A cluster-based multiparametric similarity test for the compartmentalization of crystalline rocks into structural domains

Abstract

Usually, fracture sampling studies comprise the collection of several fracture samples that involve many fracture clusters. Grouping fracture samples into structural domains is generally useful for geologists, hydrogeologists and geomechanicians as a region of fractured rock is subdivided into subregions with similar behaviour in terms of their hydromechanical properties. One of the common methods used for grouping fracture samples into structural domains considers the fracture orientation of clusters and ignores several fracture parameters, such as fracture spacing, aperture and persistence, which are important for fluid circulation in the rock mass. In this study, we proposed a new cluster-based similarity method that considers the orientation of clusters as well as the clusters’ aperture, persistence and fracture spacing. Field investigations were conducted in the Grenville geological province of the Canadian Shield in the Lanaudière region, Quebec, Canada, where fractures were sampled from 30 outcrops and four boreholes. The proposed method is more suitable than other methods, and has applications in hydrogeology, rock mechanics and particularly in studies of fluid circulation in the rock mass. In addition, a method for the compartmentalization of a given study area into structural domains by means of Voronoi diagrams is also proposed.