Geometry and development of glacial continental margin depositional systems in the Bellingshausen Sea
Geometry and development of glacial continental margin depositional systems in the Bellingshausen Sea
复制标题
别林斯高晋海冰川大陆边缘沉积系统的几何结构和发育
DOI：
10.1016/s0025-3227(99)00074-2
复制
发表时间：
2000
期刊：
影响因子：
2.9
通讯作者：
K. Gohl
中科院分区：
文献类型：
--
作者：
F. Nitsche;A. Cunningham;R. Larter;K. Gohl
我们提出了多通道地震（MCS）反射剖面和测深数据采集在一个偏远的和调查不足的部分南极大陆边缘的别林斯高晋海和阿蒙森海。这些新资料已与公布的数据结合起来，用于解释大陆架、陆坡和海隆的沉积类型，并描述该区域活跃的沉积过程。大多数穿越大陆边缘的地震反射剖面显示外陆架和上斜坡下的沉积序列，我们推断，这些序列的地层特征表明，接地冰盖达到陆架边缘在以前的冰期。虽然有一般的相似之处，在这些配置文件的地层几何形状，在细节上，他们揭示了显着的纵向变化，沉积物输入从货架上斜坡。在几个剖面上，我们发现了以滑塌和泥石流沉积物形式存在的大陆坡质量损耗的证据。在更深的深度，浊流、底流和科氏力控制着沉积物的进一步搬运和沉积，导致土丘、水道和沉积物波场的发展。土丘的分布以及大小和几何形状的变化反映了沉积物的输入以及控制大陆隆起沉积作用的其他因素的相对贡献。
We present multi-channel seismic (MCS) reflection profiles and bathymetry data acquired across a remote and poorly surveyed part of the Antarctic continental margin in the Bellingshausen and Amundsen Seas. This new information has been combined with published data and used to interpret the style of sedimentation on the continental shelf, slope and rise, and to describe sedimentation processes which have been active in this region. Most seismic reflection profiles crossing the continental margin show prograded sequences beneath the outer shelf and upper slope, and we infer that the stratal characteristics of these sequences indicate that grounded ice sheets reached the shelf edge during previous glacial times. Although there are general similarities in stratal geometry on these profiles, in detail, they reveal significant longitudinal variations in sediment input from the shelf to the upper slope. On several profiles, we found evidence of mass wasting of the continental slope in the form of slump and debris flow deposits. At greater depth, turbidity flows, bottom currents and Coriolis force have controlled the further transportation and deposition of sediment, which has resulted in the development of mounds, channels and sediment wave fields. The distribution, and variations in the size and geometry of the mounds reflect sediment input and the relative contribution of these other factors which control sedimentation on the continental rise.