Physical properties of sediment cores from the Arctic Ocean

Sediments of the Arctic Ocean are recorders of oceanographic and climatic evolution in the northern hemisphere, The sedimentary history is reflected in the sediment physical properties, thus knowledge about them is a key to its Interpretation particularly within the Quaternary. In this study, 29 sediment cores from the eastern Arctic Ocean were investigated On porosity, wet bulk density and ten cores on compressional (P-) wave velocity. Analysis of these parameters permits interpretations about the sedimentary conditions in the Amundsen and Makarov Basins and on the Lomonosov Ridge, Yermak Plateau and Morris Jesup Rise. The distribution of 25 sediment cores throughout abyssal hill and abyssal plain locations of the eastern Arctic Ocean show specific distribution patterns of wet bulk densities and porosities which characterize the sedimentary regions. On the Yermak Plateau undisturbed pelagic sedimentation predominates. The Lomonosov Ridge and the Morris Jesup Rise are characterized by winnowing. On the Gakkel Ridge turbidite and ice transported deposits are dominant. With the exception of turbidite layers in the Amundsen Basin and ice transported sandy layers in the Makarov Basin, sediments of these basins are dominated by fine-grained sediment. ff...北冰洋沉积物是北半球海洋学与气候演化的天然记录载体。沉积历史蕴含于沉积物的物理性质之中，因此对这些物理性质的研究，是解读其沉积记录的关键，尤其针对第四纪（Quaternary）时期。本研究针对北冰洋东部海域的29个沉积物岩心（sediment cores）开展了孔隙度（porosity）与湿体密度（wet bulk density）的测试分析，并对其中10个岩心测定了纵波（P波）速度。通过对上述参数的解析，可对阿蒙森海盆（Amundsen Basin）、马卡罗夫海盆（Makarov Basin）、罗蒙诺索夫海岭（Lomonosov Ridge）、叶尔马克高原（Yermak Plateau）以及莫里斯·杰瑟普海隆（Morris Jesup Rise）的沉积环境进行解译。本次研究在北冰洋东部的深海丘陵（abyssal hill）与深海平原（abyssal plain）区域采集的25个沉积物岩心数据显示，湿体密度与孔隙度呈现出具有区域特征的分布模式。叶尔马克高原以未受扰动的远洋沉积（pelagic sedimentation）为主；罗蒙诺索夫海岭与莫里斯·杰瑟普海隆以淘洗作用（winnowing）为典型特征；加克洋中脊（Gakkel Ridge）则以浊流沉积（turbidite）与冰运沉积物（ice transported deposits）为主。除阿蒙森海盆内的浊流层以及马卡罗夫海盆内的冰运砂质层外，上述两个海盆的沉积物均以细粒沉积物（fine-grained sediment）为主。