If I've correctly interpreted the rhetoric in the stuff I've...

If I've correctly interpreted the rhetoric in the stuff I've read then 500mt might prove to have been a reasonably conservative estimate. It excluded known seams and used a fairly conservative seam width for the seams that were included.

As I understand it the reason it isn't JORC is because the diamond holes that were drilled were a bit far apart - I think holes 4km apart or less are required for coal jorc inferred resource estimates and from memory the two that were used were 5km apart (I'm not hundred percent sure I've got this right).

The coal is also exposed for large lengths around the base of the mountain so this gives them a high level of confidence because its like having a continous series of drill holes around the edge of the resource.