Oaklands now has 121Mt of measured resources, 572Mt indicated and 129Mt of inferred.

Of the 93 drillholes underpinning the resource, Coalworks said all but one intersected the Lanes Shaft seam, with that hole located in a faulted resource exclusion zone.

Coal core logging and geophysics work revealed that the seam contains five separate plies with thicknesses ranging from a minimum of 0.36m in A2 to a maximum of 4.98m in D.

“The interpreted plies are contiguous and relatively continuous but in some areas one or more plies may be absent,” the company said.

“The ply interpretation indicates potential, if required, to selectively mine parts of the Lanes Shaft seam for specific uses.”

Coalworks said the combined drillhole intersections of the Lanes Shaft seam ranged from 2.2m in the southeast of the tenement (EL6861) to 20m in the north.

Roughly 20m above this seam lies the Coreen Creek seam, where intersections ranged from 0.2m to 1.78m thick.

This seam is mainly in the north of the tenement and absent in the southeastern portion, with Coalworks adding it was intersected in the majority of the drillholes.

Testing at Actest laboratories in Newcastle and HRL laboratories in Melbourne determined the Lanes Shaft coal to be a medium to high ash, sub-bituminous coal with low sulfur and medium specific energy contents.

The resource estimate was calculated using minimum section thicknesses of 0.4m, maximum raw ash content of 40% on an air-dried basis and a maximum overburden to coal ratio of 10 billion cubic metres to 1 tonne of coal.

Coal of less than 3000 kilocalories per kilogram was excluded from the resources.

Coal from Lane’s colliery, mined before 1960, and its minor underground workings in the project area was deducted from the total calculated resource.

“We were confident that the measured drilling program would confirm the earlier indicated and inferred resources but we are delighted that the total resource has actually increased,” Coalworks managing director and chief executive Andrew Firek said.

“The increase is due to the continuity and geologically simple nature of the Oaklands coal seams.”

The bankable feasibility study for Oaklands is expected to be completed by the December quarter of 2010, with open cut mining to start in late 2012.

Shares in Coalworks are up 6.5% to 33c this morning.