Locally Resolved Stress‐State in Samples During Experimental Deformation: Insights Into the Effect of Stress on Mineral Reactions

Understanding conditions in the Earth's interior requires data derived from laboratory experiments. Such experiments provide important insights into under which mineral reactions take place as well processes that control localization of deformation deep Earth. We performed Griggs-type general shear combination with numerical models, based on continuum mechanics, to quantify effect evolving sample geometry experimental assembly. The investigated system is constituted by CaCO3 and are near calcite-aragonite phase transition. All samples show a heterogeneous distribution two polymorphs after deformation. This interpreted result local stress variations. These variations agreement observed phase-transition patterns grain-size gradients across sample. comparison mechanical models provides parameters during Our results that, despite use homogeneous material (here calcite), develop due geometry. indicates aragonite formation primarily controlled spatial parameters. Furthermore, we monitor maximum pressure σ1 experienced every part our model domain for given amount time. document (mean stress) values responsible transformation. Therefore, if role thermodynamic potential similar experiments, an accurate description state required.