Isobel While your comment "a block is not even estimated unless it is pretty adequately known" is valid, practised on many sites, and useful eg used to justify more drilling, it is not always practical. Some software such as Whittle cannot cope with unestimated blocks, so we estimate a grade for them (eg by using larger searches), but they are classified as lower confidence. If not estimated, there is still a need to have some statement of this resource.
Related to this, is what I term the 'salt& pepper' problem. If blocks are assigned a classification based on individual parameters, it can result in a mosaic of Inferred, Indicated and Measured blocks. While this may be absolutely, mathematically, correct, it too is impractical (for us anyway). Hence our strategy of making a judgement based on many parameters, and applying the classification to a 'large' contiguous area. I am very pleased to see this topic raised as some guidelines are long overdue. Jim ph 08 9327 2263 fax 08 9327 2294 -----Original Message----- From: Isobel Clark [mailto:[EMAIL PROTECTED]] Sent: Wednesday, 27, February 2002 12:32 To: Farquhar, James (HI) Cc: [EMAIL PROTECTED]; Bill Shaw Subject: RE: AI-GEOSTATS: What are appropriate measures of reliability for Mineral Resource and Ore Reserve estimates? Jim I totally agree with your principles. The main difference, in operation not philosophy, is that most (good?) practitioners include 'all of the above' before getting to a classification stage. For example, the selection of which blocks to estimate in the first place is done on the basis of all existing geological knowledge plus assumptions about continuity etc. So, a block is not even estimated unless it is pretty adequately known anyway. The use of a single criterion to distinguish the line between measured and indicated resources is almost a formality and probably depends more on the target audience than any other motivation. Isobel __________________________________________________ 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 ---------------------------------------------- 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
