LAND-BASED VECTOR MAGNETIC SURVEY OF A BIF-HOSTED IRON ORE DEPOSIT, MARY RIVER, BAFFIN ISLAND, NUNAVUT

Banded iron formations (BIFs) are iron oxide- and silica-rich chemical sedimentary rocks and the principal source of high-grade (HG) iron ore. Magnetic survey methods are commonly applied in the exploration for BIF-hosted iron ore deposits but the interpretation of total magnetic intensity (TMI) dat...

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Bibliographic Details
Main Author: Inozemtsev, Ilya
Other Authors: Boyce, Joe, Geography and Earth Sciences
Format: Thesis
Language:English
Published: 2015
Subjects:
Online Access:http://hdl.handle.net/11375/17212
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spelling ftmcmaster:oai:macsphere.mcmaster.ca:11375/17212 2023-05-15T15:35:25+02:00 LAND-BASED VECTOR MAGNETIC SURVEY OF A BIF-HOSTED IRON ORE DEPOSIT, MARY RIVER, BAFFIN ISLAND, NUNAVUT LAND-BASED VECTOR MAGNETIC SURVEY OF BIF-HOSTED IRON ORE Inozemtsev, Ilya Boyce, Joe Geography and Earth Sciences 2015 http://hdl.handle.net/11375/17212 en eng http://hdl.handle.net/11375/17212 Ground-based vector magnetic survey fluxgate magnetometer iron ore deposit Thesis 2015 ftmcmaster 2022-03-22T21:12:51Z Banded iron formations (BIFs) are iron oxide- and silica-rich chemical sedimentary rocks and the principal source of high-grade (HG) iron ore. Magnetic survey methods are commonly applied in the exploration for BIF-hosted iron ore deposits but the interpretation of total magnetic intensity (TMI) data is often complicated by the presence of strong remanent magnetization and anisotropy of magnetic susceptibility (AMS). This study evaluated a tri-axial fluxgate vector magnetometer system for ground-based high-resolution mapping of BIF-hosted HG iron ore deposits at a 16 ha site near Mary River, Baffin Island. Magnetometer orientation was measured using a MEMS (Micro Electro-Mechanical System) accelerometer and dual D-GPS receivers. 12-oriented block samples were collected for analysis of rock magnetic properties and supplemented with outcrop measurements using a hand-held susceptibility probe. The large (3 Gauss) dynamic range of the tri-axial vector magnetometer permitted mapping of HG magnetite ore zones, with TMI in excess of 400,000 nT. A 20 m-wide W-E trending HG zone and a narrow (<10 m) BIF zone were identified in RMV maps with distinctive dipole signatures. Within the HG zone a northwest-southeast oriented magnetic fabric was defined by linear magnetic lows that offset the strike of the HG ore zone and were interpreted as brittle faults or shear zones. The RMV orientation indicated the presence of strong bedding parallel magnetization, while its signal amplitude showed a wide variation between ore types and provided basis for ore grade differentiation. Paleomagnetic measurements revealed high Q ratios for hematite ores and strong AMS for BIF. The results from Mary River demonstrate that remanence and AMS effects are important in BIF-hosted iron ores and cannot be neglected in magnetic interpretation and inversion modelling of magnetic source bodies. Thesis Master of Science (MSc) Thesis Baffin Island Baffin Nunavut MacSphere (McMaster University) Nunavut Baffin Island
institution Open Polar
collection MacSphere (McMaster University)
op_collection_id ftmcmaster
language English
topic Ground-based vector magnetic survey
fluxgate magnetometer
iron ore deposit
spellingShingle Ground-based vector magnetic survey
fluxgate magnetometer
iron ore deposit
Inozemtsev, Ilya
LAND-BASED VECTOR MAGNETIC SURVEY OF A BIF-HOSTED IRON ORE DEPOSIT, MARY RIVER, BAFFIN ISLAND, NUNAVUT
topic_facet Ground-based vector magnetic survey
fluxgate magnetometer
iron ore deposit
description Banded iron formations (BIFs) are iron oxide- and silica-rich chemical sedimentary rocks and the principal source of high-grade (HG) iron ore. Magnetic survey methods are commonly applied in the exploration for BIF-hosted iron ore deposits but the interpretation of total magnetic intensity (TMI) data is often complicated by the presence of strong remanent magnetization and anisotropy of magnetic susceptibility (AMS). This study evaluated a tri-axial fluxgate vector magnetometer system for ground-based high-resolution mapping of BIF-hosted HG iron ore deposits at a 16 ha site near Mary River, Baffin Island. Magnetometer orientation was measured using a MEMS (Micro Electro-Mechanical System) accelerometer and dual D-GPS receivers. 12-oriented block samples were collected for analysis of rock magnetic properties and supplemented with outcrop measurements using a hand-held susceptibility probe. The large (3 Gauss) dynamic range of the tri-axial vector magnetometer permitted mapping of HG magnetite ore zones, with TMI in excess of 400,000 nT. A 20 m-wide W-E trending HG zone and a narrow (<10 m) BIF zone were identified in RMV maps with distinctive dipole signatures. Within the HG zone a northwest-southeast oriented magnetic fabric was defined by linear magnetic lows that offset the strike of the HG ore zone and were interpreted as brittle faults or shear zones. The RMV orientation indicated the presence of strong bedding parallel magnetization, while its signal amplitude showed a wide variation between ore types and provided basis for ore grade differentiation. Paleomagnetic measurements revealed high Q ratios for hematite ores and strong AMS for BIF. The results from Mary River demonstrate that remanence and AMS effects are important in BIF-hosted iron ores and cannot be neglected in magnetic interpretation and inversion modelling of magnetic source bodies. Thesis Master of Science (MSc)
author2 Boyce, Joe
Geography and Earth Sciences
format Thesis
author Inozemtsev, Ilya
author_facet Inozemtsev, Ilya
author_sort Inozemtsev, Ilya
title LAND-BASED VECTOR MAGNETIC SURVEY OF A BIF-HOSTED IRON ORE DEPOSIT, MARY RIVER, BAFFIN ISLAND, NUNAVUT
title_short LAND-BASED VECTOR MAGNETIC SURVEY OF A BIF-HOSTED IRON ORE DEPOSIT, MARY RIVER, BAFFIN ISLAND, NUNAVUT
title_full LAND-BASED VECTOR MAGNETIC SURVEY OF A BIF-HOSTED IRON ORE DEPOSIT, MARY RIVER, BAFFIN ISLAND, NUNAVUT
title_fullStr LAND-BASED VECTOR MAGNETIC SURVEY OF A BIF-HOSTED IRON ORE DEPOSIT, MARY RIVER, BAFFIN ISLAND, NUNAVUT
title_full_unstemmed LAND-BASED VECTOR MAGNETIC SURVEY OF A BIF-HOSTED IRON ORE DEPOSIT, MARY RIVER, BAFFIN ISLAND, NUNAVUT
title_sort land-based vector magnetic survey of a bif-hosted iron ore deposit, mary river, baffin island, nunavut
publishDate 2015
url http://hdl.handle.net/11375/17212
geographic Nunavut
Baffin Island
geographic_facet Nunavut
Baffin Island
genre Baffin Island
Baffin
Nunavut
genre_facet Baffin Island
Baffin
Nunavut
op_relation http://hdl.handle.net/11375/17212
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