AI-GEOSTATS: Spatial dependence and sampling variograms

[JW]

Hello Raimon,   In mineral exploration, testing for spatial dependence always makes sense, in particular if the extraneous measurement variance (that nugget effect!) has been estimated in a meaningful manner. Examine the test results for gold and silver of the Cerratepe bulk sampling program where pairs of interleaved primary samples were selected from each round and a reliable estimate for the measurement variance was obtained http://ai-geostats.jrc.it/documents/JW_Merks/.   Alternatively, it may be necessary to prepare and assay second halves of a set of core samples to obtain a realistic estimate for the measurement variance. An example of how to take this measurement variance into account can be found in Borehole Statistics with Spreadsheet Software. This reviewed paper is posted on my website at http://www.geostatscam.com.   Kind regards, Jan W Merks   ----- Original Message ----- From: Raimon Tolosana To: ai-geostats@jrc.it Sent: Saturday, July 22, 2006 10:30 AM Subject: Re: AI-GEOSTATS: KWBP Test Program Dear list, this situation posed by Mr.Merks, in which spatial dependence is not strong enough as to be useful for geostatiscs, might be rather common. I'd like to ask to the list, what kind of estimation of reserves should be done in this case? In the absence of spatial dependence, classical statistics should apply: therefore, shall we estimate the mean value of ore content in the "deposit" by the arithmetic mean of the samples? And attach an error to it, in the fashion of the standard error of the mean (something like the variance of the sample divided by number of data used)? Or did I grossly misunderstand something in the discussion, with so much bogus-hocus-pocus and 5-line sentences? thanks for the patience Raimon Tolosana En/na JW ha escrit: > > Hello Readers, > >  > > More talk and not test. I want to know what the KWBP methodology does > with the Bre-X data. Is that too much to ask? > >  > > Kind regards, > > Jan W Merks + + To post a message to the list, send it to ai-geostats@jrc.it + To unsubscribe, send email to majordomo@ jrc.it with no subject and "unsubscribe ai-geostats" in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list + As a general service to list users, please remember to post a summary of any useful responses to your questions. + Support to the forum can be found at http://www.ai-geostats.org/