Application of the airborne electromagnetic method for Banded Iron-Formation mapping in the Hamersley Province, Western Australia
| Autor: | Doug Kepert, Rory Murray, Regis Neroni |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010504 meteorology & atmospheric sciences
Channel data General Engineering Mineralogy Weathering Terrain engineering.material 010502 geochemistry & geophysics 01 natural sciences Iron ore engineering Banded iron formation Mapping techniques Petrology Off line Geology 0105 earth and related environmental sciences |
| Zdroj: | ASEG Extended Abstracts. 2016:1-8 |
| ISSN: | 2202-0586 |
| DOI: | 10.1071/aseg2016ab316 |
| Popis: | Stratigraphy of the Hamersley Province in Western Australia, featuring alternating units of banded iron-formations and shales with contrasting electrical properties in a mostly gently undulating shallow dipping layered geometry, is particularly favourable to airborne time-domain electromagnetic mapping techniques. Manipulated vertical cross-sections of modelled conductivity obtained from laterally constrained 1D inversion of SkyTEM304 data enable the exploration geologist to interpret weathering profiles, shallow dipping stratigraphy and steep structures, all of which are crucial aspects of bedded iron ore deposits genesis models. Five potential interpretation pitfalls have nevertheless been encountered. Occasional obvious artefacts can be present in inverted models but their causative sources should be easily identifiable in the measured channel data. The inverted models coherence is generally compromised when acquisition system terrain clearance cannot be maintained below approximately 80 m. The in-loop setup and processing routines have inherent limitations over steep stratigraphy. Complex stratigraphy geometries can result in off line responses to be artificially incorporated in the 1D inverted conductivity cross-sections. Lastly, lateral interfaces between fresh and altered rocks could easily be misinterpreted as fault contacts. |
| Databáze: | OpenAIRE |
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