The oyxgen and hydrogen isotope geochemistry of ocean sediments and shales
The oyxgen and hydrogen isotope geochemistry of ocean sediments and shales
复制标题
海洋沉积物和页岩的氧和氢同位素地球化学
DOI：
10.1016/0016-7037(70)90150-x
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发表时间：
1970
影响因子：
5
通讯作者：
S. Epstein
中科院分区：
文献类型：
--
作者：
S. Savin;S. Epstein
对来自大西洋、太平洋和印度洋的27个海洋岩心样本的无碳酸盐部分进行了氧和氢同位素分析。δ o18值相对于SMOW的变化范围为+11.5 ~ +28.5 permil， δD值相对于SMOW的变化范围为- 5.5% ~ - 8.7%。在化学分析的基础上，将岩心分为两组，铁锰含量在7 - 15wt %之间，铁锰含量在2 - 5wt %之间。根据Goldberg和Griffin（1963,1967）的矿物学分析以及同位素和化学分析，富锰铁的样品似乎具有大量的自生成分，而贫锰铁的样品似乎主要是碎屑。样品碎屑群中粘土矿物的氧同位素组成反映了这些矿物的物源和成因方式。没有证据表明这些样品与海水之间存在氧同位素交换，也没有确凿的证据表明这些样品与海水之间存在氢同位素交换，尽管用离子-钍法测定了其中一些样品的年龄为25万年（Goldberg and Griffin, 1963）。已公布的页岩δ o18值范围，加上两项新的分析，与碎屑来源的海洋岩心样品的δ o18值范围相似。因此，就同位素记录而言，不可能区分海相和非海相页岩。物质平衡计算表明，在地球历史上，风化和沉积过程的影响是使水圈中的o18减少了约3permil，而使水圈中的氘增加了约0.03%。
Oxygen and hydrogen isotope analyses were made on the carbonate-free fractions of twenty-seven ocean core samples from the Atlantic, Pacific, and Indian Oceans.δO18values ranged from +11.5 to +28.5 permil, and δD values ranged from −5.5 to −8.7 per cent relative to SMOW.On the basis of chemical analyses the cores were divided into two groups, those with Fe + Mn between 7 and 15 wt. % and those with Fe + Mn between 2 and 5 wt. %. On the basis of mineralogic analyses by Goldberg and Griffin (1963, 1967) and isotopic and chemical analyses, the ferromanganese-rich samples appear to have a large authigenic component while the ferromanganese-poor samples appear to be primarily detrital. The oxygen isotopic compositions of the clay minerals in the detrital group of samples reflect the provenance and mode of origin of these minerals. There is no evidence for oxygen isotopic exchange, and inconclusive evidence for hydrogen isotopic exchange between these samples and sea water, even though some have been dated by the ionium-thorium method as being as old as 250,000 years (Goldberg and Griffin, 1963).The range of publishedδO18values of shales, supplemented by two new analyses, is similar to that of the ocean core samples of detrital origin. Therefore, as far as the isotopic record is concerned it is impossible to distinguish between marine and non-marine shales.Material balance calculations suggest that the effect of weathering and sedimentary processes has been to deplete the hydrosphere of O18by about 3 permil and to enrich the hydrosphere in deuterium by about 0.03 per cent during the earth's history.