Authors / CoAuthors
Spies, B.R.
Abstract
A series of transient electromagnetic (TEM) scale-model studies of the Elura zinc-lead-silver deposit near Cobar, NSW, has been carried out. The results are generalised inasmuch as they are not restricted to the Elura deposit, but may be applied to other pipe-like bodies. A model of Elura was cast out of typemetal into a graphite mould, which simulated a conductive host rock. For both one-loop and two-loop geometries the response of the body at early times is masked by the host rock, and the response of the body at late times is two to three times background. By studying the fall-off of response with depth of burial, it was found that there is an optimum time range in which a conductive body can be detected. This time range depends on the conductivity and size of the body and the conductivity of the host rock. The optimum loop size for detecting a body in a resistive environment is slightly larger than the size of the body in plan. If the body is contained in a conductive host rock, then a smaller loop will minimise coupling with the host rock and will enable detection of the body over a wider time range. However the smaller loop also emphasises lateral inhomogeneities in the overburden. The response obtained with a two-loop system is more complex than for a coincident-loop geometry, and can be positive or negative in sign, depending on the sample time, loop separation, depth of burial of body, and host-rock conductivity. For loop separations less than the depth of the body, the two-loop response closely resembles the one-loop response.
Product Type
document
eCat Id
81031
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
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Australia
Keywords
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- GA PublicationJournal
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- NSW
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_External
Publication Date
1980-01-01T00:00:00
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Topic Category
geoscientificInformation
Series Information
BMR Journal of Australian Geology and Geophysics 5:2:77-85
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Unknown
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Extents
[-31.5, -31.0, 145.5, 146.0]
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