Nucleation theory applied to the development of contrasting garnet crystal densities
Nucleation theory applied to the development of contrasting garnet crystal densities
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成核理论应用于对比石榴石晶体密度的开发
DOI：
10.1007/s00410-021-01879-1
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发表时间：
2022
影响因子：
3.5
通讯作者：
Wolfe, Oliver M.
中科院分区：
文献类型：
--
作者：
Spear, Frank S.;Wolfe, Oliver M.
在新英格兰的三个地方，对含有大量小石榴石（高晶体密度或HiCD）和少量大石榴石（低晶体密度或LoCD）的岩石进行了检查，以限制石榴石成核的超跃程度。在9个样品中测量了石榴石晶体密度，范围从几个晶体/cm ~ 3到超过100 × 106个晶体/cm ~ 3。石榴石中石英（QuiG）气压测定表明，HiCD样品中的石英夹杂物等压线与LoCD样品中的石英夹杂物等压线在误差范围内，表明成核的P-T条件相似。成核温度更难以约束，但几条推理线表明，HiCD和LoCD样品在相似的P-T条件下成核石榴石，在所有情况下，均显著高于计算的平衡石榴石反应。使用最大驱动力（切线或平行切线）方法计算的石榴石成核亲和力范围为0.15 - 0.5 kJ/mol-O（LoCD样品）至1.4-4.3 J/mol-O（HiCD样品）（使用SPaC热力学数据集），以及0.65-1.8 kJ/mol-O（LoCD样品）至3.0-6.1 J/mol-O（HiCD样品）（使用HP 11热力学数据集）。经典成核理论的应用允许将成核时的表面能限制在约0.022-0.045 J/m2，这取决于所使用的热力学数据集，并对速率方程中的指前常数进行限制。为什么在石榴石成核之前，邻近的样品会积累如此不同的亲和力，这个问题还没有答案，但很明显，除了化学亲和力之外，还有其他因素也很重要。
Rocks that contain numerous small garnets (high crystal density or HiCD) and few large garnets (low crystal density or LoCD) have been examined from three localities in New England to constrain the degree of overstepping for garnet nucleation. Garnet crystal densities have been measured in nine samples and range from a few crystals/cm3to over 100 × 106crystals/cm3. Quartz-in-garnet (QuiG) barometry reveals that the quartz inclusion isomekes in HiCD samples are within error the same pressure as quartz inclusion isomekes in LoCD samples, suggesting similar P–T conditions of nucleation. Temperature of nucleation is more difficult to constrain but several lines of reasoning suggest that both HiCD and LoCD samples nucleated garnet at similar P–T conditions, which are, in all cases, significantly above the calculated equilibrium garnet-in reaction. Affinities for garnet nucleation calculated using the Maximum Driving Force (MDF or parallel tangent) approach range from 0.15 to 0.5 kJ/mol-O in the LoCD samples to 1.4–4.3 J/mol-O in the HiCD samples using the SPaC thermodynamic dataset and 0.65–1.8 kJ/mol-O in the LoCD samples to 3.0–6.1 J/mol-O in the HiCD samples using the HP11 thermodynamic dataset. Application of classical nucleation theory permits constraining the surface energy at the time of nucleation to approximately 0.022–0.045 J/m2depending on the thermodynamic dataset used and places limits on the pre-exponential constant in the rate equation. The question of why proximal samples should accumulate such different amounts of affinity before garnet nucleates is unanswered, but it is clear that some factor other than just the amount of chemical affinity must be important.
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影响因子：
3.9
作者：
F. Spear
通讯作者：
F. Spear
影响因子：
5.3
作者：
A. Schmidt;A. Pourteau;O. Candan;R. Oberhänsli
通讯作者：
A. Schmidt;A. Pourteau;O. Candan;R. Oberhänsli
智利中南部沿海科迪勒拉山脉巴伊亚曼萨高压低温杂岩中锰铝榴石石英岩（小叶）的变质演化
DOI：
--
发表时间：
2001
期刊：
影响因子：
--
作者：
A. Willner;Sabine Pawlig;H. Massonne;F. Hervé
通讯作者：
F. Hervé
影响因子：
3.5
作者：
Gaidies, F.;Pattison, D. R. M.;de Capitani, C.
通讯作者：
de Capitani, C.
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影响因子：
2.6
作者：
Castro, Adrian E.;Spear, Frank S.
通讯作者：
Spear, Frank S.