I'm not sure that any one parameter can provide the measure. Resources can be classified on
1. drill data and support (quality of the drill logs, sampling, assays, standards and duplicates); 2. drill hole spacing (adequacy for the resource type, eg less than variogram major range); 3. structural complexity; 4. interpretation quality, strings and triangulations (how well do the geology strings fit the drilling and the regional geology); 5. mineralisation type 6. continuity of grade; 7. anomalies (inconsistent or contradictory data); 8. statistics results eg variance, CV, nugget effect, short range structures, neighbourhood test results; 9. estimation method; 10. run flag; 11. kriging variance (relatively high or low within the strand); 12. tonnage / metre intersected in cases of sparse drilling; 13. confidence intervals (via gaussian transforms); 14. conditional simulation results. And there are probably more. Our classification is based on a (subjective?) assessment of the first 10 above. And we also recognise that one poor measure can destroy confidence eg no amount of good interpretation or statistics can make up for poor sampling - the deposit will have a low classification. Hope this makes sense - and as Clint Eastwood says 'works for me!' Jim ph 08 9327 2263 fax 08 9327 2294 -----Original Message----- From: Isobel Clark [mailto:[EMAIL PROTECTED]] Sent: Wednesday, 27, February 2002 1:40 To: Bill Shaw Cc: [EMAIL PROTECTED] Subject: Re: AI-GEOSTATS: What are appropriate measures of reliability for Mineral Resource and Ore Reserve estimates? Bill There are several presentations being given this week at the APCOM in Phoenix. You might want to look at the proceedings and check through those. One of the papers I have heard so far compares three criteria and shows how they affect a particular case study. The three are a weighted distance criterion, a kriging variance and an information measure. In this particular case, kriging variance came out bottom. Pity, because that's what I use! Isobel Isobel Clark http://uk.geocities.com/drisobelclark __________________________________________________ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- * To post a message to the list, send it to [EMAIL PROTECTED] * As a general service to the users, please remember to post a summary of any useful responses to your questions. * To unsubscribe, send an email to [EMAIL PROTECTED] with no subject and "unsubscribe ai-geostats" followed by "end" on the next line in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list * Support to the list is provided at http://www.ai-geostats.org ---------------------------------------------- This email (including all attachments) may be confidential. If you are not the intended recipient, you must not use the information contained in it. If you have received this email in error, please delete the email and notify the sender. -- * To post a message to the list, send it to [EMAIL PROTECTED] * As a general service to the users, please remember to post a summary of any useful responses to your questions. * To unsubscribe, send an email to [EMAIL PROTECTED] with no subject and "unsubscribe ai-geostats" followed by "end" on the next line in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list * Support to the list is provided at http://www.ai-geostats.org
