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.

Primary inclusions are present in apatites from carbonatites and ijolites of the Wasaki, Homa and Tororo complexes of E. Africa. These unique portions of crystallising fluids give valuable information about the nature of carbonatite and ijolite magmas. CO2 - rich, aqueous inclusions, which contain substantial amounts of alkalis, predominate in apatites from these carbonatites. The Na+:K+ weight ratio was found to be in the range 2.4-16.0. Significant amounts of ore metals are also present, as shown by the occurrence of minute, magnetic, crystalline specks within the inclusion fluid. It is concluded that the carbonatitic fluid from which the apatites crystallised, consisted of a highly mobile, CO2 - rich, aqueous saline fluid. Homogenisation temperatures, which represent the minimum formation temperature of the apatites, ranged from about 200°C to 485°C. The mode of homogenisation of one sample, the Uyi carbonatite, indicated that this fluid was supercritical. A higher estimate of the formation temperature (500-590°C) of the apatites from this sample was obtained from the solution temperature of a transient phase (probably Na2CO3) precipitated from the inclusion fluid at high temperatures during heating-runs. Melt inclusions predominate in apatites from the Wasaki ijolites. Carbonate-rich and silicate-rich inclusions are co-genetic in the apatites from some samples. Heating studies have shown that liquid immiscibility between carbonate-rich and silicate melts can occur in ijolitic magmas. Aqueous, CO2-rich, saline fluids may also occur in these magmas. Carbonatitic fluids can be derived from ijolitic magmas. The minimum formation temperature of the Wasaki ijolite apatites was in the range 680°C-950°C. Inclusion studies in apatites from the Homa ijolites showed that the apatites crystallised from a highly saline, aqueous fluid. The minimum formation temperature was in the range 458°C-232°C. Nahcolite (NaHCO3) is described in these aqueous inclusions. This is the first reported occurrence of this mineral in igneous rocks.

A study of fluid inclusions in fluorite from the epigenetic mineralization in lower Carboniferous strata of the Askrigg block in the Northern Pennine Orefield has been made. The purpose of the study was to ascertain the nature, origin and significance of these inclusions and to obtain information concerning the temperature, salinity and chemistry of the environment of crystallization of these ore deposits. The information subsequently obtained oan be used to place constraints on postulated theories of genesis of these deposits. In Chaper 1 a short introduction to the study of fluid inclusions in minerals is given. The suitability for inclusion study of minerals from the Askrigg area is discussed in Chapter 2. A method for the preparation of polished samples is also described together with criteria for the recognition of inclusion types. The importance of the recognition of post-formational changes in inclusions such as leakage and necking-down is also stressed. Chapter 3 contains a detailed geological outline of the ore deposits and a brief review of ideas regarding their genesis. Detailed homogenization studios have been performed on fluorite from numerous localities. The data obtained is then used to determine the minimum temperature of formation of the fluorites. The statistical evaluation of the significance of these results is also described together with details of the positive pressure correction applied to the results. The distribution of temperature in the orefield is described. A detailed account of a freezing stage is presented in Chapter 4. The behaviour of fluid inclusions in fluorite on freezing is outlined together with detailed salinity measurements from various samples. The results obtained are then discussed in the light of other inclusion studies from similar deposits. Chapter 5 contains a detailed appraisal of the analytical methods used to study the chemistry of fluid inclusions. The methods used to analyze leached portions of this inclusion fluid for sodium, potassium, lithium, magnesium, calcium, chloride, and sulphur are described. The chemistry of the ore-forming fluid in the light of these results plus other electronmicroprobe and atomic absorption studies is then discussed. The theories regarding the mode of transport of metals in the inclusion are reviewed in the light of fluid inclusion evidence. The genesis of the ore deposits of the Mississippi Valley type in the light of fluid inclusion studies is discussed in Chapter 6. Comparison is made between the Askrigg and other deposits of similar type and a possible genetic model is postulated for the Askrigg block mineralization.

A study of the British members of the superfamily Beyrichiacea Matthew, 1886 (Ostracoda) has been undertaken. Nearly all of the taxa are Silurian in age; others are, very rarely, found in the Devonian. Wherever possible, extant type material has been located and a primary revision made. Such work has been augmented by studies on new collections, chiefly made from Central England and the Welsh Borderland. The thesis is arranged on a taxonomic basis; the subfamily is taken as the basis for each major section of the work. Other chapters deal with finds of British valves which exhibit intermediary stages in the metamorphosis of the crumina, and with a new beyrichiacean genus which is unique in its apparent lack of dimorphism. One section discusses the faunal distribution of the British Beyrichiacea and compares it with established successions elsewhere. Most of the techniques used, involve standard micropalaeontological practices. Casting methods, and the use of the scanning electron microscope for illustration of the casts, have proved invaluable for working with mould material, and provide an optomistic sign for the future study of ostracode mould faunas. Representatives of the Craspedobolbininae, Amphitoxotidinae, Treposellinae, Beyrichiinae and Kloedeniinae are present. Over 75 named species and some 15 other forms are described; many of the species and genera are new.

Pilot studies on a field area in Sutherland served to establish collective procedures to be used in subsequent work. Detailed sampling of peat was undertaken in the Lake District over an area of copper-lead- zinc mineralisation related to Drygill and Roughtongill mineral lodea Conventional peat augers were found to be unsuitable for the collection of large samples required for research, so a new sampler was designed and constructed which enabled 13cm diameter cores of peat to be readily collected. Experiments were devised to compare the standard techniques used in peat analysis. Results snowed that dry ashing and subsequent acid digestion of the peat ash was the neatest and most efficient total method of analysis, and emphasised the variability in results obtained by different analytical methods. After analysis of the Lake District samples by the total method, the use of partial extractants as reagents for cold extractable analysis V7as investigated. The experiments indicated that molar hydrochloric acid could be used as an extractant in a cold extractable method which was compatible with at niic absorption and colorimetric estimation techniques. A selection of the Lake District samples were then analysed by this method and it was noted that although the new method did not enhance the anomalies indicated by the total methods it still enabled them to be easily identified. Standard cumulative frequency interpretation techniques failed to provide a method for filtering background noise from the data, but this was thought to be due to the type of data, A new method of interpretation involving trend surface and semivariance analysis was highly successful in filtering out the background variation, and also provided data on the strike and length of the mineral veins. Residuals from the trend surface analysis plotted on the sample grid, illustrated the dominant strike of the mineralisation, and semivariance ellipses derived from the variograms described is direction by their long axes.

The data collected in projects of exploration and evaluation of mineral resources is spatially dependent. It is in this context that its analysis should be carried out. The calculation of the Geostatistical semivariance function in as many directions and lags as the data allows permits to identify different degrees of data's internal organization by using iso-semivariance diagrams. Structures within the data are outlined by these diagrams together with their relative position, dimensions and orientations. The technique is arrived at through the development of several computer programs that calculate the semivariance function, transform co-ordinates and produce contourings. Trials on simulated and geochemical exploration data show the close relationship between data's structure and derived functions. The diagrams are also used to assess goodness-of-fit in polynomial data modelling and to develop a computerized procedure for data filtering as predictive models of spatial variability. This procedure consists of the locally fitting of covariance-weighted regression models. Its applicability as a new method of ore reserve estimation is demonstrated with bore hole data from a porphyry copper and a stratabound base metal deposit. Limitations to the technique are imposed by inadequate sampling patterns or impossibility for defining realistic iso-semivariance diagrams. A practical application of alternative conventional Kriging methods in global evaluation of a Bauxite deposit is also presented. From these results, the application of probability analysis in financial appraisal of mining ventures clearly defines the deposit as an important and feasible project.

The reported phenomenon that the F factor was eliminated from the cell under conditions of thymine starvation, was studied because this seemed to be a suitable system to study certain aspects of the control of DNA replication. However, it was found that thymine starvation does not result in the elimination of the F factor from the cell. Thymine starvation of an F prime merozygote stimulates recombination between the episome and the chromosome. Stimulated recombination was studied in a merzygote of constitution lac-z1/F' 1ac-z2. It was found that under conditions of stimulation, the dominant lac+ recombinants and the recessive lac- homogenotic recombinants were produced with different kinetics. This suggests that recombination in an F prime merozygote is most frequently reciprocal. The kinetics of production of the lac+ segregants gave a reasonable fit to a straight line, which suggests that a recombinational event has a single rate-limiting step. An attempt to determine whether newly-formed lac+ recombinants, in the presence of an inducer, synthesised Beta-galactosidase during starvation or after reversal of inhibition, failed because Beta-galactosidase was found to be repressed during thymine starvation. It was thought possible that recombinationless mutants might possess a structural defect in their DNA, which would prevent repair and therefore recombination. To test this hypothesis, the survival after UV irradiation of lambda-bacteriophage grown on mutant and non-mutant hosts, was determined. No differences in survival were detected, and therefore, no evidence was obtained to support the above hypothesis. One of the strains used in this work was found to be sensitive to acridine orange. The genetic basis of this sensitivity was investigated, but this study was not completed.

Subduction-related magmatism and associated mineralization in the north Chilean High Cordillera has been studied within the regional tectonic framework of the Andes between latitudes 28° S and 30°30'S. Geochemical studies focus on the Pre-Andean composite plutonic belt. Rb-Sr geochronology defines a 310-280 Ma plutonic complex and a 240-190 Ma plutonic and volcanic complex. Both have a subduction-related geochemical signature and are characterised by initial Sr ratios of 0.706 to 0.711. Magmagenesis involving contamination by Palaeozoic metasediments of mantle-derived magma is advocated. Individual plutonic units within each complex cannot be related by closed-system fractional crystallization, although this is a viable mechanism with which to model intra-suite evolution. Cenozoic magmatism in the High Cordillera conforms to the progressive eastward migration in the locus of Andean magmatism. Palaeocene plutons to the west of the Pre-Andean belt possess low initial Sr ratios (0.7040) compatible with intrusion through attenuated crust. Intra-basement magmatism of mid-Miocene age possesses higher initial Sr ratios (0.7048 to 0.7063). Although there is a progressive easterly enrichment in Sr ratio with time, there are no systematic trace element variations. It is argued that the Cenozoic magmatism possesses a geochemical signature which is dominated by a mantle component and that the Sr isotopic enrichment reflects a progressive sub-continental mantle enrichment. Epithermal precious-metal deposits that occur in extensive zones of hydrothermal alteration are associated with mid-Miocene magmatic activity. Enrichments in K, Sr, Ba +/- Fe, due to alunite/jarosite +/- barytes +/- celestite precipitation, are intrinsically associated with boiling and vapour separation of upwardly-migrating fluids. Precious-metal mineralization and silica precipitation also occur during this process. A geochemical study of vein material reveals that low-salinity fluids were transporting precious-metals as bisulphide complexes. A model involving the relative abundances of CO2 and H2O, and the initial H2O content, in the primary magma is proposed to explain the styles of mineralization associated with any one magmatic event.

The Llandeilo-Llandovery stratigraphic succession of west Wales comprises fourteen formations and consists of two dominant lithologies, namely sandstone and mudstone, the distribution of which is largely determined by eustatic sea-level changes. The sediments are interpreted as representing distal shelf, sandstone lobes, lobe fringes and slope environments. The turbidite systems developed within the Welsh depositional basin as a Type 1 (unchannelled sandstone lobes) system. The tectonic setting of the basin for the entire period of deposition was that of an active margin. Petrographic and geochemical data, however, indicate a passive margin tectonic setting for the basin. Critical examination of the models suggests that the sedimentary provenance indicators are incorrect and that the signature is a relict one, presumably derived from the Precambrian basement. Laminated hemipelagites are recorded from a number of formations. These formed under anaerobic conditions within the basin. They all contain layered pyrite framboids which are interpreted as having formed diagenetically within the sediment. It is also possible that some of the framboids may have formed syngenetically in the water column. The strata contain a diverse and relatively abundant ichnofaunal assemblage consisting of sixteen ichnogenera: Chondrites, Circulichnis, Cochlichnus, Cosmorhaphe, Desmograpton, Gordia, Helminthoida, Helminthopsi s, Nereites, Neonereites, Palaeophycus, Paleodictyon (Glenodictyon), Paleodictyon (Squamodictyon) , Planolites , Protopaleodictyon and Spirophycus. The ichnogenera are unevenly distributed throughout the succession, the main controlling factors being toponomy, anoxia and a global extinction event.

The Rajmahal basalts of Bihar State, Northeast India, are a suite of Early Cretaceous tholeiites and ferrotholeiites emplaced along the Indian continental margin during the separation of India from Australia-Antarctica. The basalts show a wide range in Pb-Sr-Nd isotopic composition, ranging from ratios typical of Indian Ocean P-type MORB, to those of ancient (>1 b.y. old) continental lithosphere. Relationships between mg#, Rb/Sr, Sm/Nd and eNd suggest that the range in Sr-Nd isotopes is not a mantle source feature, but was produced by interaction between tholeiitic liquids and small-volume partial melts of amphibolite-facies upper crust. However, the range in incompatible trace element concentrations shown by the Rajmahal basalts cannot be explained solely by crustal processes, and must also involve differences in the depth and degree of partial melting. A dynamic melting model is proposed in which polybaric decompression melting of clinopyroxene-garnet lherzolite results in the formation of picritic parent magmas. The generation of picrites requires high asthenospheric potential temperatures (>1400 °C), consistent with melting in close proximity to the axis of a mantle plume. Trace element and isotopic similarities between the Rajmahal basalts and tholeiites from the central and southern Kerguelen Plateau, and palaeomagnetic reconstructions of the eastern Indian Ocean at 118 Ma encourage a link with the Kerguelen plume. Geochemical data from lamproites emplaced shortly before the basalts suggest that the chemical and isotopic composition of the continental mantle beneath eastern India had been extensively modified by heat and material input from the Kerguelen plume. The data imply that the DUPAL isotopic signature of the Indian lithosphere results from 'recent' (~190-140 Ma) metasomatic enrichment of a harzburgitic protolith by asthenospheric small-volume melts. The enrichment event produced a laterally-extensive (>150 km) light REE- and LILE-enriched lithospheric mantle domain, distinct from P-type MORB mantle underlying the Bengal basin.