Nucleation and growth history of garnet in metamorphic rocks: 2D and 3D petrological insights

Historia de nucleación y crecimiento del granate en rocas metamórficas: Perspectivas petrológicas en 2D y 3D

Abstract

This study investigates garnet nucleation and growth in metamorphic rocks through integrated controlled serial sectioning, high-resolution backscattered electron (BSE) imaging, and three-dimensional reconstruction. Implementation of a systematic material removal protocol significantly enhanced surface reproducibility and analytical consistency relative to conventional manual preparation methods. A dataset of 2,100 BSE images enabled the generation of high-resolution mosaics via automated image stitching. Digital processing and algorithmic segmentation allowed quantitative characterization of particle size distributions (PSD) across 50 consecutive layers. The resulting Gaussian PSD indicates spatial and temporal variability in nucleation rates and growth regimes, providing kinetic constraints on crystallization processes within the Arquía Complex. The integration of advanced imaging and computational modeling establishes a quantitative petro-textural framework for 2D and 3D analysis of metamorphic rocks, enabling rigorous assessment of grain size, morphology, orientation proxies, and spatial distribution of mineral phases, pores, and fractures. These parameters are critical for interpreting metamorphic reactions and reconstructing tectonometamorphic evolution. Our findings provide new quantitative constraints on garnet crystallization mechanisms and their role in regional metamorphic development.