二连盆地白音查干凹陷下白垩统腾格尔组沉积相

Sedimentary Facies in the Early Cretaceous Tenggeer Formation of Baiyinchagan Depression,Erlian Basin

根据岩心、电测曲线、录井、分析化验、地震等资料,研究了白音查干凹陷下白垩统腾格尔组沉积相类型和沉积特征,以及腾格尔组沉积相分布规律。结果表明,腾格尔组发育扇三角洲、辫状河三角洲、湖泊和浊积扇4种沉积相,扇三角洲分布在北部陡坡,辫状河三角洲分布南部缓坡,从盆地边缘到盆地中心,沉积相由扇三角洲、辫状河三角洲沉积渐变为半深湖—深湖相沉积,在三角洲侧翼发育滨—浅湖相沉积,在三角洲前缘以及前三角洲和半深湖中发育浊积扇,整体呈南北分异、东西分化,这种沉积格局受盆地周边断层和古地形控制。扇三角洲和辫状河三角洲前缘亚相带仍然是油气聚集的重要相带,而与断层相关的其前缘近岸浊积扇是岩性油气藏勘探的有利目标。

Based on cores＇ description, electric log, mud logging, cores＇ analysis data, seismic survey, etc. , the sedimentary facies＇ types and their characteristics of early Cretaceous Tenggeer Formation, Baiyinchagan （BYCG） Depression, were studied, as well as their distribution rule. The research showed that fan delta, braided channel delta, lacustrine facies, and turbidities were present in the formation, of which fan delta was located along the steep north border and braided channel delta in the gently south slope. In addition, from the margin to the depocenter of the depression, the sedimentary environments gradually changed from fan delta or braided channel delta to middle depth lacus and deep lacus, and on the flank of fan delta or braided channel delta were deposited shore sediments and meare sediments. The turbidities were distributed in the delta front zone as well as in the pro-delta and middle depth lacustrine zone. Generally speaking, the sedimentary facies were different from the east to the west of the depression and differentiated between the south and the north, which were controlled by the neighboring faults and the basin palaeotopography. The fronts of fan delta and braided channel delta are still the important hydrocarbon accumulation area, and the fauhs-related turbidities in them are the potential targets of exploring the lithological hydrocarbon reservoirs.