The Niagara Escarpment in Hamilton, Ontario, presents significant geohazards, such as block failure, threatening human safety and infrastructure. Despite thorough documentation of the stratigraphy exposed along the escarpment, there remains a lack of quantitative assessment of the rock mass characteristics. This study addresses this gap and offers practical approaches to documenting rock mass characteristics by investigating rock strength properties. The Schmidt hammer (SH), a non-destructive tool widely used in geotechnical and geomorphological research, was used to compare the strength values of rock units exposed along the Niagara Escarpment in Hamilton. Systematic field investigations across selected sites used scanline surveys to measure weathering, fracture continuity, groundwater presence and SH values. The SH rebound values were qualitatively compared with those reported in previous literature and align with lithological expectations. Findings indicate that SH values are significantly influenced by both geographic location and geological formation, with a significant interaction effect. Comparative analysis of rock units in the Ancaster Member of the Goat Island Formation, the Gasport Formation and the Irondequoit Formation showed significant differences (p < 0.005) in rock hardness, with mean SH values of 32.8, 42.2 and 49.1, respectively. These findings demonstrate the necessity of integrating stratigraphic and site-specific geological data into hazard mitigation strategies, as rock hardness influences the stability of the escarpment face. The data reported here demonstrate rock strength variation along the Niagara Escarpment and contribute to the modelling and prediction of geohazards, thereby enhancing geohazard management strategies in similar regions.

Deformation and uplift in the Andes are a result of the subduction of the Nazca plate below South America. The deformation shows variations in structural style and shortening along and across the strike of the orogen, as a result of the dynamics of the subduction system and the features of the upper plate. In this work, we analyse the development of thin-skinned and thick-skinned fold and thrust belts in the Southern Central Andes (30–36°S). The pre-Andean history of the area determined the formation of different basement domains with distinct lithological compositions, as a result of terrane accretions during Palaeozoic time, the development of a widespread Permo-Triassic magmatic province and long-lasting arc activity. Basin development during Palaeozoic and Mesozoic times produced thick sedimentary successions in different parts of the study area. Based on estimations of strength for the different basement and sedimentary rocks, calculated using geophysical estimates of rock physical properties, we propose that the contrast in strength between basement and cover is the main control on structural style (thin- v. thick-skinned) and across-strike localization of shortening in the study area.