ECONOMIC GEOLOGY IN EUROPE AND BEYOND .2. REPORT OF PROCEEDINGS - ABSTRACTS

Plant provided an excellent introduction to the conference by describi ng a comprehensive multidisciplinary project that is currently being u ndertaken by the British Geological Survey (BGS) to study both the hyd rocarbon and metalliferous resource potential of the Cheshire Basin. T he basin contains the thickest sediment fill of the Permo-Triassic bas ins in the United Kingdom. Small-scale Cu mineralization at surface di splays many characteristics of major strata-bound copper deposits, suc h as the Kupferschiefer and the Zambian Copper belt-for instance, post -diagenetic emplacement in rift basins and the presence of thick, perm eable, coarse clastic facies in the footwall of the Cu-bearing zone. T his illustrates the potential for the presence of undiscovered mineral deposits of much greater size at depth and offers the opportunity for detailed study and characterization to aid exploration for such depos its. Details were given of the key topics investigated and the respect ive findings to date. The study, which has involved more than 25 scien tists over a three-year period, has considered such important areas as diagenetic history, hydrogeology, burial and thermal history, provena nce studies, structural basin analysis and resources and has also incl uded the development of an expert system. The presentation outlined th e wide range of specialist data and expertise that the BGS is able to provide for such a project and the scientific developments that can re sult from a structured and integrated approach of this nature. Phillip s continued the theme of multidisciplinary studies to aid mineral expl oration in sedimentary basins by describing the development of new sta tistical tools for use in conjunction with multivariate analysis, remo te sensing and structural geology. The techniques were tested on the m ineralized regions of Silvermines and Navan in Ireland and the Almaden region of central Spain. The first objective was to develop new softw are for microcomputers to perform interactive statistical analysis of lineament data in a manner suitable for mineral exploration programmes . The first package, ZOOM, has facilities for zoom, pan and overlay, t he display of points and lines and simple transfer to printed document s. The second, SPIDER, allows multiple simultaneous views of data, sta tistical views, dynamic interactive linking and the selection and high lighting of one view while corresponding cases are highlighted in othe r views. The second aim was to develop new statistical methods to anal yse the relationship between mineral deposits and lineaments (shear zo nes). A form of Fourier analysis was used to identify any preferred al ignment of structures in the mineralized areas. The Spanish deposits s howed preferred northeast-southwest alignment, whereas the Irish depos its showed no alignment; in both cases the scenarios are compatible wi th the structural models for the areas. A new statistical technique wa s developed to analyse the relationships between remotely sensed linea ments and the locations of mineral deposits. Again, the relationship b etween the Spanish deposits and lineaments striking at 045-090 was not ed and the Irish deposits showed no such relationship. The function of proximity to lineaments for each deposit was also used to predict the probability of mineralization. Phillips concluded that the new softwa re packages were a valuable aid to mineral exploration. New areas of h igh probability of mineralization were identified in both Ireland and Spain, which, it was suggested, merited further geological evaluation. It was also suggested that the new statistical techniques should be a ccepted with caution.