PT - JOURNAL ARTICLE AU - Wang, Qiqi AU - Laubach, S. E. AU - Gale, J. F. W. AU - Ramos, M. J. TI - Quantified fracture (joint) clustering in Archean basement, Wyoming: application of the normalized correlation count method AID - 10.1144/petgeo2018-146 DP - 2019 Nov 01 TA - Petroleum Geoscience PG - 415--428 VI - 25 IP - 4 4099 - http://pg.lyellcollection.org/content/25/4/415.short 4100 - http://pg.lyellcollection.org/content/25/4/415.full SO - Petroleum Geoscience2019 Nov 01; 25 AB - We demonstrate statistically significant self-organized clustering over a length scale range from 10−2 to 101 m for north-striking opening-mode fractures (joints) in Late Archean Mount Owen Quartz Monzonite. Spatial arrangement is a critical fracture network attribute that until recently has only been assessed qualitatively. We use normalized fracture intensity plots and the normalized correlation count (NCC) method of Marrett et al. to discriminate clustered from randomly placed or evenly spaced patterns quantitatively over a wide range of length scales and to test the statistical significance of the resulting patterns. We propose a procedure for interpreting cluster patterns on NCC diagrams generated by the freely available spatial analysis software CorrCount. Results illustrate the efficacy of NCC to measure fracture clustering patterns in texturally homogeneous Archean granitic rock in a setting distant (>2 km) from folds or faults. In their current geological setting, these regional fractures are conduits for water flow and their patterns – and the NCC approach to defining clusters – may be useful guides to the spatial arrangement style and clustering magnitude of conductive fractures in other, less accessible fractured basement rocks.Thematic collection: This article is part of the Naturally Fractured Reservoirs collection available at: https://www.lyellcollection.org/cc/naturally-fractured-reservoirs