IT TOOK 20 years to plan and bring the world's biggest deep mine complex at Selby into production.

But today the three pits which are left at Riccall, Stillingfleet and Wistow are riddled with geological faulting which has fragmented the Barnsley coal seam.

Poor geology has already led to the closure of Whitemoor mine in 1996 followed by the shutdown of North Selby mine at Escrick the following year.

Today UK Coal bosses revealed the geological problems that continue to plague the coalfield.

Miners at Riccall are having to deal with inflows of water which have flooded roadways as well as significant faulting in the coal seams.

A UK Coal report says that coal reserves are restricted to narrow areas bounded by substantial faulting, with the coal seam splitting and deteriorating to the south.

The company concludes that the coal reserves at Riccall are generally "high risk" due to the size of the faults and uncertainty of the seam thickness.

At Stillingfleet mine there is a large area of coal to the west of the pit - but again this is classified as "high risk", due to the proximity of the water-bearing permian strata and significant faulting.

Most of Stillingfleet's reserves are to the north, but UK Coal says that access to this coal would be very difficult and its quality is unproven.

There are also major problems at Wistow mine. UK Coal says that there are significant areas of coal to the north of Cawood and to the south of Thorpe Hall but access would be difficult and would require additional exploration for structural security.

The company also quotes experts from International Mining Consultants (IMC), an independent company, which support UK Coal's case.

The IMC report said "It is clearly evident that the current plans at Selby generate significant financial losses, with little option for changing the situation.

"As the mines are totally dependent upon each other, the mine with the shortest life dictates the life of the others.

"Set against the background of the financial performance of the past three years at Selby, together with low proceeds, it is unlikely that any major capital development would result in an acceptable return on investment."

The IMC report also says that other coal seams at Selby do not approach the consistent thickness and quality of the Barnsley seam and are much less attractive to mine.

UK Coal says that the complex continues to incur heavy losses despite £94 million of investment in new equipment since 1995.

Production has declined rapidly from 12 million tonnes of coal in 1997 to 4.5 million tonnes last year.

The company says the complex has no prospect of being viable as an ongoing business.

Updated: 15:28 Tuesday, July 16, 2002