HR: 16:30h
AN: GP34A-03    [Abstracts]
TI: A Magnetotelluric Survey of the Kaapvaal Craton and its surroundings: The SAMTEX Experiment
AU: Jones, A G
EM: alan@cp.dias.ie
AF: Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin, 2 Ireland
AU: Evans, R
EM: revans@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Geology and Geophysics, Woods Hole, MA 02543 United States
AU: * Garcia, X
EM: xavi@cp.dias.ie
AF: Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin, 2 Ireland
AU: Hamilton, M
EM: mh@cp.dias.ie
AF: Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin, 2 Ireland
AU: Hamilton, M
EM: mh@cp.dias.ie
AF: The University of the Witwatersrand, School of Geosciences, Private Bag 3, Johannesburg, 2050 South Africa
AU: Evans, S
EM: shane.evans@debeersgroup.com
AF: De Beers, De Beers Group Services, Private Bag X01, Southdale, 2135 South Africa
AU: Fourie, S
EM: stoffel@geoscience.org.za
AF: Council for Geoscience, 280 Pretoria Street, Silverton, Pretoria, 12 South Africa
AU: Mountford, A
EM: Andy.Mountford@riotinto.com
AF: Rio Tinto, Rio Tinto Mineral Exploration Inc., PO Box 695, 7th Floor Castlemead, Lower Castle Street, Bristol, BS99 1FS United Kingdom
AU: Spratt, J
EM: jsp@cp.dias.ie
AF: Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin, 2 Ireland
AU: Chave, A D
EM: alan@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Geology and Geophysics, Woods Hole, MA 02543 United States
AB: Initiated in 2003, the Southern African Magnetotelluric (MT) Experiment (SAMTEX) is being conducted by a consortium comprising academic, industry and government partners representing five countries from around the world. When completed, it will be the largest land-based MT study yet performed, and to date includes the collection of MT sounding data with broadband (~0.002 s to ~6000 s) magnetotelluric (BBMT) instruments at more than 330 sites. Long period (20 s to ~10,000 s) magnetotelluric (LMT) instruments were installed at approximately a third of the sites to enhance depth penetration. The total length of the profiles is well over 5,000 km, with a BBMT station spacing of nominally 20 km, and an LMT spacing of 60 km (every third BBMT site) and includes a wide variety of Archean and Proterozoic terrains. The survey is being conducted in order to gain insight into the electrical structure of the crust and lithospheric mantle beneath the cratons of southern Africa and their surrounding terranes, and from that knowledge to infer Archean and Proterozoic processes of formation and deformation. The main profile of the survey, traversing the Kaapvaal craton from SW-NE, is largely coincident with a seismic experiment (SASE) and it is expected that the combined results of SASE and SAMTEX, together with the superb geochemical knowledge, should complement each other and add considerably to our understanding of southern Africa. Here we present details of the experiment and preliminary models from the ~1300 km long profile collected during the first phase of the experiment across the Kaapvaal craton in South Africa.
DE: 0925 Magnetic and electrical methods (5109)
DE: 8031 Rheology: crust and lithosphere (8159)
DE: 8103 Continental cratons
DE: 8125 Evolution of the Earth (0325)
DE: 9623 Archean
SC: Geomagnetism and Paleomagnetism [GP]
MN: Fall Meeting 2005