Stable isotope of some selected Egyptian pectinids and their paleoenvironmental implications

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• 作者：Soheir H. El-Shazly<sup> ; sup><sup>asup><sup> ; sup><sup>soheir14@gmail.comsup>
• 关键词：Stable isotope ; Paleoenvironment ; Miocene ; Plio-Pleistocene ; Recent ; Pectinids ; Egypt
• 刊名：Journal of African Earth Sciences
• 出版年：2011
• 出版时间：February 2011
• 年：2011
• 卷：59
• 期：2-3
• 页码：283-294
• 全文大小：2290 K

文摘

Eight pectinid shells were collected and subjected to quantitative study using δ<sup>18sup>O and δ<sup>13sup>C isotopic analysis in order to study the paleoenvironment which prevailed during their calcification. The scalerochronological variations in δ<sup>18sup>O and δ<sup>13sup>C values, among these shells are also discussed. The Early Miocene pectinid shells display highly depleted δ<sup>18sup>O and δ<sup>13sup>C signature as a result of paleo-meteoric water with heavy rainfall that was produced by Tropical Cyclones when the Mediterranean Sea was open. The Early Pliocene pectinid shells reveal depleted δ<sup>18sup>O values, related to the influx of fresh water influenced by monsoonal activity following the formation of the Tibetan Plateau. Their enrichment in the δ<sup>13sup>C isotopic excursion is referred to high productivity of the Indian Ocean, which was the main source of the Red Sea water. The Pleistocene pectinid shell shows highly depleted δ<sup>18sup>O and δ<sup>13sup>C signature with obvious diagenetic shell structure, indicating that a wetter humid climate prevailed during the Early–Middle Pleistocene and long sub-arial exposure of the shell. The Recent Mediterranean pectinid shell displays slight enrichment in δ<sup>18sup>O and δ<sup>13sup>C values referring to deeper inhabitation of this species with a low temperature and high salinity environment. The scalerochronological variations in both δ<sup>18sup>O and δ<sup>13sup>C values, along these shells is referred to seasonal variations or kinetic effects.