Geophysical investigation of chromite-bearing ultrabasic rocks in the Baltasound-Hagdale area, Unst, Shetland Islands

Johnson, C.E.; Smith, C.G.; Fortey, N.J.. 1980 Geophysical investigation of chromite-bearing ultrabasic rocks in the Baltasound-Hagdale area, Unst, Shetland Islands. Institute of Geological Sciences, 79pp. (WF/MR/80/035) (Unpublished)

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Abstract/Summary

Economic deposits of chromite were discovered in Unst, Shetland Islands in the early part of the nineteenth century and extraction continuedi ntermittentlyu ntil exhaustiono f the known near-surface deposits in 1945. Since it is likely that further comparable deposits exist at shallow depth, detailed geophysical smeys employing 2 magnetic and electrical methods were carried out over ? km of the area of known mineralisationt o test the feasabilityo f detectinga nd delineatingt hem. Seven of 16 small positive gravity arumaJ.ie&se tested by shallow boreholes but only two were attributed to chromite concentrations.T he gravity anomaliesa t the other borehole sites remain unexplained; they may be due to unidentified variations in bedrock density at depth; they may be of weathering and the thickness of in overburden thickness.

Item Type:	Publication - Report
Programmes:	BGS Programmes > Other
Funders/Sponsors:	Department of Industry
Additional Information. Not used in RCUK Gateway to Research.:	This item has been internally reviewed but not externally peer-reviewed
NORA Subject Terms:	Earth Sciences
Date made live:	02 Nov 2010 11:38 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/11887

Item Type:

Publication - Report

Programmes:

BGS Programmes > Other

Funders/Sponsors:

Department of Industry

Additional Information. Not used in RCUK Gateway to Research.:

This item has been internally reviewed but not externally peer-reviewed

NORA Subject Terms:

Earth Sciences

Date made live:

02 Nov 2010 11:38 +0 (UTC)