CAJ | 학술논문

北部湾盆地涠洲11区流一段发育缓坡型和陡坡型两种类型的扇三角洲。结合岩电震资料，分析了这两类扇三角洲的异同，并探讨了造成这两类扇三角洲沉积特征异同的主控因素。其中陡坡型扇三角洲主要分布于研究区北部陡坡带的流一段中亚段，粒度较粗，以重力流成因的厚层砂砾岩体为主，沉积厚度大，平面展布小；而缓坡型扇三角洲主要分布于研究区南部的涠西南低凸起缓坡带附近的流一段下亚段，粒度相对偏细，牵引流与重力流沉积构造均较发育，沉积厚度相对较小，平面延伸范围广。两类扇三角洲形成与分布特征的不同主要受控于构造格局、古地形的差异以及基准面变化等。
북부만분지위주11구류일단발육완파형화두파형량충류형적선삼각주。결합암전진자료，분석료저량류선삼각주적이동，병탐토료조성저량류선삼각주침적특정이동적주공인소。기중두파형선삼각주주요분포우연구구북부두파대적류일단중아단，립도교조，이중력류성인적후층사력암체위주，침적후도대，평면전포소；이완파형선삼각주주요분포우연구구남부적위서남저철기완파대부근적류일단하아단，립도상대편세，견인류여중력류침적구조균교발육，침적후도상대교소，평면연신범위엄。량류선삼각주형성여분포특정적불동주요수공우구조격국、고지형적차이이급기준면변화등。
Fan deltas of the abrupt slope and the gentle slope areas,were developed in the W1 1 area of 1 st Member of the Liushagang Formation in Southwestern Weizhou Depression,Beibuwan Basin.Based on the li-thology,logging and seismic data,the different characteristics between these two kinds of fan deltas were ana-lyzed and the main controlling factors of the fan delta were discussed.The fan deltas at abrupt slope area,which were mainly distributed at the steep slope zone of the middle part of 1 st Member of the Liushagang Formation in the northern of the study area,were comparatively coarse grain-sized and were mainly thick-layer sandstone rock deposited from the gravity flow,with large depositional thickness and small scale planar distribution.However, the fan deltas at gentle slope,which were widely distributed in the lower part of 1 st Member of the Liushagang Formation at Southwestern Weizhou Salient in the southern of the study area,had a mixed gravity flow and trac-tive current with relatively fine grain-sized,a small depositional thickness and a wide range of planar extension. The development and distribution of these two kinds of fan deltas were mainly controlled by structural frame-work,paleotopography and basal level change.