Paleoenvironmental implications of Cenozoic sediments from the central Arctic Ocean (IODP Expedition 302) using inorganic geochemistry
Paleoenvironmental implications of Cenozoic sediments from the central Arctic Ocean (IODP Expedition 302) using inorganic geochemistry
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利用无机地球化学研究北冰洋中部新生代沉积物（IODP Expedition 302）的古环境影响
DOI：
10.1029/2009pa001860
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Brumsack H-J
中科院分区：
文献类型：
--
作者：
März C;Schnetger B;Brumsack H-J
综合大洋钻探计划（IODP）第302次考察（Arctic Coring Expedition，ACEX）在北冰洋中部发现了一个独特的沉积物记录，揭示了该地区自晚白垩世以来经历了重大的环境波动。使用X射线荧光（XRF）测定了1，300个样品的主量和微量元素组成。结果表明，沉积物的组成随深度的变化，可以归因于（a）碎屑物质的来源和途径，（B）古环境条件和沉积过程，和（c）成岩叠加的原始记录的变化。除了现有的岩性单位，我们引入了新的地球化学单位，用于解释ACEX记录的更与过程相关的方法。详细地说，通过西伯利亚洪水玄武岩的地球化学特征，我们能够重建不连续的裂谷和加深的中央罗蒙诺索夫海岭在古近纪，伴随着不断变化的电流制度和海冰的发病。始新世生物硅质沉积发生在相对较浅的环境中，主要是缺氧的底层水条件下，导致积极的缺氧-生产力反馈，虽然水柱分层反复中断通风事件。在生物硅生产停止后，缺氧到硫化物的条件更加极端，大量的黄铁矿沉积在罗蒙诺索夫海岭。特别是在富含有机质的古近纪沉积物中，成岩过程掩盖了古环境信号。始新世中期发生了基本的环境变化，但地球化学和微体古生物学代理点不相同的沉积深度。在大约26 Ma的非沉积或侵蚀之后，中中新世记录显示过渡到主要是氧化性的底层水条件，尽管亚氧化成岩作用似乎影响了这些沉积物。
Integrated Ocean Drilling Program (IODP) Expedition 302 (Arctic Coring Expedition, ACEX) recovered a unique sediment record from the central Arctic Ocean, revealing that this region underwent major environmental fluctuations since the Late Cretaceous. Major and trace element composition of 1,300 samples were determined using X‐ray fluorescence (XRF). The results show significant compositional variability of the sediments with depth that can be attributed to changes in (a) provenance and pathways of detrital material, (b) paleoenvironmental conditions and depositional processes, and (c) diagenetic overprint of the primary record. In addition to existing lithological units, we introduce new geochemical units for a more process‐related approach interpreting the ACEX record. In detail, via the geochemical signature of Siberian flood basalts we are able to reconstruct the discontinuous rifting and deepening of the central Lomonosov Ridge during the Paleogene, accompanied by changing current regimes and the onset of sea ice. Eocene biosiliceous sedimentation took place in a relatively shallow setting under predominantly anoxic bottom water conditions, causing a positive anoxia‐productivity feedback, although water column stratification was repeatedly interrupted by ventilation events. Anoxic to sulfidic conditions were even more extreme after biosilica production ceased, and significant amounts of pyrite were deposited on the Lomonosov Ridge. Especially in organic matter‐rich Paleogene deposits, diagenetic processes obscured the paleoenvironmental signals. Fundamental environmental changes occurred in the Middle Eocene, but geochemical and micropaleontological proxies point not to the identical sediment depth. After approximately 26 Ma of non‐deposition or erosion, the Middle Miocene record shows the transition to dominantly oxic bottom water conditions, although suboxic diagenesis seemingly affected these deposits.
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影响因子：
--
作者：
P. Weller;R. Stein
通讯作者：
P. Weller;R. Stein
波罗的海全新世淡水-咸水转变过程中缺氧的发展
影响因子：
2.9
作者：
G. Sohlenius;K. Emeis;E. Andrén;T. Andrén;A. Kohly
通讯作者：
A. Kohly
北冰洋中部新生代陆源沉积物来源判别
影响因子：
--
作者：
N. Martinez;R. Murray;G. Dickens;M. Kölling
通讯作者：
M. Kölling
从罗蒙诺索夫海岭鱼类残骸化石中的 Nd-Sr 同位素了解北冰洋早至中期始新世历史
影响因子：
--
作者：
J. Gleason;D. J. Thomas;T. C. Moore;J. Blum;R. M. Owen;B. Haley
通讯作者：
B. Haley
第 7 章 海洋重晶石
DOI：
--
发表时间：
1979
期刊：
影响因子：
--
作者：
T. Church
通讯作者：
T. Church