CAJ | 학술논문

鄂尔多斯盆地中部石炭二叠系发育曲流河浅水海相三角洲和网状河浅水湖泊三角洲两种类型的三角洲。这两类三角洲与经典的三角洲模式不同的是，三角洲前缘水下分流河道砂体和三角洲平原分流河道砂体分别构成了曲流河浅水海相三角洲和网状河浅水湖泊三角洲的骨架砂体，而不是传统认为的三角洲前缘河口砂坝。控制石炭二叠系两类三角洲发育的主要是河流类型、地形坡度、水体深浅、不同水体密度差及河流沉积作用和湖泊的分散作用等。曲流河浅水海相三角洲主要发育于曲流河水系，沉积物较细，地形坡度平缓，喷流机制为似等密度流，水体密度较大，以河流、波浪和潮汐作用为主；网状河浅水湖泊三角洲主要发育于网状河水系，沉积物较粗，地形坡度较小，喷流机制属高密度流，水体密度较小，湖泊分散作用较强，沉积作用相对较弱。根据两类三角洲的特征分别建立了它们的沉积模式，并指出曲流河浅水海相三角洲前缘水下分流河道砂体及网状河浅水湖泊三角洲的平原相带呈透镜状或带状分布的分流河道砂体是有利的勘探方向和目标。
악이다사분지중부석탄이첩계발육곡류하천수해상삼각주화망상하천수호박삼각주량충류형적삼각주。저량류삼각주여경전적삼각주모식불동적시，삼각주전연수하분류하도사체화삼각주평원분류하도사체분별구성료곡류하천수해상삼각주화망상하천수호박삼각주적골가사체，이불시전통인위적삼각주전연하구사패。공제석탄이첩계량류삼각주발육적주요시하류류형、지형파도、수체심천、불동수체밀도차급하류침적작용화호박적분산작용등。곡류하천수해상삼각주주요발육우곡류하수계，침적물교세，지형파도평완，분류궤제위사등밀도류，수체밀도교대，이하류、파랑화조석작용위주；망상하천수호박삼각주주요발육우망상하수계，침적물교조，지형파도교소，분류궤제속고밀도류，수체밀도교소，호박분산작용교강，침적작용상대교약。근거량류삼각주적특정분별건립료타문적침적모식，병지출곡류하천수해상삼각주전연수하분류하도사체급망상하천수호박삼각주적평원상대정투경상혹대상분포적분류하도사체시유리적감탐방향화목표。
Two Kinds of deltas-meandering stream-shallow sea delta andbraided stream-shallow lake delta-developed in Permo-carboniferous Systems in Ordos Basin.The deltas differ from typical deltaic model.Deltaic front subaqueous distributary channel sand bodies and deltaic plain distributary channel sand bodies are the skeleton sand bodies of meandering stream-shallow sea delta and braided streain-shallow lake delta respectively but not tranditional deltaic front river mouth sand bars.The two kinds of deltas are controlled by river types,ground slope,water depth,water density differentia,river sedimentation and lake dispersion.The first kind of delta mainly developed in meandering stream water system;the second kind of delta developed in braided river water system.Two depositional models were built according to their characteristics.It is pointed out that the subaqueous distributary channel sand bodies of the first type of delta and the lensing and zonal distributary clannel sand bodies of the second type are favourable oil and gas exploration targets.