Multi-element geochemical studies in the Southern Pennine Orefield and north Leicestershire, England.

Stream sediment surveys were undertaken south of the Derbyshire limestone mass and north Leicestershire. The samples were analysed for a wide range of elements using a direct reading spectrometer. The analytical results were interpreted with the aid of computer-orientated techniques particularly, univariate and multivariate statistical methods. The univariate method used involved breaking down complex elemental distributions into discrete populations. The separated populations were then related to various causitive factors of the geological environment. The multivariate methods of cluster and principal components analyses were extensively used. From the application of Q-mode cluster analysis several criteria were deduced that may be useful in the interpretation of multi-element geochemical data. The results of the surreys showed some distinct elemental and sample associations that can be related to the effects of the secondary environment, bedrock and mineralization. Several areas were found deserving further attention. The Tickow Lane occurrence near Shepshed in Leicestershire showed a conspicuous enrichment of lead and molybdenum within the Triassic sandstones. The highest concentrations of lead and molybdenum were found in the grey sandstone below a dark brown layer. The apparent logarithmic decay pattern of certain elements across the stratigraphy and the clamming effect of finer sediments could imply a general downward percolation of metalliferous, solutions. Primary dispersion studies were also conducted on the limestone wallrocks adjacent to lead-zinc deposits in Derbyshire. Mineralogical, geochemical and thermoluminescence aureoles were determined from wallrock samples from five localities. The results showed very limited primary dispersion aureoles of quartz, fluorite and the wide range of elements determined. Natural, irradiated and deteriorated thermo- luminescence patterns were inconsistent and no diagnostic features were noted to indicate the presence of mineralized veins.