Quantifying the error of 2D bulk chondrule analyses using a computer model to simulate chondrules (SIMCHON) Quantifying the error of 2D bulk chondrule analyses
Quantifying the error of 2D bulk chondrule analyses using a computer model to simulate chondrules (SIMCHON) Quantifying the error of 2D bulk chondrule analyses
复制标题
使用计算机模型模拟球粒来量化 2D 整体球粒分析的误差 (SIMCHON) 量化 2D 整体球粒分析的误差
DOI：
10.1111/j.1945-5100.2010.01040.x
复制
发表时间：
2010
影响因子：
2.2
通讯作者：
HEZEL D
中科院分区：
文献类型：
--
作者：
HEZEL D
体球粒组成对宇宙化学中的许多问题都很重要，然而，可用的体球粒数据集的数量仍然很少。一个主要原因是确定大块球粒组成的困难。一种常用的技术是从陨石切片中获得2D大块球粒组成。这种技术有一个误差，我们在这里首次使用称为SIMCHON的球粒的数学模型进行量化。理论计算的误差相比，我们确定从连续切片的8个Efremovka陨石球粒的错误。从这两种方法获得的误差是非常一致的，证明我们的数学模型产生可靠的错误，可以分配给2D散装球粒组成。这些错误允许一个更好的解释2D散装球粒数据。我们提供了一个表，包含典型的错误的2D大块组成的斑状球粒。误差在± <1 - 30相对%的范围内。对于宇宙化学中的许多问题来说，这应该是可以接受的。研究了球粒内部化学分层的影响和球粒周围边缘的出现，以及不透明相和其他辅助相的出现。提供了一个电子表格，能够计算任何所需的球粒矿物成分的误差。BO球粒有一个可以忽略不计的误差，但它是不可能提供合理的误差估计与火成边缘BO球粒。放射状辉石球粒的误差可以忽略不计。
Bulk chondrule compositions are important to many questions in cosmochemistry, however, the number of available bulk chondrule data sets is still small. A main reason for this is the difficulties of determining bulk chondrule compositions. A commonly used technique is to obtain 2D bulk chondrule compositions from meteorite sections. This technique has an error that we quantify here for the first time using a mathematical model of a chondrule called SIMCHON. The theoretically calculated errors are compared to errors that we determined from serial sectioning of eight Efremovka chondrules. The errors obtained from both approaches are in excellent agreement, proving that our mathematical model produces reliable errors that can be assigned to 2D bulk chondrule compositions. These errors allow a much better interpretation of 2D bulk chondrule data. We provide a table that contains typical errors for 2D bulk compositions of porphyritic chondrules. The errors are in the range of ±<1–30 relative‐%. This should be acceptable for many problems in cosmochemistry. The effect of a chemical layering inside chondrules and the occurrence of a rim around them, as well as the occurrence of opaque and other accessory phases have been studied. A spreadsheet is provided that enables the calculation of errors for any desired chondrule mineral composition. BO chondrules have a negligible error, but it is impossible to provide reasonable error estimates for BO chondrules with an igneous rim. Radial pyroxene chondrules have negligible errors.