WISTFUL: Whole‐Rock Interpretative Seismic Toolbox for Ultramafic Lithologies
WISTFUL: Whole‐Rock Interpretative Seismic Toolbox for Ultramafic Lithologies
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DOI：
10.1029/2022gc010329
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发表时间：
2022-08
期刊：
影响因子：
3.7
通讯作者：
William J. Shinevar;O. Jagoutz;M. Behn
中科院分区：
文献类型：
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作者：
William J. Shinevar;O. Jagoutz;M. Behn
为了将测量到的上地幔地震波速度定量转换为温度、密度、成分以及对应性和不确定性，我们引入了超镁铁质岩石的全岩解释地震勘探（WISTFUL）。WISTFUL的基础是一个数据库，包含4，485种超镁铁全岩成分，计算出的矿物模式，弹性模量，以及压力（P）和温度（T）范围内的地震波速度（P = 0.5-6 GPa，T = 200- 1，600 °C），使用吉布斯自由能最小化程序Perple_X。这些数据通过MATLAB®函数、脚本和三个通用用户界面的工具箱进行解释：WISTFUL_relations，绘制计算参数和/或成分之间的关系; WISTFUL_geotherms，计算沿着地热的地震波速度; WISTFUL_inversion，反演地震波速度以获得最佳拟合温度、成分和密度。为了评估我们的方法并量化正演计算误差，我们估计了两个主要的不确定性来源：（a）预测的矿物模式和成分，以及（B）弹性性质和混合方程。为了限制不确定性的第一个来源，我们汇编了122个经过充分研究的超镁铁质捕虏体，它们具有已知的全岩成分、矿物模式和估计的P-T条件。我们比较了所观察到的矿物模式与使用五种不同的热力学固溶体模型预测的模式。Holland等人（2018年，https：//doi.org/10.1093/petrology/egy048）的解模型最好地再现了相位组合（12 vol. %相位均方根误差[RMSE]）和估计的波速。为了评估不确定性的第二个来源，我们比较了40个超镁铁岩的波速测量值与计算的波速，发现非常吻合（Vp RMSE = 0.11 km/s）。WISTFUL可以轻松地分析地震数据集，集成到建模中，并作为一种教育工具。
To quantitatively convert upper mantle seismic wave speeds measured into temperature, density, composition, and corresponding and uncertainty, we introduce the Whole‐rock Interpretative Seismic Toolbox For Ultramafic Lithologies (WISTFUL). WISTFUL is underpinned by a database of 4,485 ultramafic whole‐rock compositions, their calculated mineral modes, elastic moduli, and seismic wave speeds over a range of pressure (P) and temperature (T) (P = 0.5–6 GPa, T = 200–1,600°C) using the Gibbs free energy minimization routine Perple_X. These data are interpreted with a toolbox of MATLAB® functions, scripts, and three general user interfaces: WISTFUL_relations, which plots relationships between calculated parameters and/or composition; WISTFUL_geotherms, which calculates seismic wave speeds along geotherms; and WISTFUL_inversion, which inverts seismic wave speeds for best‐fit temperature, composition, and density. To evaluate our methodology and quantify the forward calculation error, we estimate two dominant sources of uncertainty: (a) the predicted mineral modes and compositions, and (b) the elastic properties and mixing equations. To constrain the first source of uncertainty, we compiled 122 well‐studied ultramafic xenoliths with known whole‐rock compositions, mineral modes, and estimated P‐T conditions. We compared the observed mineral modes with modes predicted using five different thermodynamic solid solution models. The Holland et al. (2018, https://doi.org/10.1093/petrology/egy048) solution models best reproduce phase assemblages (∼12 vol. % phase root‐mean‐square error [RMSE]) and estimated wave speeds. To assess the second source of uncertainty, we compared wave speed measurements of 40 ultramafic rocks with calculated wave speeds, finding excellent agreement (Vp RMSE = 0.11 km/s). WISTFUL easily analyzes seismic datasets, integrates into modeling, and acts as an educational tool.