气候变化领域集成服务门户(CCPortal): Evaluating the Formation Pressure of Diamond-Hosted Majoritic Garnets: A Machine Learning Majorite Barometer

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DOI	10.1029/2020JB020604
	Evaluating the Formation Pressure of Diamond-Hosted Majoritic Garnets: A Machine Learning Majorite Barometer
	Thomson A.R.; Kohn S.C.; Prabhu A.; Walter M.J.
发表日期	2021
ISSN	21699313
卷号	126 期号:3
英文摘要	Diamond-hosted majoritic garnet inclusions provide unique insights into the Earth's deep, and otherwise inaccessible, mantle. Compared with other types of mineral inclusions found in sub-lithospheric diamonds, majoritic garnets can provide the most accurate estimates of diamond formation pressures because laboratory experiments have shown that garnet chemistry varies strongly as a function of pressure. However, evaluation using a compilation of experimental data demonstrates that none of the available empirical barometers are reliable for predicting the formation pressure of many experimental majoritic garnets and cannot be applied with confidence to diamond-hosted garnet inclusions. On the basis of the full experimental data set, we develop a novel type of majorite barometer using machine learning algorithms. Cross validation demonstrates that Random Forest Regression allows accurate prediction of the formation pressure across the full range of experimental majoritic garnet compositions found in the literature. Applying this new barometer to the global database of diamond-hosted inclusions reveals that their formation occurs in specific pressure modes. However, exsolved clinopyroxene components that are often observed within garnet inclusions are not included in this analysis. Reconstruction of inclusions, in the 8 cases where this is currently possible, reveals that ignoring small exsolved components can lead to underestimating inclusion pressures by up to 7 GPa (∼210 km). The predicted formation pressures of majoritic garnet inclusions are consistent with crystallization of carbon-rich slab-derived melts in Earth's deep upper mantle and transition zone. © 2021. The Authors.
英文关键词	barometer; machine learning; majoritic garnet; sub-lithospheric diamonds
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187256
作者单位	Department of Earth Sciences, University College London, London, United Kingdom; School of Earth Sciences, University of Bristol, Bristol, United Kingdom; Tetherless World Constellation, Rensselaer Polytechnic Institute, Troy, NY, United States; Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, United States
推荐引用方式 GB/T 7714	Thomson A.R.,Kohn S.C.,Prabhu A.,et al. Evaluating the Formation Pressure of Diamond-Hosted Majoritic Garnets: A Machine Learning Majorite Barometer[J],2021,126(3).
APA	Thomson A.R.,Kohn S.C.,Prabhu A.,&Walter M.J..(2021).Evaluating the Formation Pressure of Diamond-Hosted Majoritic Garnets: A Machine Learning Majorite Barometer.Journal of Geophysical Research: Solid Earth,126(3).
MLA	Thomson A.R.,et al."Evaluating the Formation Pressure of Diamond-Hosted Majoritic Garnets: A Machine Learning Majorite Barometer".Journal of Geophysical Research: Solid Earth 126.3(2021).