Effects of diagenesis on the isotopic record of late paleogene tropical sea surface temperatures
Effects of diagenesis on the isotopic record of late paleogene tropical sea surface temperatures
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DOI：
10.1016/s0009-2541(99)00088-1
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发表时间：
1999-09-30
期刊：
影响因子：
3.9
通讯作者：
Schrag, DP
中科院分区：
文献类型：
--
作者：
Schrag, DP
浮游有孔虫的氧同位素记录表明，在高纬度海面温度高于现代的情况下，晚始新世和渐新世热带海面温度比现在低8摄氏度。利用描述深海碳酸盐埋藏和重结晶过程中氧同位素交换的数值模型，量化了4个热带地点成岩作用对新生代整体碳酸盐三角洲(18)O记录的影响。在所有地点观测到的三角洲(18)O值的大部分变化都可以用成岩作用来解释。除了成岩作用以外，没有系统的趋势支持热带海洋表面温度的实质性变化，可能的例外是始新世早期，其数据与略高的海洋表面温度相一致。根据浮游有孔虫的氧同位素记录进行的重建表明始新世和渐新世热带海面温度较低，这可能是成岩重结晶的产物，因为这种记录对成岩作用特别敏感。(C)1999 Elsevier Science B.V.保留所有权利。
Oxygen isotope records of planktonic foraminifera indicate that Late Eocene and Oligocene tropical sea surface temperatures were as much as 8 degrees C lower than present at a time when high latitude sea surface temperatures were higher than present. Using a numerical model which describes oxygen isotope exchange during burial and recrystallization of deep sea carbonate, the effects of diagenesis on bulk carbonate delta(18)O records for the Cenozoic are quantified for four tropical sites. Most of the observed variations in measured delta(18)O values at all sites can be accounted for by diagenetic effects. There are no systematic trends that support substantial variations in tropical sea surface temperatures beyond diagenetic effects, with the possible exception of the Early Eocene for which the data are consistent with slightly higher sea surface temperatures. Reconstructions based on oxygen isotope records of planktonic foraminifera which indicate cooler tropical sea surface temperatures for the Eocene and Oligocene may be artifacts of diagenetic recrystallization as such records are particularly sensitive to diagenetic effects. (C) 1999 Elsevier Science B.V. All rights reserved.