南海北部陆坡神狐海域GMGS01区块细粒浊积体的识别特征及意义

发布时间：2018-01-12 22:14

本文关键词：南海北部陆坡神狐海域GMGS01区块细粒浊积体的识别特征及意义　出处：《海洋地质与第四纪地质》2017年05期 　论文类型：期刊论文

【摘要】：利用广州海洋地质调查局在神狐海域采集的高分辨率地震数据,结合2007年第一次水合物钻探航次(GMGS01)获取的岩心资料,从地震反射结构和岩心粒度特征两个方面对GMGS01区块内残留在峡谷群脊部的细粒浊积体进行了识别和特征刻画。过水合物钻探站位的准3D地震剖面显示,GMGS01区块似海底反射(bottom simulating reflectors,BSR)之上的沉积体表现为2套特征迥异的反射单元:位于下部的薄层透镜状的杂乱反射单元,位于上部的厚层波状起伏形态的连续性中—强振幅反射单元。实际钻获岩心的粒度分析结果表明,沉积物的粒度为4~63μm,为细粒的粉砂或粉砂质泥。自下而上,沉积物的岩性和粒度特征没有发生大的变化,较为相似。但通过粒度CM图,可以发现,含水合物层段与不含水合物层段的沉积物表现为不同的特征,含水合物层段沉积物的结果近似与C=M基线平行,暗示了细粒浊积体的存在。结合神狐海域区域性覆盖的2D地震资料,研究认为发育在神狐海域北部的一系列小型水道,将会侵蚀下部地层的沉积物,使其沿着陆坡坡降的方向发生自北向南的再次搬运,在中—下陆坡的位置以细粒浊积体的形式再次沉积下来。神狐海域细粒浊积体的识别,将为从深水沉积的角度探讨GMGS01区块内水合物的不均匀性分布提供依据,从而有助于进一步揭示该区域水合物的成藏机制和富集规律。
[Abstract]:Based on the high resolution seismic data collected by Guangzhou Marine Geological Survey in Shenhu sea area and the core data obtained from the first hydrate drilling voyage GMGS01 in 2007. The fine turbidite remained in the ridge of the gorge group in GMGS01 block is identified and characterized from the aspects of seismic reflection structure and grain size characteristics of the core. Quasi-3D seismic profile of gas hydrate drilling station. Show. GMGS01 block is like bottom simulating reflectors. The deposits on the BSRs show two sets of reflectance units with different characteristics: the thin-layer lenticular scattered reflectors located in the lower part. The continuity of wave-like undulate form of thick layer in the upper part is medium to strong amplitude reflection unit. The grain size analysis results of the actual drilling core show that the grain size of the sediment is 463 渭 m. From bottom to top, the lithology and grain size characteristics of sediment have not changed greatly and are similar, but can be found by means of grain size CM diagram. The sediments of the hydrate layer and the layer without hydrate show different characteristics, and the results of the sediment in the hydrate layer are approximately parallel to the Cumm baseline. Combined with 2D seismic data of Shenhu sea area, it is believed that a series of small waterways developed in the northern part of Shenhu sea area will erode the sediments in the lower strata. It is transported again from north to south along the direction of slope downhill, and is deposited again in the form of fine-grained turbidite in the position of middle-lower slope, and the recognition of fine-grained turbidite in Shenhu sea area. It will provide a basis for the discussion of the distribution of hydrate heterogeneity in GMGS01 block from the point of view of deep-water deposition, which will be helpful to further reveal the mechanism of hydrate formation and the law of gas hydrate enrichment in this area.
【作者单位】：中国地质大学(北京)海洋学院;中国科学院天然气水合物重点实验室中国科学院广州能源研究所;中山大学海洋科学学院;中国地质调查局广州海洋地质调查局;国土资源部天然气水合物重点实验室中国地质调查局青岛海洋地质研究所;
【基金】：国家自然科学基金项目(41576048) 油气藏地质及开发工程国家重点实验室(成都理工大学)开放基金(PLC201407) 广州市珠江科技新星(201710010198) 中国石油-中国科学院科技合作项目(2015A-4813)
【分类号】：P618.13;P744.4
【正文快照】： 位于南海北部陆坡区域的神狐海域是我国海域天然气水合物勘探的重要区域之一,自20世纪90年代开始,国土资源部广州海洋地质调查局在该区域进行了大量的地质、地球物理和地球化学调查航次,并圈定了水合物的可能富集区域。2007年在神狐海域进行了我国首个海域水合物的钻探(GMGS01

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