Geophysical Detection of the Hydrothermal Alteration Footprints of Ore Deposits with GOCAD-SKUA

John McGaughey and Glenn Pears and James Reid. ( 2018 )
in: 2018 Ring Meeting, ASGA

Abstract

Modern mineral exploration means searching for new ore deposits that are deep or under surficial cover, where there is no expectation of a direct ore deposit signature in exploration data. The deposit, however, is part of a mineralized system with alteration assemblages that may extend kilometres. The architecture of ore deposit systems is generally understood in terms of alteration domains—the deposit “footprint”—and exploration strategy can thus focus on the identification of such domains. In many cases, the spatial relationships of alteration domains provide a means to vector towards the ore deposit. Potential fields data with extensive coverage are common, and high-quality airborne magnetic data are nearly ubiquitous in modern mineral exploration. The use of geophysical data is appealing because, although it does not directly respond to rock chemistry, it provides the greatest and most uniform areal data coverage. In the age of deep and undercover exploration, direct recognition of footprint-scale hydrothermal alteration from geophysical data is the holy grail of geophysical interpretation. We have developed a workflow in SKUA-GOCAD for interpreting subtle alteration signatures from geophysical data, based on the separation of homogeneous, formational, primary and inhomogeneous, alteration-induced, secondary contributions to the earth’s physical property distribution.

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BibTeX Reference

@INPROCEEDINGS{,
    author = { McGaughey, John and Pears, Glenn and Reid, James },
     title = { Geophysical Detection of the Hydrothermal Alteration Footprints of Ore Deposits with GOCAD-SKUA },
 booktitle = { 2018 Ring Meeting },
      year = { 2018 },
 publisher = { ASGA },
  abstract = { Modern mineral exploration means searching for new ore deposits that are deep or under surficial cover, where there is no expectation of a direct ore deposit signature in exploration data. The deposit, however, is part of a mineralized system with alteration assemblages that may extend kilometres. The architecture of ore deposit systems is generally understood in terms of alteration domains—the deposit “footprint”—and exploration strategy can thus focus on the identification of such domains. In many cases, the spatial relationships of alteration domains provide a means to vector towards the ore deposit. Potential fields data with extensive coverage are common, and high-quality airborne magnetic data are nearly ubiquitous in modern mineral exploration. The use of geophysical data is appealing because, although it does not directly respond to rock chemistry, it provides the greatest and most uniform areal data coverage. In the age of deep and undercover exploration, direct recognition of footprint-scale hydrothermal alteration from geophysical data is the holy grail of geophysical interpretation. We have developed a workflow in SKUA-GOCAD for interpreting subtle alteration signatures from geophysical data, based on the separation of homogeneous, formational, primary and inhomogeneous, alteration-induced, secondary contributions to the earth’s physical property distribution. }
}