Glaciomarine sedimentation and bottom current activity on the north-western and northern continental margins of Svalbard during the late Quaternary
Glaciomarine sedimentation and bottom current activity on the north-western and northern continental margins of Svalbard during the late Quaternary
复制标题
晚第四纪斯瓦尔巴群岛西北和北部大陆边缘的冰川沉积和底流活动
作者：
Teena Chauhan;R. Noormets;T. L. Rasmussen
西斯匹次卑尔根海流（WSC）的古底流强度和斯瓦尔巴-巴伦支海冰盖（SBIS）对斯瓦尔巴北方边缘沿着沉积环境的影响知之甚少。研究了叶尔马克高原南部和东北地区北部上坡的两个重力岩心，涵盖海洋同位素阶段（MIS）1至MIS 5。根据粒度分布、粉/粘比值、可分选粉砂含量和平均值等特征，划分了5种岩相，以确定等深流沉积环境。此外，沉积环境的总有机碳（TOC），总硫（TS）和碳酸钙（CaCO 3）含量的沉积物。相A，含有粗SS，表明强烈的底流活动和良好的底层水通风条件推断，从低TOC含量。该相沉积于冰川期MIS 4、MIS 2和全新世晚期。B相以细SS为主，表明底流较弱，通风较差（参见高TOC含量（1.2-1.6%），并与MIS 4/3和MIS 2/1过渡期相关。具有等量的粘土和砂、细SS和高含量的TOC，C相指示具有来自近源（例如冰山、海冰或融水排放）的沉积物供应的间隔的底流强度降低。该相沉积于末次盛冰期。D相代表斯瓦尔巴群岛北方边缘的物质流沉积，这归因于SBIS在陆架边缘或其附近的推进。相E沉积物表明中等底流强度沉积在MIS 5和MIS 3，并在部分MIS 2。这第一晚第四纪代理记录的WSC流量和沉积历史的北方斯瓦尔巴群岛边缘表明，海洋条件和冰盖过程施加了一阶控制沉积物的性质。
Palaeo-bottom current strength of the West Spitsbergen Current (WSC) and the influence of the Svalbard-Barents Sea Ice Sheet (SBIS) on the depositional environment along the northern Svalbard margins are poorly known. Two gravity cores from the southern Yermak Plateau and the upper slope north of Nordaustlandet, covering marine isotope stage (MIS) 1 to MIS 5, are investigated. Five lithofacies, based on grain size distribution, silt/clay ratio, content and mean of sortable silt (SS), are distinguished to characterise the contourite-dominated sedimentary environments. In addition, depositional environments are described using total organic carbon (TOC), total sulphur (TS) and calcium carbonate (CaCO3) contents of sediments. Facies A, containing coarse SS, suggests strong bottom current activity and good bottom water ventilation conditions as inferred from low TOC content. This facies was deposited during the glacial periods MIS 4, MIS 2 and during the late Holocene. Facies B is dominated by fine SS indicating weak bottom current and poor ventilation (cf. high TOC content of 1.2–1.6%), and correlates with the MIS 4/3 and MIS 2/1 transition periods. With an equal amount of clay and sand, fine SS and high content of TOC, facies C indicates reduced bottom current strength for intervals with sediment supply from proximal sources such as icebergs, sea ice or meltwater discharge. This facies was deposited during the last glacial maximum. Facies D represents mass-flow deposits on the northern Svalbard margin attributed to the SBIS advance at or near the shelf edge. Facies E sediments indicating moderate bottom current strength were deposited during MIS 5 and MIS 3, and during parts of MIS 2. This first late Quaternary proxy record of the WSC flow and sedimentation history from the northern Svalbard margin suggests that the oceanographic conditions and ice sheet processes have exerted first-order control on sediment properties.
影响因子：
18.3
作者：
Rippeth, Tom P.;Lincoln, Ben J.;Bacon, Sheldon
通讯作者：
Bacon, Sheldon