The re-cycling of sewage sludgeis the most significant entry point for trace metalsin to the agroecosystem. However, the investigation of the transfer and fate of trace metals in soil-plant-arthropod systems in an agricultural context has received little attention, despite the potential threat that secondary toxicity to predatory arthropodsposes to the biological control of crop pests.In this study, an agricultural soil was amended with sewage sludgeat rates up to an equivalent of 100 t (dry solids) ha-1.The subsequenttransfer of Zn and Cd through an ecologically relevant soil-crop-aphid-arthropod predator systemwasinvestigatedin a series of pot trials. Results show that Zn was transferred to a greater extent than Cd between all components of the system, except between the roots and shoots. Cadmium was only biomagnified in roots and was biominimised in shoots, aphids and ladybirds. Zinc was biomagnified in roots, shoots, andaphids compared to the soil, but concentrationsin ladybirds were similar to those in the aphids they consumed.Differences between winter and spring wheat were found to have a larger influence on the transfer of Cd and Zn in the systemthan differences between winter wheat and spring barley. It was also shown that the rose grain aphid (Metopolophium dirhodum) accumulateshigher concentrationsof Cd than the grain aphid (Sitobion avenae).Whilst concentrationsof Zn did not differ between the two species of aphid, concentrations in M. dirhodum appearedto be more closely regulated than in S.avenae. Consumptionof S.avenaeby the fourth instar larvae of the seven-spottedladybird (Coccinella septempunctata)did not result in significant differences between treatmentsin newly emergedadults.This was partly the result of the sequestrationof the two metalsin the pupal exuviae. This mechanism had a greater effect on the Cd concentrations in newly emerged adult ladybirds than on Zn concentrations.In a further experiment,there appeared to be no pathway for the transfer of Cd from aphids to adult ladybirds, but a pathway was indicatedfor Zn. The implications of the results are discussed in relation to the agroecosystem andthe wider environment.

An Analytical Study of Earth and Lime Based Building Materials in the Blumenau Region, Southern Brazil. In the last fifteen years, there has been a growing state and national interest in the preservation of historic rural settlements of the nineteenth and twenty centuries in southern Brazil. This interest has generated a need to develop appropriate conservation methods which will safeguard the integrity and technology of vernacular buildings in Brazil. This study focuses on the Blumenau region, an area in the state of Santa Catarina which was settled by German and Italian immigrants in the late 19th century. As was typical in such settlements, the immigrants brought with them European methods of construction which were then adapted to the local environment and available local materials. Though somewhat deteriorated, Blumenau still retains a large number of vernacular building types and good documentary sources of information. Thus, it provided an ideal context in which to develop a methodological approach to the study and conservation of regional building materials in Santa Catarina. Twenty domestic buildings dating from approximately 1870 to 1930 and representing the four principal types of construction in the area were chosen for the pilot project. In addition to thorough historical and archival research on the architecture and technology of the region, the study includes an in-depth scientific analysis of earth and lime- based buildings materials utilised in the rural settlement. The analytical results are interpreted in light of the historical research and recommendations are made regarding appropriate conservation and repair techniques. The study concludes with general recommendations for improved conservation practice in the region including issues of material production, training, and management. The work includes an extensive bibliography relating to the characterisation and conservation of earth and lime- based building materials. Full details of analytical techniques utilised are given in the appendix.

District-scale zoning of ore deposits and structural-tectonic setting of Bau was investigated. Regional tectonic studies, structural analysis, and field mapping complemented by aeromagnetic interpretation were integrated to a structural model of Bau. Ores were studied with optical and electron microscopy, followed by major and trace element, fluid inclusion, and lead and sulfur isotope analyses. In the Late Triassic, Bau was in an island arc - back-arc basin environment Following Early Jurassic deformation and uplift, an active margin developed. Subduction of the West Pacific oceanic plate under the NW Kalimantan block began. Erosion of the Triassic Serian Volcanics produced extensive turbidite flows of the Pedawan Formation since the Latest Jurassic. Coeval development of rudist patch reefs on an unstable shelf edge of the overriding plate lasted until Cenomanian. Accretion of the turbidites ended in the Latest Cretaceous. Early Tertiary molasse deposition ended with a Mid-Eocene event. A 200-km-Iong, crustal-scale complex fault system involving dextral strike-slip and wrench faulting, termed the Bau Trend, developed during Mid-Miocene post-subduction regional extension. The principal mineralization event at Bau took place at 12-10 m.a., when I-type, calc-alkaline, reduced granodiorites intruded along the Bau Trend and its intersection with seven parallel, ENE fracture zones, providing channel ways to distribute hydrothermal fluids laterally away from the Bau Trend. Deformation preceding mineralization produced high structural permeability of the host rocks. Central Bau is underlain by an ENE trending, 5x12 km broad plutonic body at depth, inferred from aeromagnetic data. Bau displays district-scale zoning, from proximal porphyry-copper and skarn deposits, via intennediate Cordilleran-Vein base metal mineralization, sediment-hosted precious metal deposits, to distal disseminated Au-As and Ba-Hg-TI deposits. The deposits are hosted in, from proximal to distal, porphyritic granodiorites, limestones, and turbiditic shales. Gradual changes in geochemical, mineralogical, and isotopic compositions across the district indicate consanguinity between them. Epithermal gold mineralization at Bau is most similar to disseminated, sediment-hosted gold deposits of Nevada, except for higher grades, visible occurrence of gold, both base and precious metal signatures, purely structural controls, less radiogenic lead, and magmatic sulfur isotope signatures.

The Toarcian, Early Jurassic, Oceanic Anoxic Event (T-OAE: ~183 Ma) was characterized by globally synchronous deposition of sediments rich in organic carbon (black shales), and is associated with an abrupt negative carbon isotope excursion, disrupting a positive carbon-isotope excursion during the tenuicostatum–serpentinum ammonite Zone boundary. The T-OAE has been extensively studied in northern and southern Europe, but evidence from the southern hemisphere is limited. New geochemical data from the tenuicostatum–hoelderi (~serpentinum) Andean ammonite Zone, from the Neuquén Basin, Argentina provides evidence for the global imprint of the event. The event is recorded in bulk-sediment from Arroyo Lapa (North and South) and Arroyo Serrucho with δ¹³C_org values of -30‰ – -32.5‰ and δ¹³C values from fossil wood fall to -30.7 ‰, isotopic ratios that are comparable to those identified in Europe for the T-OAE. Hydrogen Index (HI) data for the T-OAE in Argentina give values ranging from 12 to 425 mg HC/ g TOC, indicating a mixture of terrestrial and marine organic components. Pristane/Phytane ratios and pyrite framboid distribution data indicative of anoxic conditions occur at some levels, and new δ^98/95Mo data, with values ranging from ~ -0.2 to 0.78 ‰, which contrast with previously published molybdenum-isotope values from T-OAE black shales of northern Europe. Sedimentological data also reveals a marine transgression during the tenuicostatum–hoelderi Andean ammonite zone.

The 'RMnO3': R = La, Nd, Pr, phases have been synthesised and characterised by a combination of electron probe microanalysis (EPMA), H2-reduction thermogravimetry (TG), x-ray (XRD) and neutron diffraction (ND). RMnO3 forms, at" 1400C, over the ranges: NdMn0, 95Oz to Nd0 88MnOz PrMn0.97O2 to Pr0 88MnOz LaMno 0.90Oz to La0.97MnOz Oxygen contents vary in air over the range 700 to 1400 C and can be varied further, either by high pressure Oz treatment or by reduction in H2. The structure of 'RMnO3' R = Nd, Pr is based on the GdFe03 structure with a Jahn-Teller distortion associated with the high proportion of Mn3+ ions present. The oxygen deficient 'LaMnOz' compositions also exhibit this structure consistent with earlier reports. By combining EPMA, TG, XRD and ND results various defect models describing the stoichiometry and structure of Mn-rich and R-rich, R = Nd, Pr compositions have been summarised. Both R = Nd and Pr systems exhibit very varied defect structures; depending on composition and heat treatment, vacancies can form on any one or any two of the three sublattices, R, Mn and O and the overall Mn oxidation state can include 2+, 3+ and 4+ contributions. For 'RMn03': R = La, Nd, Pr, data on their compositional ranges and defect crystal structures are presented in the form of novel phase diagram-defect structure maps from which the principal defect structure for a given stoichiometry can be easily obtained. The majority of the Pr-Sr-Mn-O pseudotemary phase diagram has been determined. EPMA was used to follow the progress of reaction and the conditions to achieve complete reaction established. Several solid solutions were evidenced, some previously unreported (3 - 6): 1) Pr1.xSrxMnO3 0[Special character omitted]x[Special character omitted]1.0 2) Pr1+xSr2.xMn2O7 0 [Special character omitted]x [Special character omitted] 0.4 3) SrxPr1-xO2 0[Special character omitted]x[Special character omitted]0.16 4) Sr1-xPrO3 0[Special character omitted]x[Special character omitted]0.15 5) Sr2.xMnxO4 6) Sr2.xPrxMnO4 The perovskite-like Pr1-xSrxMnO3 solid solution extends from PrMnOz to SrMnOz. The unit cell symmetry changes from orthorhombic to rhombohedral to tetragonal to cubic and finally to hexagonal as the Sr content increases. The limits of the Ruddlesden Popper (RP) n=2 Pr1+xSr2_xMn2O7 solid solution were determined: 0 [Special character omitted] x [Special character omitted] 0.4 and a tetragonal unit cell observed consistent with the literature. Synthesis of the RP compositions by solid state methods requires long heating times (up to 36 days) to produce homogeneous samples; qualitative EPMA of younger samples indicated an inhomogeneous distribution of Pr and Sr. Contrary to EPMA results, XRD of younger samples indicated that complete reaction had occurred and single phase compositions produced. It is suggested that the SrxPr1-.xO2 solid solution extends over the range 0 [Special character omitted] x [Special character omitted] 0.16 where similarly to the polymorphism of praseodymium oxides, compositions 0.03 [Special character omitted] x [Special character omitted]0.16 exhibit the cubic fluorite-type structure of Pr6O11 and x [Special character omitted] 0.03 is a mixture of cubic SrxPr1-xO2 and hexagonal SrxPr2.xO3. Perovskite-like SrPrO3 exhibits variable cation ratios; the Pr-rich boundary is Sr0.85PrOz. The lower Sr-rich boundary is yet to be identified. Similarly to 'RMnO3': R = La, Nd, Pr, the oxygen content of 'SrPrOz' is expected to vary. Therefore, various possible defect structures describing vacancies on the three sublattices, Sr, Pr and O could exist and charge compensation would be an interesting example of ionic and electronic mechanisms where Pr adopts the +4 and +3 oxidation states. Four layer hexagonal SrMnO3 exhibits variable Sr:Mn ratios but the solid solution limits are not yet known. The unreported Sr2-xPrxMnO4 solid solution has been observed but the solid solution limits are not yet known. The K2NiF4-type structure of Sr2Mn04 is retained at x = 0.75 and is expected to contain Mn3+ as Mn4+ is reduced to compensate Sr24 substitution by Pr3+.

Earth has been used as a reliable building material for many thousands of years. Recently there has been a world wide renaissance in the use of earth as a building material due to its architectural versatility and environmental sustainability. However, in the United Kingdom it is regarded by the majority of building professionals as either obsolete or a novel historical material. The utilisation of earth as a modern building material and the repair of historic earth building structures is retarded by the uncertainty of the knowledge of the properties of the material. This thesis considers earth building materials as composite materials containing a cohesive, low compression modulus binder fraction, a high compression modulus aggregate fraction, and a fibre fraction. The compression properties of a building material without fibre content (cob matrix material) are described in terms of the interaction between the binder and aggregate fractions, and moisture and the binder fraction. The effect of the moisture content of the material upon the compression failure mechanisms is described. Values of compression modulus predicted by a rule of mixtures equation are compared to experimental results for this material. The following mechanisms are proposed to account for the apparent discrepancy between the predicted and experimental results: • the effect of pore size distribution and the proportions of binder and aggregate fractions upon strain magnification within the material • the effect of an efficiency factor, primarily dependent upon the proportion of binder and aggregate fractions, which determines the degree to which the potential modulus of the material is realised. Time Domain Reflectometry is employed for repeated, real time, non-destructive measurement of the moisture content of an external cob wall. The results of these measurements are analysed and discussed. This thesis proposes that consideration of cob as a composite material has developed a paradigm which will enhance the level of understanding of all earth building materials, enabling the manipulation and accurate prediction of their structural properties. This will be an important contribution to the realisation of the significant sustainable qualities of earth building materials by the current construction industry. -

Detailed mapping of the rocks to the north and south of Plymouth reveals a sedimentary sequence deformed by a series of folds and thrusts. Two structural zones exist each with a different style of deformation. In the Lower to Upper Devonian rocks of the southern zone, slip vectors, vergence and facing of D 1 folds indicate that the transport direction is to the north west. The northern zone, comprising Upper Devonian and lower Carboniferous strata, extends into central Devon and east Cornw~ll and the geometry and facing of the early folds in these rocks indicate a transport direction to the south or south east. Dl folds generally verge north but are downward facing towards the south. The two structural zones confront each other at an E-W trending line which passes through Cargreen to the north of Plymouth. The confrontation is interpreted as a northerly dipping backthrust produced by underthrusting of the Carboniferous foreland basin flysch deposits which become inverted and backthrust towards the south. The above sequence of events is dependent on a thin-skinned tectonic model and can be incorporated into the well established Early Carboniferous plate tectonic setting. Parameters indicating strike slip movement can also be incorporated within the envisaged thrust regime. These are thought to have been generated by differential movement related to the shape of the Variscan Front. The oblique trend of the Variscan Front to the regional transport direction observed in Southern Ireland, Wales and England, where it trends WNWESE, is thought to be a function of lateral buttressing against the Irish and LondonlBrabant Massifs during NW transport of thrust sheets. Re-mapping in the Plymouth area has also led to modifications of the Devonian stratigraphy and sedimentology of the Lower Devonian. The previously named Dartmouth Beds/Slates have been re-named the Dartmouth Group and comprise the Renney Rocks, Wembury, Yealm and Warren Formations. The latter pass upwards, by interdigitation, into the Meadfoot Group which in turn consists of the Bovisand and Staddon Grit Formations. Overlying the Meadfoot Group is the Plymouth Group which is divided into the Jennycliff Slate Formation, Plymouth Limestone Formation, Compton Slate Formation and the Saltram Slate Formation. The division of the previously named Plympton Formation into the two latter formations has allowed more control on structural mapping in the area north of Plymouth. The recognition of repeated stratigraphy and its further subdivision indicates that, due to thrusting, the sequences are much thinner than previously thought. The sedimentological character of the Dartmouth Group implies deposition in an alluvial setting and sub-environments include channels, sheetflow, overbank flow and lake deposition. Debris flows indicate that the area was periodically unstable. It is envisaged that deposition took place on a wet alluvial plain with rare drying out. The deposits probably represent a distal setting to the more proximal Old Red Sandstone alluvial deposits of South Wales. Higher up the sequence the Meadfoot Group records a major marine transgression across the area (Bovisand Formation) with a minor regressive pulse represented by the Staddon Grit Formation. The boundary conditions of these two formations has been examined and the sedimentology of this part of the sequence indicates the presence of a series of offshore bar forms. They are thought to represent mouth bar sequences related to the overlying deltaic sequence of the Staddon Grit Formation. Analysis of the onshore New Red Sandstone indicates the presence of a topographic high in the Start area. This local palaeogeographic detail can be related to the regional offshore Permian Basin form.

The “deltaic” geomorphology in the Eberswalde Crater is often considered a “smoking gun” for the warm-and-wet ancient climate of Mars. The Crater displays sedimentary features, which many argue, can only be found in a river-delta system (Bhattacharya et al., 2005). However, with the advent of high-resolution images, the Eberswalde Crater delta’s geomorphology has been revealed to be more complicated than could be seen previously. These high-resolution data suggest that the development of the Eberswalde delta is likely more episodic (Schieber 2007). While better resolution data has placed doubt on the wet Mars hypothesis at the Eberswalde Crater, the opposite is true of the Gale Crater. Recent images acquired by the Mars Curiosity Rover have revolutionized the hypotheses explaining the formation of Mount Sharp in the Gale Crater. The new prevailing hypothesis is that Mount Sharp was formed by a series of crater lakes (NASA, 2014). This study provides evidence supporting the crater lake hypothesis, using bedding architecture diagrams, facies diagrams, lithologic logs, paleocurrent map and rose diagram, and minimum water depth estimations of the exposed sedimentary layers. Reconstructing a detailed depositional history of the Gale Crater Lake provides a window into a more ancient Mars where life could have evolved in a wet habitable climate that is absent today.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1987. / Vita. / Bibliography: leaves 131-133. / by Yung-An Lee. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmosphere and Planetary Sciences, 1987. / Bibliography: v. 2, leaves 260-271. / by Alan Edward Leinbach. / M.S.