Determination of near-surface, crustal and lithospheric structures in the Canadian Precambrian Shield using time-domain electromagnetic and magnetotelluric methods
Two electromagnetic methods were used to analyse the geoelectric structure of the subsurface of regions of the Precambrian Shield in Canada: the magnetotelluric (MT) and time-domain electromagnetic (TEM) methods. Magnetotelluric soundings were made at 60 sites in the southwestern Northwest Territori...
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ftunivmanitoba:oai:mspace.lib.umanitoba.ca:1993/1961 2023-06-18T03:40:39+02:00 Determination of near-surface, crustal and lithospheric structures in the Canadian Precambrian Shield using time-domain electromagnetic and magnetotelluric methods Wu, Xianghong 2001-08-01T00:00:00Z 18675344 bytes 184 bytes application/pdf text/plain http://hdl.handle.net/1993/1961 eng eng http://hdl.handle.net/1993/1961 open access doctoral thesis 2001 ftunivmanitoba 2023-06-04T17:44:25Z Two electromagnetic methods were used to analyse the geoelectric structure of the subsurface of regions of the Precambrian Shield in Canada: the magnetotelluric (MT) and time-domain electromagnetic (TEM) methods. Magnetotelluric soundings were made at 60 sites in the southwestern Northwest Territories, Canada, along the LITHOPROBE SNORCLE Transect Corridor 1 and 1A, in the summer of 1996. The sites are located in southwestern Northwest Territories, Canada, between latitudes 60-65N and longitudes 110-125W, and cross the Archean Slave Province, the Proterozoic Buffalo Head, Great Bear Magmatic Arc, Hottah, Fort Simpson and Nahanni terranes, and the Great Slave Lake Shear Zone. Phanerozoic sedimentary rocks overlie the Proterozoic terranes. The main object of this project is to map the fracture zones and fresh/saline water interface in Precambrian granitic rocks using the surface TEM method. The TEM surveys were completed at Sites B, D, URL and A. A GEONICS PROTEM47 system with a 100 m transmitter loop wasused. The data were collected for receiver offsets ranging from 0-280 m on four sides of transmitter loop. Analysis of the TEM and borehole log data indicates a basic three-layer structure: a thin conductive surface layer, a thick resistive second layer with an embedded conductive layer at some stations, and a conductive bottom layer. The results of this study show the TEM method can be used to investigate the fracture zones and groundwater salinity distribution in the Precambrian granitic rocks and contribute to site investigations for nuclear waste deposit. The TEM study in the Lac du Bonnet Batholith was successful in demonstrating the potential of the TEM methods in mapping groundwater salinity in granitic batholith. The PROTEM47 instrument, in combination with a 100 m transmitter loop, provides a suitable TEM system for mapping the resistivity structure of the Lac du Bonnet batholith down to a depth of 300-400 m. For deeper penetration and more accurate results in areas of fracture zones, other TEM systems ... Doctoral or Postdoctoral Thesis Fort Simpson Great Slave Lake Northwest Territories MSpace at the University of Manitoba Buffalo Head ENVELOPE(173.225,173.225,52.908,52.908) Canada Fort Simpson ENVELOPE(-121.320,-121.320,61.808,61.808) Great Slave Lake ENVELOPE(-114.001,-114.001,61.500,61.500) Northwest Territories |
institution |
Open Polar |
collection |
MSpace at the University of Manitoba |
op_collection_id |
ftunivmanitoba |
language |
English |
description |
Two electromagnetic methods were used to analyse the geoelectric structure of the subsurface of regions of the Precambrian Shield in Canada: the magnetotelluric (MT) and time-domain electromagnetic (TEM) methods. Magnetotelluric soundings were made at 60 sites in the southwestern Northwest Territories, Canada, along the LITHOPROBE SNORCLE Transect Corridor 1 and 1A, in the summer of 1996. The sites are located in southwestern Northwest Territories, Canada, between latitudes 60-65N and longitudes 110-125W, and cross the Archean Slave Province, the Proterozoic Buffalo Head, Great Bear Magmatic Arc, Hottah, Fort Simpson and Nahanni terranes, and the Great Slave Lake Shear Zone. Phanerozoic sedimentary rocks overlie the Proterozoic terranes. The main object of this project is to map the fracture zones and fresh/saline water interface in Precambrian granitic rocks using the surface TEM method. The TEM surveys were completed at Sites B, D, URL and A. A GEONICS PROTEM47 system with a 100 m transmitter loop wasused. The data were collected for receiver offsets ranging from 0-280 m on four sides of transmitter loop. Analysis of the TEM and borehole log data indicates a basic three-layer structure: a thin conductive surface layer, a thick resistive second layer with an embedded conductive layer at some stations, and a conductive bottom layer. The results of this study show the TEM method can be used to investigate the fracture zones and groundwater salinity distribution in the Precambrian granitic rocks and contribute to site investigations for nuclear waste deposit. The TEM study in the Lac du Bonnet Batholith was successful in demonstrating the potential of the TEM methods in mapping groundwater salinity in granitic batholith. The PROTEM47 instrument, in combination with a 100 m transmitter loop, provides a suitable TEM system for mapping the resistivity structure of the Lac du Bonnet batholith down to a depth of 300-400 m. For deeper penetration and more accurate results in areas of fracture zones, other TEM systems ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Wu, Xianghong |
spellingShingle |
Wu, Xianghong Determination of near-surface, crustal and lithospheric structures in the Canadian Precambrian Shield using time-domain electromagnetic and magnetotelluric methods |
author_facet |
Wu, Xianghong |
author_sort |
Wu, Xianghong |
title |
Determination of near-surface, crustal and lithospheric structures in the Canadian Precambrian Shield using time-domain electromagnetic and magnetotelluric methods |
title_short |
Determination of near-surface, crustal and lithospheric structures in the Canadian Precambrian Shield using time-domain electromagnetic and magnetotelluric methods |
title_full |
Determination of near-surface, crustal and lithospheric structures in the Canadian Precambrian Shield using time-domain electromagnetic and magnetotelluric methods |
title_fullStr |
Determination of near-surface, crustal and lithospheric structures in the Canadian Precambrian Shield using time-domain electromagnetic and magnetotelluric methods |
title_full_unstemmed |
Determination of near-surface, crustal and lithospheric structures in the Canadian Precambrian Shield using time-domain electromagnetic and magnetotelluric methods |
title_sort |
determination of near-surface, crustal and lithospheric structures in the canadian precambrian shield using time-domain electromagnetic and magnetotelluric methods |
publishDate |
2001 |
url |
http://hdl.handle.net/1993/1961 |
long_lat |
ENVELOPE(173.225,173.225,52.908,52.908) ENVELOPE(-121.320,-121.320,61.808,61.808) ENVELOPE(-114.001,-114.001,61.500,61.500) |
geographic |
Buffalo Head Canada Fort Simpson Great Slave Lake Northwest Territories |
geographic_facet |
Buffalo Head Canada Fort Simpson Great Slave Lake Northwest Territories |
genre |
Fort Simpson Great Slave Lake Northwest Territories |
genre_facet |
Fort Simpson Great Slave Lake Northwest Territories |
op_relation |
http://hdl.handle.net/1993/1961 |
op_rights |
open access |
_version_ |
1769005881620430848 |