Gulf Stream: Reconstruction of Cenozoic flow patterns over the Blake Plateau
Gulf Stream: Reconstruction of Cenozoic flow patterns over the Blake Plateau
复制标题
墨西哥湾流：布莱克高原新生代流动模式的重建
DOI：
--
复制
发表时间：
1981
期刊：
影响因子：
--
通讯作者：
David F. Nelligan
中科院分区：
文献类型：
--
作者：
P. Pinet;P. Popenoe;David F. Nelligan
在古新世地层顶部挖掘的凹凸不平的沟渠地貌表明，墨西哥湾流与布莱克高原的相互作用早在古新世晚期-始新世早期就已经发生。最初，墨西哥湾流穿过布莱克高原的西部边缘，现在被佛罗里达-哈特拉斯斜坡覆盖。到始新世早期，洋流向南转移了200公里，切断了布雷克高原中部水深500米以下的水道，并从布雷克支流的北部流出。整个始新世，墨西哥湾流向东北方向穿过中部高原，并在渐新世中期恢复到靠近古新世的位置，穿过高原西缘；此后不久，它又恢复了穿越中部高原的轨迹。自早中新世以来，流轴在穿越布莱克高原中部的东北流向和沿布莱克高原内侧更偏北的流向之间交替。墨西哥湾流位置的变化是在海平面下降期间，一个显著的水深高压--查尔斯顿凸起--使洋流向东和向南偏转的结果。
Rugged and channeled topography excavated on the top of Paleocene strata and buried by lower Eocene deposits indicates that Gulf Stream interaction with the Blake Plateau occurred as early as late Paleocene-early Eocene time. Initially, the Gulf Stream flowed across the western edge of the Blake Plateau in an area now covered by the Florida-Hatteras slope. By early Eocene, the current had shifted 200 km to the south, cutting channels 500 m bathymetrically lower across the central Blake Plateau and exiting just north of the Blake Spur. The Gulf Stream flowed northeastward across the central plateau throughout the Eocene and returned to near its Paleocene position across the western edge of the plateau in the middle Oligocene; shortly thereafter it resumed its former track across the central plateau. Since the early Miocene, the current axis has alternated between a northeasterly flow path across the central Blake Plateau and a more northerly course along the inner Blake Plateau. Shifts in the position of the Gulf Stream are the result of eastward and southward deflection of the current by a prominent bathymetric high, the Charleston Bump, during periods of sea-level lowering.