DOI: 10.1016/j.tecto.2021.228889
论文题名: Mapping structural complexity using geophysics: A new geostatistical approach applied to greenstone belts of the southern Superior Province, Canada
作者: Montsion R.M. ; Perrouty S. ; Lindsay M.D. ; Jessell M.W. ; Frieman B.M.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 812 语种: 英语
中文关键词: Aeromagnetic auto-detection
; Fisher statistics
; Mineral exploration
; Orogenic gold
; Structural complexity
; Superior Craton
英文关键词: Deposits
; Dispersions
; Learning algorithms
; Machine learning
; Mapping
; Population statistics
; Statistical mechanics
; Structural geology
; Archean greenstone belts
; Geological interpretation
; Geological mapping
; Geostatistical approach
; Highest resolutions
; Sharp boundaries
; Statistical tools
; Structural complexity
; Gold deposits
; aeromagnetic survey
; algorithm
; complexity
; data interpretation
; deformation mechanism
; detection method
; geological mapping
; greenstone belt
; lineament
; mineral exploration
; ore deposit
; orogeny
; quantitative analysis
; shear zone
; structural geology
; Canada
; Superior Province
; Martes
英文摘要: With the increasing size and complexity of geoscientific databases, statistical tools and machine learning algorithms are needed to highlight subtle patterns within dense data clouds and reduce human-related bias in geological mapping. This study presents a new tool that maps structural complexity using circular variance and spherical dispersion in two Archean greenstone belts near Dryden and Timmins in the Superior Province, Ontario. Structural complexity quantitatively highlights areas where structures are folded, juxtaposed, and/or parallel. Bedding measurements and autodetected aeromagnetic lineaments are used as inputs to test if structural complexity can refine or add confidence to existing geological interpretations. Linear, low variance trends frequently delineate the location and extent of deformation zones, which likely reflect parallel transposed fabrics in high strain corridors. Areas of high variance spatially correlate with fold traces. Sharp boundaries between high and low variance anomalies are interpreted as faults and/or shear zones that juxtapose structural blocks. The near continuous and representative nature of autodetected magnetic lineaments was effective in capturing structural complexity at a regional scale; however, spherical dispersion captured the highest resolution of structural complexity at local scales (<1:30000). Key considerations when performing structural complexity analysis are scale, data density, and optimization of input parameters (e.g., neighborhood radius, lineament length, minimum neighborhood populations). Gold deposits are found <~1700 m from low (< μ - 1σ) and < ~1500 m from high circular variance anomalies (> μ + 1σ). Additionally, the gold grade of large deposits (> 1 Moz) increases with proximity to high variance anomalies. When paired with expert knowledge, these techniques will increase repeatability in future exploration endeavors, making exploration a more rigorous process with increased confidence. © 2021 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170866
Appears in Collections: 气候变化与战略
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作者单位: Mineral Exploration Research Centre, Harquail School of Earth Sciences, Goodman School of Mines, Laurentian University, Sudbury, ON P3E 2C6, Canada; Centre for Exploration Targeting, School of Earth Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, Australia
Recommended Citation:
Montsion R.M.,Perrouty S.,Lindsay M.D.,et al. Mapping structural complexity using geophysics: A new geostatistical approach applied to greenstone belts of the southern Superior Province, Canada[J]. Tectonophysics,2021-01-01,812