Metamorphic temperature investigation of coexisting calcite and dolomite marble––examples from Nikani Ghar marble and Nowshera Formation, Peshawar Basin, Pakistan

详细信息    查看全文

• 作者：Muhammad Fahad ; Yaseen Iqbal ; Mohammad Riaz ; Rick Ubic…
• 关键词：Key wordscalcite ; dolomite ; metamorphic temperature ; geothermometer ; X ; ray diffraction
• 刊名：Journal of Earth Science
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：27
• 期：6
• 页码：989-997
• 全文大小：2169KB
• 刊物主题：Earth Sciences, general; Geotechnical Engineering & Applied Earth Sciences; Biogeosciences; Geochemistry; Geology;
• 出版者：China University of Geosciences
• ISSN：1867-111X
• 卷排序：27

文摘

Using marble samples from the Nikani Ghar marble and Nowshera Formation from Northern Pakistan the determination of the temperature of metamorphism was undertaken with the help of calcite-dolomite solvus geothermometer. Two types of marbles, that is, calcite-dolomite marble and quartz-bearing calcite-dolomite marble were selected. Petrographic and scanning electron microscope analysis of dolomite samples indicated different grain sizes. X-ray diffraction technique indicated the calcites MgCO₃ content up to 7.93 mol.%. Nikani Ghar marble samples have shown lower contents of MgCO₃ as compared to samples from Nowshera Formation. The calcite-dolomite-quartz marble has also showed relatively lower MgCO₃ content and hence rather low temperature (~500 °C). The temperature reached during peak metamorphism of the investigated marble occurrence, based on calcitedolomite solvus was 628 °C. Metamorphic temperatures derived from the present study were shown as a linear graph and values were in good agreement with the published literature.