Aspects of the structural control of fluorite mineralisation in the South Pennine orefield with notes on the mining potential.

The structural geology of the South Pennine Orefield is shown to be composed of an interference pattern of folds related in part to basement features. Folds are shown to have developed with varying trends during and after the deposition of the Carboniferous limestone. It is concluded that some of the faulting, normal and reversed, is genetically related to folding. Columnar calcite is shown to be in many cases earlier than fluorite in the vein-faults and is related, to early phases of movement, whilst fluorite relates to later lateral movements on the same vein-faults. The distribution of fluorspar deposits is documented and is related to the occurrence of open structures at the time of mineralisation. The flow of solutions into the preferentially mineralised anticlines is thought to be controlled by differential pressure release of solutions up through the thin shale cover to the overlying Permo-Triassic unconformity. Some of the major potential fluorite deposits are described in detail and it is concluded that there is sufficient potential to Justify an exploration programme with a view to supplying a second flotation plant in the area. The termsore as used in this thesis is potential ore in the generally accepted senzse of the term. the terms possible ore, probable oreand ore reserves are similarly used to refer to degrees of potentiality and are not used in the normal sense of the terms.