Submarine valleys on the Ceduna Terrace off South Australia

A detailed bathymetric map has been compiled for the Ceduna Terrace, off South Australia. The most striking features of the bathymetry are numerous submarine valleys, which dissect the otherwise gently sloping terrace. These are mostly broad and shallow, and form a dendritic tributary system feeding submarine canyons on the lower slope. The valleys were probably eroded by turbidity currents generated near the shelf-break during low sea-level stands. There is little evidence to suggest that they have resulted from mass movement and slumping or from subaerial erosion. Most valleys appear to have developed during the Quaternary, but some may have originated in the Tertiary.

针对澳大利亚南部近海的塞杜纳海底阶地（Ceduna Terrace），已编制完成一份详细的海底测深图（bathymetric map）。该海底地形（bathymetry）最显著的特征为发育大量海底谷（submarine valley），它们切割了原本平缓倾斜的海底阶地。这些海底谷大多宽浅，形成树枝状支谷系统，汇入陆坡下部的海底峡谷。此类海底谷大概率是在低海平面时期，由陆架坡折（shelf-break）附近产生的浊流（turbidity current）侵蚀形成。目前几乎没有证据表明它们是由块体运动（mass movement）、滑塌（slumping）或陆上侵蚀（subaerial erosion）作用所导致。多数海底谷似乎形成于第四纪（Quaternary），但部分可能起源于第三纪（Tertiary）。