Ann: Additional Coal Seam Discovered at BBM Coking Coal Mine, page-36

Which is why it is a JORC Estimate. The closer the holes the more accurate the estimate.
The Trial Mine years ago produced results that suggested that JORC Reserves Estimate was pessimistic.
The parameters used for mining were those used in Central QLD and Hunter Valley.
The mining methods are totally different. In Maruwai Basin, small gear is used to clean the top of seam and floor. 30 tonne excavator with flat blade on bucket. So coal losses are less and dilution (ash) inclusion is less.
None of the people preparing any of the reports have ever been involved in mining of coal in Maruwai Basin and therefore all reports are excessively conservative. That is, we can expect more coal and lower ash. All in my opinion of course.
I have been working with Maruwai Basin coal since 2004. It is special.