BIOMARKER EVIDENCE FOR HEINRICH EVENTS
BIOMARKER EVIDENCE FOR HEINRICH EVENTS
复制标题
海因里希事件的生物标记证据
DOI：
10.1016/s0016-7037(97)00046-x
复制
发表时间：
1997
影响因子：
5
通讯作者：
P. Schaeffer
中科院分区：
文献类型：
--
作者：
A. Rosell‐Melé;M. Maslin;J. Maxwell;P. Schaeffer
在北大西洋沉积物中发现的所谓海因里希层被认为是来自劳伦蒂德冰盖的冰山舰队准周期性排放的结果。利用生物标志物在沉积物芯（BOFS 5K）的分布，我们试图提供更多的信息，它们的起源和影响的海因里希事件对海洋环流和气候系统。通过U37K测量对海洋表面温度变化的估计表明，在这些事件中，海洋表面经历了显着的冷却，这可能是由于冰山融水的流入。海水温度低和叶绿素衍生色素积累的迅速变化表明，这些事件引起了海洋条件的重大变化，这可能影响了大西洋的温盐环流。在最近的层中，我们还发现了钒烷基卟啉和芳基类异戊二烯烃，光合色素（叶绿素和类胡萝卜素，分别）的成岩产物。这些成分预计不会出现在晚第四纪沉积物中，因此它们的存在证明了对大陆起源的古老、富含有机物的沉积物层的贡献。钒卟啉的存在和它们的镍对应物的缺乏，以及芳基类异戊二烯的分布特征（例如，绿色硫细菌来源的C40还原类胡萝卜素异戊烯烷的存在）表明在贡献的古沉积物的原始沉积环境中海洋水柱的透光带中存在缺氧条件。这些结果表明，它应该是可能的，使用生物标志物相关的方法，以确定由冰山侵蚀的古代沉积物的源区。
The so-called Heinrich layers, found in North Atlantic sediments, have been attributed to quasi-periodic discharges of armadas of icebergs originating from the Laurentide ice sheet. Using the distribution of biomarkers in a sediment core (BOFS 5K) we have attempted to provide more information about their origin and the effect of the Heinrich events on oceanic circulation and the climatic system. Estimates of sea surface temperature changes, via U37Kmeasurements, show that the surface ocean underwent significant cooling during the events, probably as a result of incoming iceberg meltwater. The low sea temperatures and the rapid variation in the accumulation of chlorophyll-derived pigments suggest that the events provoked a major change in oceanographic conditions, which may have affected the thermohaline circulation in the Atlantic Ocean. Within the most recent layers we have also found vanadyl alkyl porphyrins and aryl isoprenoid hydrocarbons, diagenetic products of photosynthetic pigments (chlorophylls and carotenoids, respectively). These components are not expected to occur in late Quaternary sediments, so their presence demonstrates a contribution to the layers of ancient, organic rich sedimentary material of continental origin. The presence of vanadyl porphyrins and absence of their nickel counterparts, and the distributional features of the aryl isoprenoids (e.g., presence of the C40reduced carotenoid isorenieratane of green sulphur bacterial origin) indicate the existence of anoxic conditions in the photic zone of a marine water column in the original depositional setting of the contributed ancient sediment. These results suggest that it should be possible, using a biomarker correlation approach, to determine the source area of the ancient sediment eroded by the icebergs.