朱林, 傅命佐, 刘乐军, 李家钢, 高珊. 南海北部白云凹陷陆坡海底峡谷地形地貌与沉积地层特征[J]. 海洋地质与第四纪地质, 2014, 34(2): 1-9. DOI: 10.3724/SP.J.1140.2014.02001
引用本文: 朱林, 傅命佐, 刘乐军, 李家钢, 高珊. 南海北部白云凹陷陆坡海底峡谷地形地貌与沉积地层特征[J]. 海洋地质与第四纪地质, 2014, 34(2): 1-9. DOI: 10.3724/SP.J.1140.2014.02001
ZHU Lin, FU Mingzuo, LIU Lejun, LI Jiagang, GAO Shan. CANYON MORPHOLOGY AND SEDIMENTS ON NORTHERN SLOPE OF THE BAIYUN SAG[J]. Marine Geology & Quaternary Geology, 2014, 34(2): 1-9. DOI: 10.3724/SP.J.1140.2014.02001
Citation: ZHU Lin, FU Mingzuo, LIU Lejun, LI Jiagang, GAO Shan. CANYON MORPHOLOGY AND SEDIMENTS ON NORTHERN SLOPE OF THE BAIYUN SAG[J]. Marine Geology & Quaternary Geology, 2014, 34(2): 1-9. DOI: 10.3724/SP.J.1140.2014.02001

南海北部白云凹陷陆坡海底峡谷地形地貌与沉积地层特征

CANYON MORPHOLOGY AND SEDIMENTS ON NORTHERN SLOPE OF THE BAIYUN SAG

  • 摘要: 利用2011年在南海白云凹陷北部陆坡海域获得的多波束测深数据和浅层多道地震剖面,对研究区海底峡谷的地形地貌要素和沉积地层进行了详细的分析。在水深500~1 700 m范围内识别出14条NNW-SSE向或近N-S向展布的近直线型海底峡谷,长度为12~39.2 km,宽度为1.1~3.4 km,下切深度最大达234 m,谷壁西缓东陡,谷底最深处均靠近东侧谷壁。峡谷上段谷底无沉积物堆积或有少量蚀余堆积,地层反射面略向东倾斜,谷壁上有滑塌现象。下段谷底位于浊流堆积扇上,沉积厚度较大,地层呈平行或亚平行的反射模式,侧向连续性好,有些地方发育密集的断层和滑塌构造。谷脊布满了丘状凸起,地层结构揭示出其沿坡爬升的趋势,有的凸起下方有沿断层向谷底方向的错动。

     

    Abstract: Detail interpretation of morphology and stratigraphic structure was made in this paper for the bottom deposits in the Baiyun Sag, based on the multi-beam bathymetric data and multi-channel seismic profiles. We recognized 14 submarine canyons of 12~39.2 km long and 1.1~3.4 km wide distributed in NNW-SSE or nearly N-S directions in the water depth of 500~1 700 m. The maximum incision is up to 234m in depth. The eastern wall of the canyons is usually steeper than the western and the deepest part of the canyon is close to the eastern wall. There is none or only a small amount of sediments occurred in the upper segments of the canyons and the surface of sediments, if any, tilted slightly eastward. However, the lower segments of canyons usually occur upon turbidite fans with parallel or sub-parallel reflection. Faults and slumping structures are densely developed in some places. Convex structures are commonly observed on canyon ridges and the internal structure of the deposits indicates a climbing up trend along slope.

     

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