...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Contributions to Mineralogy and Petrology >Crystallization thermometers for zircon and rutile
【24h】

Crystallization thermometers for zircon and rutile

机译：锆石和金红石结晶温度计

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Zircon and rutile are common accessory minerals whose essential structural constituents, Zr, Ti, and Si can replace one another to a limited extent. Here we present the combined results of high pressure-temperature experiments and analyses of natural zircons and rutile crystals that reveal systematic changes with temperature in the uptake of Ti in zircon and Zr in rutile. Detailed calibrations of the temperature dependencies are presented as two geothermometers-Ti content of zircon and Zr content of rutile-that may find wide application in crustal petrology. Synthetic zircons were crystallized in the presence of rutile at 1-2 GPa and 1,025-1,450 deg C from both silicate melts and hydrother-mal solutions, and the resulting crystals were analyzed for Ti by electron microprobe (EMP). To augment and extend the experimental results, zircons hosted by five natural rocks of well-constrained but diverse origin (0.7-3 GPa; 580-1,070 deg C) were analyzed for Ti, in most cases by ion microprobe (IMP). The combined experimental and natural results define a log-linear dependence of equilibrium Ti content (expressed in ppm by weight) upon reciprocal temperature: log(Ti_(zircon)) = (6.01 ± 0.03) - I (K) In a strategy similar to that used for zircon, rutile crystals were grown in the presence of zircon and quartz (or hydrous silicic melt) at 1-1.4 GPa and 675-1,450 deg C and analyzed for Zr by EMP. The experimental results were complemented by EMP analyses of rutile grains from six natural rocks of diverse origin spanning 0.35-3 GPa and 470-l,070 deg C. The concentration of Zr (ppm by weight) in the synthetic and natural rutiles also varies in log-linear fashion with T~(-1): log(Zr_(rutile)) = (7.36 + - 0.10) - The zircon and rutile calibrations are consistent with one another across both the synthetic and natural samples, and are relatively insensitive to changes in pressure, particularly in the case of Ti in zircon. Applied to natural zircons and rutiles of unknown provenance and/or growth conditions, the thermometers have the potential to return temperatures with an estimated uncertainty of + - 10 deg or better in the case of zircon and + - 20 deg or better in the case of rutile over most of the temperature range of interest (approx 400-l,000 deg C). Estimates of relative temperature or changes in temperature (e.g., from zoning profiles in a single mineral grain) made with these thermometers are subject to analytical uncertainty only, which can be better than + - 5 deg depending on Ti or Zr concentration (i.e., temperature), and also upon the analytical instrument (e.g., IMP or EMP) and operating conditions.
机译：锆石和金红石是常见的辅助矿物，其基本结构成分Zr，Ti和Si可以在有限的程度上相互替代。在这里，我们介绍了高压-高温实验以及对天然锆石和金红石晶体的分析的综合结果，揭示了锆石中Ti和金红石中Zr吸收随温度的系统变化。温度相关性的详细校准以两个地热仪表示-锆石的Ti含量和金红石的Zr含量-可能在地壳岩石学中得到广泛应用。在金红石存在的情况下，在1-2 GPa和1,025-1,450℃下，从硅酸盐熔体和水热溶液中结晶出合成锆石，并用电子探针（EMP）分析所得晶体的Ti。为了扩大和扩展实验结果，在大多数情况下，通过离子微探针（IMP）分析了由5个天然岩石制成的锆石，其中5个天然岩石具有良好的约束但来源广泛（0.7-3 GPa; 580-1,070℃）。实验和自然结果的组合定义了平衡Ti含量（以重量ppm表示）对温度的对数线性依赖性：log（Ti_（zircon））=（6.01±0.03）-I（K）在锆石和石英（或含水硅熔体）存在的条件下，用于锆石的金红石晶体在1-1.4 GPa和675-1450摄氏度下生长，并通过EMP分析Zr。通过对EMP分析来分析六种不同来源的天然金红石晶粒的金红石晶粒，这些金红石的晶格范围为0.35-3 GPa和470-l，070℃。合成金红石和天然金红石中Zr的浓度（重量ppm）在T〜（-1）的对数线性方式：log（Zr_（金红石））=（7.36 +-0.10）-锆石和金红石标定在合成样品和天然样品中彼此一致，并且相对不敏感改变压力，尤其是锆石中的Ti。应用于来源和/或生长条件未知的天然锆石和金红石时，温度计具有返回温度的潜力，在锆石的情况下，估计不确定度为+-10度或更高，而在锆石的情况下，不确定度为+-20度或更好。在大部分目标温度范围（约400-l，000摄氏度）下，金红石型。用这些温度计估算的相对温度或温度变化（例如，根据单个矿物颗粒的分区曲线）仅受分析不确定性的影响，取决于Ti或Zr的浓度（即温度），其不确定性可能优于+-5度。 ），以及分析仪器（例如IMP或EMP）和操作条件。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号