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TitreImproved mapping of basement faults in the northeast Thelon Basin by source edge processing of aeromagnetic data
AuteurTschirhart, V; Morris, W A; Jefferson, C
Source38th Annual Yellowknife Geoscience Forum, abstracts of talks and posters; par Palmer, E; Northwest Territories Geoscience Office, Yellowknife Geoscience Forum Abstracts Volume vol. 2010, 2010 p. 65
Année2010
Séries alt.Secteur des sciences de la Terre, Contribution externe 20100278
RéunionYellowknife Geoscience Forum; Yellowknife; CA; Novembre 16-18, 2010
Documentpublication en série
Lang.anglais
Mediapapier; en ligne; numérique
Formatspdf
ProvinceNunavut
SNRC66A; 66B; 66C/01; 66C/02; 66C/03; 66C/06; 66C/07; 66C/08; 66C/09; 66C/10; 66C/11; 66C/14; 66C/15; 66C/16; 66D/01; 66D/02; 66D/03; 66E/01; 66E/02; 66E/03; 66E/04; 66E/05; 66E/06; 66E/07; 66E/08; 66E/09; 66E/10; 66E/11; 66E/12; 66F/01; 66F/02; 66F/03; 66F/04; 66F/05; 66F/06; 66F/07; 66F/08; 66F/09; 66F/10; 66F/11; 66F/12
Lat/Long OENS-101.5000 -96.3333 65.7500 64.0833
Sujetsgéologie du socle; caractéristiques structurales; failles; levés géophysiques; interprétation aéromagnétique; Bassin de Thelon ; géologie structurale
ProgrammeUranium, GEM : La géocartographie de l'énergie et des minéraux
LiensOnline - En ligne
Résumé(disponible en anglais seulement)
Within the Thelon Basin of Nunavut, northeast of the border with Northwest Territories, the unconformity surface is located at depths as great as 1000 m (Tschirhart et al., submitted). In the search for unconformity uranium deposits, analysis of reactivated faults is an important guide. Detection of faults at surface within the region has included geologic mapping and lineament analysis on topographic and potential field data. Field mapping has identified structures that can be projected laterally using spatial analysis of lineaments, but projecting to the unconformity at depth is problematic. Lineament analysis may also help to determine which faults have been re-activated and altered at or near surface. Myriad lineaments can be identified from topographic data, requiring screening and qualification with geophysical data to prioritize importance and linkages with mapped structures. For regional framework analysis of the prospective Thelon Basin, a non-invasive approach using public domain data is needed to estimate the locations of buried faults that may have offset the unconformity surface but are of uncertain relationship, if any, to surface-mapped structures. Source edge detection analysis of aeromagnetic data offers an objective and quantitative solution to this challenge.
Source edge detection and textural analysis have been used extensively in industry and literature to locate magnetically anomalous source body edges and regions of structural complexity, respectively. A multitude of results are generated using both techniques creating a cluttered image, where it is difficult to distinguish real edges from noise. A new utility is introduced to delineate faults from aeromagnetic data. By gridding the dip-direction computed by the Blakely algorithm, lineaments marking offsets of the magnetically susceptible geology become evident. A multitude of new faults have been identified while validating, refining or rejecting faults inferred from geological discontinuities and linear elevation features. This tool simplifies conventional source-edge detection or textural analysis, effectively reducing clutter and distinguishing true maxima from noise. It has promise for comprehensive mapping of fault symmetries in the basin, understanding its tectonic development and pinpointing prospective intersections.
GEOSCAN ID287191