Chang - 2 oil - bearing beds of the yanchang formation , which is one of the most important oil - producing beds in the area , is mainly composed of braided river deposits with the meandering river existed only in the restricted northwest part of yanchang 延长地区上三叠统长2油层组是一套发育于浅水台地背景之下的陆源碎屑岩沉积，以辫状河河流相沉积为主，曲流河沉积仅在研究区西南角小面积分布。
Furthermore , eleven sedimentary subfacies are identified . respectively , the sedimentary subfacies are delta plain , delta front , prodelta , braided delta plain , braided delta front , braided prodelta , fan delta plain , fan delta front , fan prodelta , saucer lake and deep lake 并进一步识别出11种亚相，分别为：三角洲平原、三角洲前缘、前三角洲、辫状河三角洲平原、辫状河三角洲前缘、前辫状河三角洲、扇三角洲平原、扇三角洲前缘、前扇三角洲、浅湖和深湖。
Based on the detailed research on the sedimentary rocks of northwest ordos basin in their textures , structures , vertical sequences and logging response , six kinds of sedimentary facies can be recognized in this work , i . e . , alluvial fan , stream , fan delta , braided delta , delta , lake , barrier beach and carbonate platform , respectively , and more detailed classification of sedimentary subfacies and microfacies for each sedimentary facies are also made in the work 本文通过对鄂尔多斯盆地西北部沉积岩沉积结构、沉积构造、垂向序列及测井响应的深入研究，识别出冲积扇、河流、扇三角洲、辫状河三角洲、曲流河三角洲、湖泊、障壁海岸及碳酸盐台地等8种沉积相类型。在此基础上，对每一种沉积相又进行了详细的沉积亚相和微相的划分。
Sedimentary environment in benxi stage from east to west were respectively shallow - sea muddied continental shelf , barrier island , lagoon and tidal flat . most area in taiyuan stage was distributed by shallow - sea continental shelf , but the northern and southeastern part were scattered by clastic tidal flat and carbonate tidal flat . sedimentary environment in shanxi stage , in the middle and late shihezi stage was deltas and lake 马5晚期研究区发育蒸发台地相和局限台地相；本溪期自东而西发育浅海泥质陆棚、障壁岛、泻湖及潮坪相；太原期大部分地区发育浅海陆棚沉积，北部和西南部则发育碎屑岩潮坪和碳酸盐潮坪沉积；山西期和石盒子中晚期为三角洲和湖泊沉积环境；石盒子早期广泛发育辫状河三角洲和湖泊沉积。
To braided stream deposit , the fluvial sand body is distribute largely and continuously , so the heterogeneity is poor relatively , the relation of injection and production is better in the case of rare wells , about all wells have come on water , only in some thin sandbodys or bad physical layers there is some low flooded strata 对辫状河砂体，平面上大面积连续分布，在平面及层内非均质性弱，在较稀的井网下注采关系就较完善，目前平面上几乎所有井点都已水淹，只有局部由于砂体厚度变薄，物性相对变差而存在一些低水淹部位。
At the beginning of tiaohu period , the lake basin shrank , and the water became shallow . braided river facies and braided delta facies were found on both side of the basin , and deep lake facies disappeared , and shallow lake facies was only found in the southern of tiaohu seg and central part of malang seg 从中二叠世条湖期开始，湖盆发生萎缩，水体变浅，盆地南北两侧出现辫状河及辫状河三角洲相沉积，半深湖相消失，仅在条湖凹陷南缘及马朗凹陷中部残余滨浅湖相沉积。
By summarizing and analyzing the geological setting , uranium source , paleoclimate , hydrology , lithologic - lithofacies conditions in the region , it is indicated that the quantou formation in fanjiatun - jiutai area and the qingshankou formation in yangdachenzi area are potential metallogenic prospective areas for in - situ leachable sandstone type uranium deposit in the region , which develop braided channel or delta marginal sandstones , and possess favorable forming conditions of interlayer oxidation zone , and constituting supply - passage - discharge system of abundant uranium source 综合研究区域成矿地质背景、铀源、古气候、水文地质、岩性岩相条件，认为范家屯九台一带的泉头组及杨大城子一带的青山口组发育辫状河或三角洲前缘砂体，构成了铀源供应充足的补径排系统，具有有利的层间氧化带形成条件，是本区地浸砂岩型铀矿的有利成矿远景区带。
The good reservoir facies are braided stream and braided delta in alaer area , fan - delta in arhati area and lake - floor fan in shizigou - ganchaigou area . all of these areas are the main targets for oil exploration , it has discovered that there is an important unconformity between upper youshashan and lower youshashan formation of tertiary , on which there are a large amount of erosion and long time of depositional hiatues 在上述研究的基础上，对区内油气勘探的有利区带进行了预测，指出阿拉尔北东辫状河三角洲相带、阿哈提南东扇三角洲相带和狮子沟一干柴沟湖底扇相带为区内有利的储集相带，是今后勘探的主要目标。
2 , by detailed studying of sedimentary microfacies , guan 3 - 6 beds mainly belong to high crooked fluvial deposition system , and some parts of guan 5 - 6 show plait fluvial deposition system features : detailed divided them into edge beach , center beach and natural levee etc . 9 deposition microfacies and beach ridge and groove microficies 2 、通过沉积微相多层次逐级细分研究，认为馆3 - 6砂层组主要属于高弯曲度曲流河沉积体系，馆5 6部分小层表现为辫状河沉积体系；并细分出了边滩、心滩以及天然堤等九种沉积微相，以及滩脊和凹槽等微微相。
Besides , the sedimentary facies of upper ganchaigou and lower ganchaigou formation were also mapped in supersequences which are the main target strata for exploration . the high resolution sequence stratigraphic framework showed the genetic relationship between the distributions of sedimentary facies and their tectonic settings . the near - source sedimentary systems such as subaqueous alluvial fan and lake - floor fan are often deposed in rise - hemicycles in the steep slope background in the north , the coarse lithology of fan - delta prograded from north to south in fall - hemicycles , and the braided stream facies are formed in the rise - hemicycles in gentle slope background in the south , braided stream facies prograded from sorth to north in the fall - hemicycles , but the lacustrine facies and salt lake facies developed in the middle part of the area 详细的沉积相研究发现，红狮地区第三系发育有冲积扇、水下冲积扇、河流、三角洲、扇三角洲、湖泊和湖底扇7种主要沉积相类型，并对作为区内主要勘探目的层系的下干柴沟组和上干柴沟组进行了以超层序为单位的沉积相平面编图，以较高的时间分辨率揭示了区内沉积相带的平面展布及其在不同构造背景中的分布规律，比如在北部的凹陷陡坡背景下，上升半旋回低水位期通常发育有水下扇、湖底扇等陡岸近源特征的沉积体系，下降半旋回高水位期，扇三角洲相粗碎屑岩由北向南进积;在南部的凹陷缓坡背景下，上升半旋回主要发育辫状河流相，下降半旋回辫状河三角洲相由南向北进积;而中部红柳泉一狮子沟一带则为湖泊相沉积和盐类沉积。
