RE: [ai-geostats] Treatment of gold outliers from belt samples
- Hello Digby,
By sampling problem, I meant aspects of the collection + preparation of the eight samples from the one ton sample. From Kevin's description this all occurs at the laboratory. Thank you Isobel for your clear breakdown of the issues. The geologist in me was trying to draw attention to consideration of the sampling issues as well as the statistical.
Sorry to worry you with my statement, Isobel. I was thinking that this would be the case if the bulk sample was truly homoginised. But as you rightly point out it is unlikey to be so in most crushed gold deposit samples.
From: Digby Millikan [mailto:digbym@...]
Sent: Friday, 13 May 2005 7:34 PM
To: ai-geostats; Reid, David W
Subject: Re: [ai-geostats] Treatment of gold outliers from belt samples
A few questions,
How would you determine the number of samples?
When you say sampling problem, do you mean
problems in the laboratory?
btw Michel David's example of the use of sichel
t-estimator is the use of five samples from Harmony
Mine. He also goes onto discuss pro's and con's
of having 5 samples
arithmetic mean of 5 samples
1195 in-dwt (47.2 gram.metres)
sichel mean of 5 samples
894 in-dwt (35.3 gram metres)
mean derived from 5,170 samples
618 in-dwt (24.4 gram metres)