Wide-blocky veins explained by dependency of crystal growth rate on fracture surface type: Insights from phase-field modeling

Spruzeniece, L. , Späth, M., Urai, J. L., Ukar, E., Selzer, M. and Nestler, B. (2021) Wide-blocky veins explained by dependency of crystal growth rate on fracture surface type: Insights from phase-field modeling. Geology, 49(6), pp. 641-646. (doi: 10.1130/G48472.1)

Full text not currently available from Enlighten.

Abstract

Vein microstructures contain a wealth of information on coupled chemical and mechanical processes of fracturing, fluid transport, and crystal growth. Numerical simulations have been used for exploring the factors controlling the development of vein microstructures; however, they have not been quantitatively validated against natural veins. Here we combined phase-field modeling with microtextural analysis of previously unexplained wide-blocky calcite veins in natural limestone and of the fresh fracture surface in this limestone. Results show that the wide-blocky vein textures can only be reproduced if ∼10%–20% of crystals grow faster than the rest. This fraction corresponds to the amount of transgranularly broken grains that were observed on the experimental fracture surfaces, which are dominantly intergranular. We hypothesize that transgranular fractures allow faster growth of vein minerals due to the lack of clay coatings and other nucleation discontinuities that are common along intergranular cracks. Our simulation results show remarkable similarity to the natural veins and reproduce the nonlinear relationship between vein crystal width and vein aperture. This allows accurate simulations of crystal growth processes and related permeability evolution in fractured rocks.

Item Type:Articles
Additional Information:We thank the German Science Foundation (DFG) for funding this project grants (NE 822/34-1, UR 64/171). Ukar acknowledges grant DE-FG02-03ER15430 from the Chemical Sciences, Geosciences, and Biosciences (CSGB) Division, Office of Basic Energy Sciences, U.S. Department of Energy, for financial support/
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Spruzeniece, Dr Liene
Authors: Spruzeniece, L., Späth, M., Urai, J. L., Ukar, E., Selzer, M., and Nestler, B.
College/School:College of Science and Engineering > School of Geographical and Earth Sciences
Journal Name:Geology
Publisher:Geological Society of America
ISSN:0091-7613
ISSN (Online):1943-2682

University Staff: Request a correction | Enlighten Editors: Update this record