I agree with Clark’s comments. About 14mV/V is my “sulphide threshold” under ideal circumstances.
Cheers Barry From: SEGMIN <[email protected]> On Behalf Of Clark Jorgensen via SEGMIN Sent: Sunday, 24 January 2021 1:20 PM To: S E Geoscience and Exploration via SEGMIN <[email protected]> Cc: Clark Jorgensen <[email protected]> Subject: Re: [SEGMIN] Question for porphyry explorers Sergio, I usually get really excited if I see something that is greater than 15 mV/V over background. That is just based upon looking up several papers where there were good IP surveys that later became mines. But that is assuming you are using the standard Newmont window (0.45 - 1.1 seconds) for a 2 second pulse. Some contractors will deliberately choose earlier time windows so they get bigger anomalies. But of course, like Kim points out, the biggest response is from the outer halo caused by the propylitic zone, so the main mineralized zone will most likely have a weaker response. Clark On 1/23/21 1:49 PM, S E Geoscience and Exploration via SEGMIN wrote: Dear all, Question for all those porphyry explorers: What chargeability value would you consider to be already anomalous for primary mineralization? Of course this value does not only depend on Sulphide-%, but also on its type of occurrence. Thank you in advance for the discussion, Regards -- Sergio Espinosa, Ph.D., P.Geo Director, Geophysics S E Geoscience & Exploration ----------------------- SEGMIN community mailing list service ([email protected] <mailto:[email protected]> ). Change your personal options here: https://lists.geosoft.com/mailman/options/segmin/clark%40bigskygeo.com Colleagues can join here: https://lists.geosoft.com/mailman/listinfo/segmin Archives: https://lists.geosoft.com/mailman/private/segmin/ NOTE that <Reply> will reply to all members of the list. -- Clark Jorgensen Big Sky Geophysics P.O. Box 353 Bozeman, MT 59771 USA +1 (406) 587-6330 office +1 (406) 580-9718 mobile
----------------------- SEGMIN community mailing list service ([email protected]). Change your personal options here: https://lists.geosoft.com/mailman/options/segmin/archive%40mail-archive.com Colleagues can join here: https://lists.geosoft.com/mailman/listinfo/segmin Archives: https://lists.geosoft.com/mailman/private/segmin/ NOTE that <Reply> will reply to all members of the list.
