Hi I tackled a similar problem back in the early 80s on a South-African Pb-Zn project where percussion holes had been used to infill a previous diamond drilling campaign. The company allowed me to publish the results. The reference is: Clark, I, 1983: "Reserve estimation -- a geostatistical case study on the comparability of drilling methods" in Surface Mining and Quarrying, Inst. Min. Metall., London, pp.135- 144 and a copy can be read or downloaded from my personal web page at: http://uk.geocities.com/drisobelclark/resume (follow publications link). I also find a variation of cross validation useful where you use the "suspect" results as the "actual values" and the more reliable data set to provide the estimates. This is useful particularly for highlighting bias between the sampling methods. It is discussed in my 1979 APCOM paper "Does Geostatistics Work?" but I have used it often right up to the present for comparing sampling methods, dates of sampling and so on. Hope this helps Isobel http://www.kriging.com
"M. Nur Heriawan" <[EMAIL PROTECTED]> wrote: Dear list, I am doing the structural analysis for Pb-Zn grade in 3D. In the first step, I have used the diamond drill hole (DDH exploration) data. Then I work separately using blast hole (BH) data with number of data is much larger than DDH, but BH data cover the area much less wider in 3D space compare to DDH data. I would like to check the spatial consistency of Pb-Zn grade by statistics and variography analysis between DDH and BH. In this case is interesting also to discuss about change of support as the BH data have much closer spacing compare to DDH data, and BH result sludges/cuttings compare to DDH which result cores for assay data. I am performing the analysis for each rocktypes group (domain). I will be happy if anyone here in the list could share or suggest me any references related to this subject. Thank you for kind help and attention. Regards, --------------- M. Nur Heriawan Earth Resources Exploration Research Group Faculty of Mining and Petroleum Engineering Institut Teknologi Bandung (ITB) Jl. Ganesha 10 Bandung 40132 INDONESIA http://www.mining.itb.ac.id/heriawan + + 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/
