Deformation-resembling microstructure created by fluid-mediated dissolution-precipitation reactions.
Nat Commun 2017;
8:14032. [PMID:
28128202 PMCID:
PMC5290167 DOI:
10.1038/ncomms14032]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/21/2016] [Indexed: 12/02/2022] Open
Abstract
Deformation microstructures are widely used for reconstructing tectono-metamorphic events recorded in rocks. In crustal settings deformation is often accompanied and/or succeeded by fluid infiltration and dissolution–precipitation reactions. However, the microstructural consequences of dissolution–precipitation in minerals have not been investigated experimentally. Here we conducted experiments where KBr crystals were reacted with a saturated KCl-H2O fluid. The results show that reaction products, formed in the absence of deformation, inherit the general crystallographic orientation from their parents, but also display a development of new microstructures that are typical in deformed minerals, such as apparent bending of crystal lattices and new subgrain domains, separated by low-angle and, in some cases, high-angle boundaries. Our work suggests that fluid-mediated dissolution–precipitation reactions can lead to a development of potentially misleading microstructures. We propose a set of criteria that may help in distinguishing such microstructures from the ones that are created by crystal-plastic deformation.
Microstructural features of deformed rocks are used to reveal deformation stresses and temperatures. Here, the authors conduct experiments showing that misleading microstructures form during fluid-mediated mineral reactions under static conditions, and propose new criteria for microstructure identification.
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