英国爱丁堡大学James Gilgannon的研究小组揭示了弹性应力可形成变质组构。相关论文于2023年12月19日发表在《地质学》杂志上。

研究人员使用时间分辨同步加速器进行了微断层扫描实验，实验显示，经历弹性差应力的反应和变形样品产生了与最大主应力正交的组构，从而对这一争议进行了补充并取得了重大进展。这种组构在反应的早期就形成了，可以证明它的形成与应变无关。研究结果非常显著，因为非静水应力状态是一种常见的地质现象。

研究人员还将报告的组构与岩浆侵入和地震周期的瞬时和周期性差异应力联系起来，本文数据为意大利Val Malenco和西班牙Cerro del Almirez的经典而神秘的蛇纹石组构的解释建立了新的基础。

据介绍，详述变质岩中的应力和反应之间的关系一直是有争议的，大部分争论集中在理论上。

附：英文原文

Title: Elastic stresses can form metamorphic fabrics

Author: James Gilgannon, Damien Freitas, Roberto Emanuele Rizzo, John Wheeler, Ian B. Butler, Sohan Seth, Federica Marone, Christian M. Schlepütz, Gina McGill, Ian Watt, Oliver Plümper, Lisa Eberhard, Hamed Amiri, Alireza Chogani, Florian Fusseis

Issue&Volume: 2023-12-19

Abstract: Detailing the relationship between stress and reactions in metamorphic rocks has been controversial, and much of the debate has centered on theory. Here, we add to this discussion and make a major advance by showing in time-resolved synchrotron microtomography experiments that a reacting and deforming sample experiencing an elastic differential stress produces a fabric orthogonal to the largest principal stress. This fabric forms very early in the reaction and can be shown to be unrelated to strain. The consequences of this are significant because a non-hydrostatic stress state is a very common geological occurrence. Our data provide the basis for new interpretations of the classical, and enigmatic, serpentine fabrics of Val Malenco, Italy, and Cerro del Almirez, Spain, where we relate the reported fabrics to transient, and cyclical, differential stresses from magma intrusion and the earthquake cycle.

DOI: 10.1130/G51612.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G51612.1/631690/Elastic-stresses-can-form-metamorphic-fabricsredirectedFrom=fulltext