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 (WF/MR/80/035) (Unpublished)Before downloading, please read NORA policies.
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:||Report (UNSPECIFIED)|
|Programmes:||BGS Programmes > Other|
|Funders/Sponsors:||Department of Industry|
|Additional Information:||This item has been internally reviewed but not externally peer-reviewed|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||02 Nov 2010 11:38|
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