构造隆升程度 负向构造单元 正向构造单元 第四纪 塔里木盆地 陆相盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]