PLANKTONIC FORAMINIFERA - SELECTIVE SOLUTION AND LYSOCLINE
PLANKTONIC FORAMINIFERA - SELECTIVE SOLUTION AND LYSOCLINE
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DOI：
10.1016/0025-3227(70)90001-0
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发表时间：
1970-01-01
期刊：
影响因子：
2.9
通讯作者：
BERGER, WH
中科院分区：
文献类型：
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作者：
BERGER, WH
太平洋沃茨除了最上层几百米以外，在所有深度都是碳酸钙不饱和的。这导致暴露在太平洋洋底的几乎所有钙质沉积物不断遭到破坏。从沉积物和浮游生物中提取的样品在太平洋中部的一个拉紧线浮标上暴露了四个月，以评估溶液对有孔虫死亡组合的影响。不同物种和物种内不同变异体的破坏率各不相同。因此，沉积物组合应趋向于富含抗性（无刺）物种和不透明（通常为厚壳）、零和负形式，即，具有小终室的标本。室内实验结果与野外溶解实验结果相吻合，东太平洋海隆表层沉积物中的阻力形态分布表明，该地区存在一个溶解快速增长（溶跃层）的水平。溶跃层的表面位于东太平洋海隆西侧的热带地区，深度约为4，000米。溶跃层表面向南极洲和南美洲方向向上倾斜，在高纬度地区和靠近大陆的地方明显变得不那么清晰。碳酸钙补偿深度是由溶解速率和石灰质供应速率的平衡引起的，通常远低于溶跃层。溶跃层的存在意味着一个相关的氧气最小屋顶，并绑定到两个活跃的底层水生产和过剩的方解石供应的浮游生物。
Pacific Ocean waters appear to be undersaturated with calcium carbonate at all depths except in the uppermost few hundred meters. This leads to continuous destruction of almost all calcareous sediment exposed on the Pacific Ocean floor. Samples derived from sediment and from plankton were exposed for four months on a taut wire buoy in the central Pacific, in order to assess the effects of solution on foraminiferal death assemblages. The rate of destruction varied for different species and for different variants within species. Sediment assemblages therefore should tend to become enriched with resistant (non-spinose) species and with opaque (usually thick-shelled), zero and negative forms, i.e., specimens with small terminal chambers. Results obtained by laboratory experiments compare well with those obtained from the solution experiments in the field.The distribution of resistant forms in surface sediment samples from the East Pacific Rise shows that there exists a level of rapid solution increase (lysocline) in this area. The surface of the lysocline is at approximately 4,000 m depth in the tropics on the western side of the East Pacific Rise. The lysocline surface slopes upward toward Antarctica and toward South America and apparently becomes less well defined in high latitudes and near the continent. The calcium carbonate compensation depth results from a balance of rates of solution and of rates of supply of calcareous matter and usually lies well below the lysocline. The existence of a lysocline implies an associated oxygen minimum roof, and is bound to both active bottom water production and excess calcite supply by planktonic organisms.