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首页> 外文期刊>Catena: An Interdisciplinary Journal of Soil Science Hydrology-Geomorphology Focusing on Geoecology and Landscape Evolution >Characterization of granitoid and gneissic weathering profiles of the Mucone River basin (Calabria, southern Italy).
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Characterization of granitoid and gneissic weathering profiles of the Mucone River basin (Calabria, southern Italy).

机译：穆科涅河流域（意大利南部卡拉布里亚）的花岗岩和片麻岩风化剖面特征。

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The paper deals with the development of a multidisciplinary research on weathering profiles of granitoid and gneissic rocks related to tectonic and landscape evolution of the western Sila Grande Massif (Calabria, southern Italy). Field scale observations and petrographical and mineralogical features are used to characterize in detail the weathering processes. The weathering profiles of the granitoid cut slopes are generally simple showing a progressive weathering increase toward the top of the slopes, whereas the weathering profiles of the gneissic cut slopes are generally complex with irregularities in the spatial distribution of weathered horizons. The microfabric and petrographic analyses show that gneissic samples (classes V-VI of weathering grade) are characterized by higher percentage of altered minerals and microfracture and void rather than granitoid samples (classes V-VI of weathering grade). The main mineralogical changes concern the partial transformation of biotite and the partial destruction of feldspars (mainly plagioclases), associated with the neoformation of secondary minerals (clay minerals and Fe-oxides) and with a substitution of the original rock fabric. Neoformed clay minerals and ferruginous products replaced feldspars and biotite during the most advanced weathering stage. Referred as physical changes coupled with chemical variations, the final results of weathering process are a soil-like material characterized by sand-gravel grain-size fraction for the granitoid rocks and by both silt-clay and sand-silt grain-size fraction for the gneissic rocks. This generally produces a greater value of the SGI (Sand Generation Index) for granitoids and explains the great productivity in sandy deposits of this lithology.
机译：本文涉及与西拉格兰德地块（意大利南部卡拉布里亚）的构造和景观演化有关的花岗岩和片麻岩岩石风化剖面的多学科研究的发展。现场规模的观测以及岩石学和矿物学特征被用来详细表征风化过程。花岗岩切面斜坡的风化剖面通常很简单，显示出向斜坡顶部逐渐增加的风化，而片麻岩切面斜坡的风化剖面通常复杂，并且风化层的空间分布不规则。微观结构和岩石学分析表明，片麻岩样品（风化等级为V-VI级）的特征是矿物成分和微裂缝和孔隙的变化百分比高于花岗岩样品（风化等级为V-VI级）。主要的矿物学变化涉及黑云母的部分转变和长石（主要是斜长石）的部分破坏，与次生矿物（粘土矿物和铁氧化物）的新形成有关，并与原始岩石构造的替代有关。在最高级的风化阶段，新成型的粘土矿物和铁质产品替代了长石和黑云母。所谓的物理变化加上化学变化，风化过程的最终结果是一种类似土壤的物质，其特征是花岗岩岩石的砂砾粒度级分，而沙质粘土和沙子淤泥粒度级分均片麻岩。对于花岗岩类，这通常会产生更大的SGI（沙尘生成指数）值，并解释了这种岩性在沙质沉积物中的高生产率。

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