Abstract
Sandstone is the most significant rock type in the Natal Group, and widely extended into
the Marianhill Formation. Due to prevalence within the Natal Basin it is widely used as
aggregate material therefore it is important to study the physical properties and their
relative effect to the mechanical properties. Literature is rather limited, so this study is
attempting to investigate the published data, applying the approach of self-organising
maps and data-mining techniques in order to extract new knowledge and give further
insight into the relationships amongst sandstone petrographic, physical and mechanical
characteristics. SOM-based analysis distinguished three clusters, with similar
petrographic, physical, geotechnical characteristics, which led to the identification of
different lithofacies. Significant parameters dictating cluster identification, are the type of
grain contact, void space, packing density, and amount of silica cement.