Plate reorganization: a cause of rapid late Neogene subsidence and sedimentation around the North Atlantic?
Plate reorganization: a cause of rapid late Neogene subsidence and sedimentation around the North Atlantic?
复制标题
板块重组：北大西洋周围新近纪晚期快速沉降和沉积的原因？
DOI：
10.1144/gsjgs.147.3.0495
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发表时间：
1990
影响因子：
2.7
通讯作者：
Michael A. Kaminski
中科院分区：
文献类型：
--
作者：
S. Cloetingh;F. Gradstein;F. Gradstein;Henk Kooi;A. C. Grant;Michael A. Kaminski
对北海中部和拉布拉多大浅滩以及西格陵兰岛、斯科舍大陆架和美国大西洋边缘的井的沉降分析显示了环北大西洋地区独特的定量地层相关模式。当发现沉降速率较渐新世/中新世速率增加一个或多个数量级时，许多井都出现了与上新世沉降总体减少的显着背离。沿着从海岸到盆地的横断面选择井，以查明相对盆地位置是否受到盆地沉降差异的影响。尽管地层分辨率不详细，但更多盆地地点在新近纪晚期经历的沉降率比渐新世/中新世高出四倍，并在上新世达到峰值。盆地边缘的井经历的沉降要少得多，或者表现出隆起。这些观察结果与新近纪沉降中观察到的转变的原因是板内应力的快速变化一致。上新世期间，整个大西洋扩张系统发生了扩张方向和速率的重大重组，可能与板块运动的全球变化有关。我们认为板内应力的相关变化导致了超额下沉。沿盆地边缘的相对抬升与这种相对运动机制一致，并且可以解释海平面明显的海平面变化。
Subsidence analysis of wells in the central North Sea and Labrador-Grand Banks and oft the West Greenland, Scotian shelf and United States Atlantic margin shows distinct quantitative stratigraphic correlation patterns of circum North Atlantic sites. A significant departure from the overall decrease in subsidence for the Pliocene occurs in many wells, when the rate is found to have increased one or more orders of magnitude from Oligocence/Miocene rates. Wells were selected along transects from shore to basin to find if relative basin position is influenced by differential basin subsidence. Although stratigraphic resolution is not detailed, more basinward sites experienced up to four times larger subsidence rates in the late Neogene than in the Oligocene/Miocene, with a peak in the Pliocene. Wells at the basin edge experienced much less subsidence or showed uplift. The observations are consistent with a rapid change of intraplate stress at the cause for this observed transition in Neogene subsidence. Major reorganizations of spreading direction and rate occurred during the Pliocene along the entire Atlantic spreading system, possibly in conjunction with more global changes in plate motions. We propose that the associated changes in intraplate stress caused the excess margin subsidence. Relative uplift along basin edges is consistent with this mechanism of relative movement and may explain apparent eustatic changes in sea level.