Incomplete Crack Sealing Causes Localization of Fracturing in Hydrothermal Quartz Veins

Cyclic microfracturing and epitaxial crystal growth have long been recognized in crack-seal veins, but an understanding of a single cycle is still missing. Here we present phase-field model that includes both fracture mechanics crack propagation, on the walls, repeating this multiple times polycrystalline, microporous quartz rock. Our simulations two end members: If vein completely seals, it stronger than host rock, cracking delocalized, forming many single-seal microveins. Incomplete sealing makes weaker rock localizes new inside vein, leading to multi-crack-seal. We suggest degree key parameter hydrothermal systems multi-crack-seal veins are long-lived, sites mechanical weakness. generalize approach conduct probabilistic between these types, show how microveins emerge.