Díaz, C, Lopez, J & Ramos, AA 2025, 'Assessment of geomechanical properties for slope stability analysis in carbonaceous sedimentary rocks', in JJ Potter & J Wesseloo (eds), SSIM 2025: Fourth International Slope Stability in Mining Conference, Australian Centre for Geomechanics, Perth, https://doi.org/10.36487/ACG_repo/2535_49 (https://papers.acg.uwa.edu.au/p/2535_49_Diaz/) Abstract: Slope stability assessment in carbonaceous sedimentary rock masses poses significant challenges due to their inherent structural complexity, low strength and variable weathering profiles. This study focuses on an open pit mine in the Dominican Republic, where a distinctive combination of tropical climate, tectonic influence, and carbon-rich lithologies creates a demanding geotechnical setting. Rather than relying solely on standard empirical methods, the research integrates field and historical laboratory data into a calibrated threedimensional limit equilibrium model tailored to the carbonaceous domain. Kinematic assessments, informed by detailed structural mapping, are contextualised within a design acceptance framework specific to the site’s geological and operational constraints. The novelty of this approach lies in adapting conventional tools to account for local variability in rock mass behaviour and failure control, allowing for more precise slope design and risk mitigation. The outcomes demonstrate the value of early geomechanical characterisation and continuous model refinement to optimise slope performance and enhance long-term operational safety. Keywords: geomechanics, rock mass characterisation, structural mapping, slope stability, kinematic analysis, limit equilibrium, carbonaceous sediment, geotechnical risk management.