摘要
The purpose of this work is to study the weathering processes of the granulite rocks of the Serre Massif (southern Calabria,Italy) using a multidisciplinary approach based on field studies,geochemical modeling,and minero?petrographical analyses.The granulite rocks are plagioclase-rich with minor amphibole,clinopyroxene,orthopyroxene,biotite,and garnet and their texture are coarse-grained.The reaction path modeling was performed to simulate the evolution of groundwaters upon interaction with local granulite by means of the software package EQ3/6,version 8.0a.Simulations were performed in kinetic (time) mode under a closed system at a constant temperature of 11.5℃,(which reproduces the average temperature of local area) and fixing the fugacity of CO2 at 10-2.34 bar (mean value).During the most advanced stage of weathering the main mineralogical changes are: partial destruction and transformation of biotite and plagioclase associated with neoformation of ferruginous products and secondary clay minerals producing a change in the origin rock fabric.The secondary solid phases observed during the geochemical modeling (kaolinite,vermiculite and ferrihydrite) are similar to those found in this natural system.Thus,the soil-like material mainly characterized by mostly sand to gravel grain-size fractions is the final result of the weathering processes.
