Continuous mining machines were used as the main colemanite development mining system; drill-blast methods were used for probertite development mining, all access drift mining and all stope mining.
The original mineral of deposition is hypothesized to have been ulexite, a sodium-calcium borate with five molecular waters, but may have originally been deposited as probertite and colemanite.
The orebody continued to alter from probertite to colemanite, developing an envelope of colemanite around an inner core of probertite.
The probertite beds consist of mudstone beds laminated with beds of probertite containing limestone breccia.
The brecciated limestone suspended in probertite indicates an environment of much higher energy.
Nearly all of the fault tension of the orebody was released by deformation of the colemanite, leaving the probertite areas nearly free of faulting.
The slightly acid water easily dissolved probertite and colemanite and reacted with the limestone, gradually removing the limestone, liberating calcium ions and finally neutralizing the solution.
Most bedding structure survived this mineralogical change, indicating that the recrystallization of colemanite proceeded quickly after the dissolution of the probertite, thereby preventing total collapse of the mudstone beds.
Partially dissolved probertite fibers have occasionally been observed penetrating crystals of colemanite at this interface, indicating a wandering focus of dissolution and recrystallization and a solution varying in amount, acidity, and dissolved borate.
The continuing change of probertite to colemanite requires that percolating surface water continue to supply calcium ions and remove sodium ions.
Celestine occurs in colemanite vugs away from the probertite margins and with calcite along the lateral edges of orebody.
This is of interest because the colemanite near the probertite and near areas of clay tends to be of more complex, pointed and radiating habits.