A synthesis of Cenozoic sedimentation in the North Sea
A synthesis of Cenozoic sedimentation in the North Sea
复制标题
北海新生代沉积综合
DOI：
10.1111/j.1365-2117.2011.00517.x
复制
发表时间：
2012
期刊：
影响因子：
3.2
通讯作者：
E. Rasmussen
中科院分区：
文献类型：
--
作者：
I. Anell;H. Thybo;E. Rasmussen
北海盆地包含几乎完整的新生代沉积记录，由明显的区域不整合面隔开。沉积物特征、速率和来源的变化以及不整合面的表现反映了北海及其边缘所经历的构造、海平面上升和气候变化。虽然北海已经在当地绘制了地图，但我们提出了新生代沉积地层的第一个区域地图。我们的研究提供了北海主要地震单元的新区域细分以及震源、流入方向和震源区地图。我们的研究基于对覆盖区域的反射地震数据集的综合解释，提供了沉积作用的区域综合。我们将沉积物特征和不整合面的观察与地质演化联系起来。许多不整合面的时间、区域表现和地层特征表明，它们是由海平面上升下降产生的，通常与其他过程结合在一起。然而，新生代早期的不整合面与北大西洋开口的构造运动有关。通过对区域尺度的观察，我们推断，新生代沉积物流入北海的情况比之前提出的从西北早期到南部晚期的顺时针旋转更为复杂。设得兰台地持续不断地提供沉积物，尽管速度不同，直到新生代末期。挪威周围的沉积作用从新生代早期从西南边缘涌入，转变为渐新世几乎完全来自南缘以及新生代末期整个挪威南部。中地堑中厚厚的始新世沉积物主要来自西部和可能的南部来源，这表明来自南部的大量涌入不仅发生在中新世中期以后。我们推断更新世 2.5 Ma 沉积物流入增加的新时代，与芬诺斯坎迪亚冰川作用同时期。
The North Sea Basin contains an almost complete record of Cenozoic sedimentation, separated by clear regional unconformities. The changes in sediment characteristics, rate and source, and expression of the unconformities reflect the tectonic, eustatic and climatic changes that the North Sea and its margins have undergone. While the North Sea has been mapped locally, we present the first regional mapping of the Cenozoic sedimentary strata. Our study provides a new regional sub‐division of the main seismic units in the North Sea together with maps of depocentres, influx direction and source areas. Our study provides a regional synthesis of sedimentation based on a comprehensive interpretation of a regionally covering reflection seismic data set. We relate observations of sediment characteristics and unconformities to the geological evolution. The timing, regional expression and stratigraphic characteristics of many unconformities indicate that they were generated by eustatic sea‐level fall, often in conjunction with other processes. Early Cenozoic unconformities, however, relate to tectonism associated with the opening of the North Atlantic. From observation on a regional scale, we infer that the sediment influx into the North Sea during the Cenozoic is more complex than previously suggested clockwise rotation from early northwestern to late southern sources. The Shetland Platform supplied sediment continuously, although at varying rates, until the latest Cenozoic. Sedimentation around Norway changed from early Cenozoic influx from the southwestern margin, to almost exclusively from the southern margin in the Oligocene and from all of southern Norway in the latest Cenozoic. Thick Eocene deposits in the Central Graben are sourced mainly from a western and a likely southern source, indicating that prominent influx from the south did not only occur from the mid‐Miocene onwards. We infer a new age for the increased progradational sediment influx in the Pleistocene of 2.5 Ma, coeval with Fennoscandian glaciation.