Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Application of 3D magnetic amplitude inversion to iron oxide-copper-gold deposits at low magnetic latitudes; a case study from Carajas mineral province, Brazil

Marcelo Leao-Santos, Yaoguo Li and Roberto Moraes
Application of 3D magnetic amplitude inversion to iron oxide-copper-gold deposits at low magnetic latitudes; a case study from Carajas mineral province, Brazil
Geophysics (March 2015) 80 (2): B13-B22

Abstract

Strong hydrothermal alteration modifies rock physical properties in iron oxide-copper-gold deposits (IOCGs) and may result in characteristic signatures detectable in geophysical surveys. Magnetic data are commonly used in characterizing orebodies, and 3D inversions are often used to assist in interpretations. In areas with strong remanence and self-demagnetization, the total magnetization can have directions different from the inducing field direction. This deviation precludes the use of traditional inversion methods. Magnetic amplitude inversion offers one solution to this challenge because the amplitude data are weakly dependent on the magnetization direction. In addition, the low magnetic latitude also imposes difficulty in amplitude data calculation due to the instability in the component conversion in the wavenumber domain. To formulate a practical approach, we present a case study on applying the magnetic amplitude inversion to the Furnas southeast IOCG deposit at the low magnetic latitude in Carajas Mineral Province, Brazil, and demonstrate that the approach can reliably recover an interpretable distribution of effective magnetic susceptibility and identify massive magnetite from hydrothermal alterations associated with the high-grade ore.


ISSN: 0016-8033
EISSN: 1942-2156
Coden: GPYSA7
Serial Title: Geophysics
Serial Volume: 80
Serial Issue: 2
Title: Application of 3D magnetic amplitude inversion to iron oxide-copper-gold deposits at low magnetic latitudes; a case study from Carajas mineral province, Brazil
Affiliation: Vale, Department of Exploration and Mineral Projects, Belo Horizonte, Brazil
Pages: B13-B22
Published: 201503
Text Language: English
Publisher: Society of Exploration Geophysicists, Tulsa, OK, United States
References: 30
Accession Number: 2015-051952
Categories: Applied geophysicsEconomic geology, geology of ore deposits
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, sketch map
S07°45'00" - S05°30'00", W51°04'60" - W49°00'00"
Secondary Affiliation: Colorado School of Mines, USA, United StatesUniversidade de Brasilia, BRA, Brazil
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by Society of Exploration Geophysicists, Tulsa, OK, United States
Update Code: 201524
Close Modal

or Create an Account

Close Modal
Close Modal