Quaternary sedimentation, margin architecture and ocean circulation variability around the Faroe Islands, North Atlantic
Quaternary sedimentation, margin architecture and ocean circulation variability around the Faroe Islands, North Atlantic
复制标题
北大西洋法罗群岛周围的第四纪沉积、边缘结构和海洋环流变化
DOI：
10.1016/j.quascirev.2006.12.005
复制
发表时间：
2007
影响因子：
4
通讯作者：
A. Kuijpers
中科院分区：
文献类型：
--
作者：
T. Nielsen;T. L. Rasmussen;S. Ceramicola;A. Kuijpers
利用DANA 2000号考察船和以往考察船的高分辨率地震和岩心数据，研究了法罗群岛近海的第四纪发展。几个冰川相关的功能和存款观察，都见证了法罗地区以前广泛的冰川。在大陆架上，覆盖在中更新世冰川侵蚀表面上，冰川和冰川沉积物形成了一个被沉积物脊打断的片状几何形状，这些沉积物脊可能代表冰前沉积物。法罗群岛北部的一个冰山扰动提供了在前韦克塞尔冰期北欧海超深吃水（> 600米）冰山大规模漂移的证据。在东部和西部大陆架上发现的边缘和横向槽被认为是在与冰山扰动相同的冰期形成的。冰山犁痕和丰富的冰筏材料的非法罗群岛的起源，连同残余的冰碛脊环绕法罗群岛周围的100和200米水深的轮廓，表明外大陆架可能是冰免费的Weichselian冰期。在斜坡和盆地的部分，形成细粒等深岩有利于（Weichselian）冰期时，底部电流减少。在这些冰川阶段的沉积物超载导致反复的斜坡不稳定，造成等深流沉积物的质量故障。
The Quaternary development offshore the Faroe Islands has been studied using high-resolution seismic and core data from the R/V DANA 2000 cruise and previous cruises. Several glacial-related features and deposits are observed, all bearing witness to former extensive glaciations of the Faroe area. On the shelves, overlaying a mid-Pleistocene glacial erosional surface, glacial and glacimarine deposits form a sheet geometry interrupted by ridges of sediment that are likely to represent ice-front deposits. An iceberg turbate north of the Faroe Islands provides evidence of large-scale drift of ultra-deep draft (>600m) icebergs in the Nordic Seas at pre-Weichselian glacial stage(s). Marginal and transverse troughs found on the eastern and western shelf are suggested to have formed during the same glacial period(s) as the iceberg turbate. Iceberg plough-marks and abundant ice rafted material of non-Faroese origin, together with the relict moraine ridges encircling the Faroe Islands at around the 100 and 200m water depth contours, indicate that the outer shelf was probably ice free during the Weichselian ice age. On the slopes and basinal parts, the formation of fine-grained contourites was favoured during (Weichselian) glacial stages when bottom currents were reduced. Sediment overloading during these glacial stages resulted in repeated slope instability, causing mass failures of the contourite deposits.