Scholarlink

Abstract <p>The present work aims to study the phase relations along the CaСO<sub>3</sub>–CaF<sub>2</sub> join at 6 GPa. The experiments were performed using a multianvil press in graphite capsules. The system has one intermediate compound, Ca<sub>2</sub>CO<sub>3</sub>F<sub>2</sub>, identified as brenkite by Raman spectroscopy. At 900–1000°C, the presence of brenkite splits the system into two partial binaries: aragonite + brenkite and brenkite + fluorite. An aragonite-brenkite eutectic is situated near 1080°C. An eutectic melt contains 40 mol% CaF<sub>2</sub>. Brenkite melts incongruently at 1100°C, producing fluorite and peritectic liquid containing 48 mol% CaF<sub>2</sub>. The presence of fluorine lowers the melting temperature of the calcium carbonate by almost 600°C to a temperature corresponding to a continental geotherm with a surface heat flow of 35 mW/m<sup>2</sup>. Thus, under mantle conditions, fluorine enable a calcium carbonate-rich melt to remain liquid at a much lower temperature (1080°C) than would be possible without the presence of fluorine (1660°C).</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

The CaCO3–CaF2 Binary at 6 GPa

  • 期刊论文

  • 发表日期：

    2025年12月1日

查看全文
  • A. Shatskiy,
  • A. V. Kovalenko,
  • Yu. G. Vinogradova,
  • D. V. Shatskaya,
  • K. M. Stepanov,
  • A. S. Shevchuk,
  • G. N. Ovsyannikov,
  • D. E. Sidko,
  • M. A. Nikitin

摘要

Abstract

The present work aims to study the phase relations along the CaСO3–CaF2 join at 6 GPa. The experiments were performed using a multianvil press in graphite capsules. The system has one intermediate compound, Ca2CO3F2, identified as brenkite by Raman spectroscopy. At 900–1000°C, the presence of brenkite splits the system into two partial binaries: aragonite + brenkite and brenkite + fluorite. An aragonite-brenkite eutectic is situated near 1080°C. An eutectic melt contains 40 mol% CaF2. Brenkite melts incongruently at 1100°C, producing fluorite and peritectic liquid containing 48 mol% CaF2. The presence of fluorine lowers the melting temperature of the calcium carbonate by almost 600°C to a temperature corresponding to a continental geotherm with a surface heat flow of 35 mW/m2. Thus, under mantle conditions, fluorine enable a calcium carbonate-rich melt to remain liquid at a much lower temperature (1080°C) than would be possible without the presence of fluorine (1660°C).