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presented. Several new proposals are made for the measurement and classification of fossil footprints. Field studies by the author have revealed many new vertebrate footprint discoveries in the British Triassic, including one at Hilbre, Wirral which is one of the most complete footprint assemblages found in recent years. Field case studies are presented for three localities: The Bendricks in S, Wales, Hilbre Island, Wirral, and Hollington, Staffordshire. New discoveries at Hollington confirm that the site has a typical Mid Triassic assemblage of footprints of medium-sized archosaurs (Chirotherium sp.) and small diapsids (Rhynchosauroides sp.). The Hollington footprint assemblage is comparable to better-known assemblages from Storeton and Runcorn in Cheshire dated as Lower Anisian. The sedimentary nature and organisation of the lithofacies suggests a fluvial environment which was initially of low sinuosity but became more sinuous later. A major review of the ichnofamily Chirotheriidae in the British Triassic shows that there are at least three valid ichnospecies of Chirotherium, one of Synaptichnium, and one of Isochirotherium. The presence of a fourth related ichnogenus. Brachychirotherium. is unclear and cannot yet be confirmed in Britain. A comparison of the lithostratigraphy of footprint localities shows that Chirotherium. Synaptichnium and Isochirotherium can only be confirmed in British Middle Triassic rocks of Lower - Middle Anisian age. These results are almost certainly not a true reflection of the stratigraphic distribution of these ichnogenera, but probably highlight the facies dependant nature of footprint preservation. Probable Chirotheriidae footprint forms occur throughout the British Triassic in rocks of Lower Scythian to possibly Upper Norian age. Unfortunately, the quality of Lower and Upper Triassic specimens obtained to date is relatively poor; hence identification of these footprints to ichnogenus level is difficult. A taxonomic review of the morpho-family Rhynchosauriidae in the British Triassic was undertaken. There is evidence to suggest that the "Rhynchosaurus" footprints found by Ward at Grinshill, Shropshire, in 1838, which later gave rise to the establishment of the ichnogenus Rhynchosauroides. should be reassigned to the ichnogenus Rotodactylus Peabody 1948. This study confirms the occurence of Rotodactyl us in the British Triassic. Twenty British Triassic footprint forms that have been previously, or are presently, assigned to the ichnogenus Rhynchosauroides, together with five other related forms have been restudied. Two are considered to be Rotodactylus sp.; one is reassigned to the chirotheroid ichnogenus Synaptichnium sp.; five are considered poorly preserved examples of either Rotodactylus or Rhynchosauroides and have been reassigned to ichnogenus indet; one is considered to be an inorganic sedimentary structure and is referred to ichnotaxa indet; and only six are considered to be forms of Rhynchosauroides. Rhynchosauroides is recorded and confirmed from at least twelve British localities, and Rotodactylus from seven.The lithostratigraphic range of Rotodactylus is ?Middle Scythian - Middle Anisian, Lower - Middle Triassic. The lithostratigraphic range of Rhynchosauroides is ?Middle Scythian -Upper Carnian (possibly Norian), Lower - Upper Triassic. The oldest skeletons of dinosaurs date from the Late Triassic (Carnian) but supposed dinosaur footprints have been reported from Early and Mid Triassic ;rocks dated up to 20 Myr: ~earlier. A restudy of several.museum specimens was undertaken; supposed Lower Triassic dinosaur footprints from Britain are reinterpreted as ripple marks, mud rip-up clasts, and possible limulid prints. The Middle Triassic material is reinterpreted as partial specimens of Chirotherium , presumably produced by rauisuchians and one indeterminate specimen, possibly also of chirotheroid affininites. The oldest dinosaur footprints from Britain come from the marginal Triassic (Non an, Upper Triassic) in South Wales. Elsewhere 10 the world, the oldest dinosaur footprints appear to be Carnian corresponding in age to the oldest skeletal remains

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From Introduction: With the rapidly growing knowledge on trace elements and their influence on plant nutrition the need for accurate and rapid methods for their determination arose. The essential plant nutrients are usually divided into two groups. The major or macronutrient elements, necessary in comparatively large amounts, and the trace or micro-nutrient elements. In the case of plants, the first group includes Sulphur, Phosphorus, Potassium, Magnesium, Calcium and Nitrogen. The essential trace elements are Iron, manganese, Boron, Copper, Zinc, Molybdenum and Chlorine. Cobalt is essential for animal nutrition as a constituent of Vitamin B₁₂, but its essentiality for plants has not yet been proved. The latter group consists of metals which are catalysts in enzyme reactions and whose presence in the plant in minute amount determines whether the plant will be able to complete the vegetative or reproductive stage of its life cycle. Molybdenum may be quoted as an example of an essential trace element. It is generally recognised to be the catalyst responsible for the fixation of Nitrogen.

The instrumentation and methodology for real-time computer controlled scanning potential coulometry for multi-component trace analysis is described. The sensitivity limit was determined to be 10^-8 F for electrochemically reversible constituents. The sensitivity limit could be extended if measures were taken to compensate for the periodic signal found on the electrolysis current. Non-linear least squares curve fitting methods accurately resolved iron-platinum and silver-iron interferences to give accurate determinations for iron and silver. The resolving capability of this method was tested using theoretically generated scanning potential coulograms. The computer resolved sample constituents with a 1 to 100 concentration ratio and a formal potential separation of 10 millovolts. It also accurately resolved sample constituents with a 1 to 1000 concentration ratio, one with 1 equivalent per and the other with 2 equivalents per mole, but with no formal potential separation.

Bibliography: pages 94-99. / This thesis describes work performed to establish and demonstrate a quantitative trace element microanalysis technique for geological material using protons accelerated by the Van de Graaff Accelerator at the National Accelerator Centre (NAC) in Faure near Cape Town. The method relies on the analysis of Proton Induced X-ray Emission (PIXE) spectra, interpreted with the help of the GeoPIXE software package. The use of the Si(Li) energy dispersive detector provides simultaneous multi-element detection at the parts-per-million (ppm) level, and a scanning beam facility permits trace element distributions to be studied at these levels. The calibration of the detector efficiency and the thicknesses of selectable X-ray attenuating filters was performed using pure elemental samples. This involved the accurate determination of the target to detector distance, the thickness of the active volume of the Si(Li) detector crystal, the thicknesses of all the absorbing layers between the sample and the detector crystal, and the assessment of the effects of incomplete charge collection in the detector.

The distribution and speciation of trace metals in natural waters is only slightly, at best, understood. Interactions with organic substances can effectively distribute the metals throughout many ill-defined physical and chemical. To better comprehend the complexity of metal-organic interactions this work focused on the delineation of trace iron species present in a natural system. The separation of Fe(II) and Fe(III) was successfully accomplished using a variation of an ion exchange method involving resin-loaded filter paper. The quantitation of the various iron species was determined using linear scan voltammetry and atomic absorption. The total iron concentration, determined as the sum of the various separate species, compares favorably with the total iron concentration as determined directly using atomic absorption methods.

The 1990 Clean Air Act Amendment (CAAA) contains provisions that will establish new emission standards for 190 potentially hazardous air pollutant precursors (HAPPs). Studies have suggested that many of these HAPPs have the potential to be removed prior to combustion. This thesis details the findings of a bench-scale test program that was implemented to evaluate the capabilities of physical coal cleaning technologies on the removal of trace elements from coal. Test work was completed on Pittsburgh No. 8 seam coal that was processed using physical cleaning techniques (i.e., crushing, dense media separation, froth flotation, and enhanced gravity separation). The bench-scale test circuit incorporated crushing and rewashing a coarse, mid-density product with hopes that trace element rejections would improve due to greater liberation of HAPPs. The results of this investigation showed that trace elements were predominately rejected in the coarse coal portions of the processing circuit (i.e., dense media separation), and only slight improvements in rejections could be realized from crushing any portion of the coal. It was also shown that trace element rejection could be incrementally increased with minimal loss of total yield or combustible recovery when froth flotation is put in series with enhanced gravity separation. The results of the bench-scale test work, along with trace element float-sink and release analysis data, were used to develop a simulator that can predict trace element rejections from any coal processing circuit. This was achieved by applying general partition functions to trace element washability and bench-scale processing data. Simulation studies included comparing three physical coal cleaning techniques. The results of these analyses showed that although no net improvement in trace element rejection can be gained through crushing the circuit feed, there is a slight increase in product yield. Crushing a mid-density coarse coal product also showed little or no improvement in trace element rejection. / Master of Science

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