BCGS GeoFile 2011-06

By G.J. Simandl, S. Paradis, R. Fajber and N. Rogers

http://www.empr.gov.bc.ca/Mining/Geoscience/PublicationsCatalogue/GeoFiles/Pages/2011-6.aspx

Carbonate-hosted nonsulphide base metal mineralization is derived from sulphide deposits by supergene processes. In the field such occurrences can be described as ‘red ores’ or ‘white ores’. Red ores consist mainly of Fe-oxyhydroxides: goethite, hematite, and hemimorphite, as well as minor smithsonite, hydrozincite and cerussite (+/- vestiges of galena ). They are difficult to distinguish macroscopically from barren gossans. White ores consist mainly of hemimorphite, smithsonite, and hydrozincite, as well as minor Fe-oxyhydroxides. In some cases white ores are difficult to distinguish from the enclosing carbonate host rock.

Samples fromthe red and white nonsulphide mineralization were analysed first using portable hand-held X-Ray Fluorescence (XRF) spectrometry and secondlyusing laboratory ICP-MS/ICP-ES methods (following lithium metaborate fusion).

Comparison between the methodsindicates that the portable hand-held XRF is a useful field tool in exploration for carbonate-hosted nonsulphidemineralization. The instrument is able to distinguish between barren, moderately mineralized and high grademineralized samples; making it useful where rapid decisions are needed (on a drill site, during helicopter supported geological work, or for semi-quantitative verification of ore gradesat a mine site). Our tests also indicate that currently available portable hand-held XRF analysis is not a substitute for analytical laboratory methods (such as ICP-MS/ICP-ES or assays).

Property File database now features more than 26,800 documents online!

During 2010 Property File, a collection of over 63,000 unique industry documents and maps, continued to grow. Recent Property File donations were made by Andre Panteleyev, Tom Schroeter, Ken Dawson and the estate of W.G. Hainsworth. As of January 2011, 26,882 property file documents were available online, including 396 Falconbridge, 1924 Cyprus-Anvil, 304 Chevron, 479 Placer Dome, 1328 Rimfire, 2969 Mines Plans, 5740 Tom Schroeter project files and 13732 Library items. These are retrieved through the Property File Search application or through links from MINFILE.

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Most provincial geoscience data can be easily accessed over the internet in map format at:

http://www.mapplace.ca/ and through various thematic pages at www.empr.gov.bc.ca/Mining/Geoscience

Printed BC Geological Survey geoscience publications are available from Crown Publications Inc.

Tel: 250-387-6409 Fax: 250-387-1120

Email: crown@pinc.com Website: www.crownpub.bc.ca/

Questions or to update your contact info please contact the BC Geological Survey:

Email: Geological.Survey@gov.bc.ca Tel: 250-952-0372 Fax: 250-952-0381

BC Geological Survey

British Columbia Ministry of Forest, Mines and Lands

Mines and Mineral Resources Division

Release Notification 2011-04

February 22, 2011