Mineralogical, Geochemical, and Physical Signatures of Slip Surfaces in Landslide-prone Area, Yauco, Puerto Rico

This thesis study investigates the mineralogical and geochemical characteristics of soils in Yauco, a region highly prone to landslides, and compares them to those in Utuado, another landslide-affected area within the Cordillera Central. Through field observations and laboratory analyses that include X-ray diffraction (XRD), X-ray fluorescence (XRF), and thermogravimetric analysis (TGA), this research explores how soil composition, geochemistry and mineralogy structure contribute to landslide susceptibility. Given the variability of soils in the vicinity of monitoring sites, combined with evidence for clay-enriched slip planes ~50 - cm deep in soils, this research underscores the importance of integrating soil mineralogical studies into establishing antecedent soil moisture and precipitation intensity thresholds for rainfall-induced landslides and future early-warning systems in Puerto Rico.