This investigation focuses on two well-preserved impact structures developed in sedimentary target rocks: the ~23.5 Ma old Haughton structure, Canada, and the ~14.5 Ma old Ries structure, Germany. The aim of this study was to investigate the effects of hypervelocity impact into sedimentary targets. The study reveals that a series of different impactites are present at Haughton, the bulk of which comprise a groundmass of impact-generated melts (calcite + silicate glass ± anhydrite). Thus, carbonates, evaporites, sandstones, and shales underwent shock melting during the Haughton impact event. The shock melting of impure carbonates resulted in the generation of Mg–Ca–Si-rich melts that crystallized calcite during rapid cooling. The residual melt quenched to Mg–Si-rich glass. These impactites should, therefore, be classified as clast-rich impact melt rocks or impact melt breccias, and not clastic matrix breccias as previously held. Ries surficial suevites are reinterpreted as clast-rich impact melt rocks or impact melt breccias. Four main types of impact melt glass are present, in contrast to previous studies that recognized only one type. These results are at odds with the current, generally accepted, definition of suevite. Given that the Ries is the original type occurrence of ‘suevite’, some redefinition of the term suevite may be in order. Furthermore, it is clear that sedimentary rocks, as well as crystalline rocks, were shock melted during the Ries impact event. The results of this study are, therefore, incompatible with previous models in which the zone of melting is restricted to the crystalline basement. It is apparent that impact melting in sedimentary targets is much more common than previously thought. Furthermore, there is no unequivocal evidence for the decomposition of carbonates or evaporites at any terrestrial impact site. Many previous assumptions about the response of sedimentary rocks during hypervelocity impact events are, therefore, incorrect. The products of impact into sedimentary targets may appear very different from those developed in crystalline targets. However, microscopic imaging and analysis suggests that these seemingly different lithologies may be genetically equivalent. Thus, the apparent ‘anomaly’ between the amount of impact melt rocks formed in sedimentary and crystalline targets may be due to a misinterpretation of the rock record.

Techn. Hochsch., Diss., 2004--Aachen.

No description available.

Placoderms are restricted to the Devonian in the Prague Basin, occuring on localities dated from the Lochkovian to the Givetian. Černá rokle near Kosoř with the Radotin Limestone is the richest placoderm bearing locality. A revision of specimens from collections of the National Museum in Pra- gue confirms occurences of three species of two genera belonging to the pla- coderm order Acanthothoraci: Radotina kosorensis Gross, 1950; Radotina tesselata Gross, 1958 and Kosoraspis peckai Gross, 1959. Genus Holopeta- lichthys was accepted as valid and a diagnosis of H. primus (Barrande, 1872) was amended. Its assignment to higher taxonomic units remains uncertain. Four morphological types of undeterminable specimens classified in the order Arthrodira are defined. Some previously unpublished morphological structures are figured and described: the median dorsal plate of the thoracic armour of R. kosorensis and its relation to the head shield, the cranial cavities and trunk shield plates of R. tesselata, a well preserved neurocranium and scales of K. peckai, the trunk shield and vertebral column of H. primus and large dermal plates of each Arthrodiran morphotype. The placoderm diversity in the Prague Basin was lower compared to ne- ighbouring areas at the beginning of the Devonian (Lochkovian and Pra- gian). Only...

This thesis deals with early vertebrate fossil remains from the Lower Palaeozoic strata of the Barrandian area (Bohemian Massif). It is presented as a compilation of four papers that were published or submitted in scientific peer-reviewed journals with impact factor. All included papers are focused on the most abundant and diverse vertebrate fauna from the Barrandian area - the placoderms. Placodermi are early vertebrates characterized by articulated head and trunk shields composed of dermal bony plates. In the Barrandian area, they occur exclusively in the Devonian of the Prague Basin. The main objectives of the thesis are modern taxonomic revisions of the placoderm taxa from the Prague Basin as well as discussions about trends in their abundance, diversity, and distribution in space and time, taphonomy, and the evolutionary and phylogenetic implications of their morphology. Two characteristic placoderm associations were distinguished. In the Lochkovian and Pragian, members of the group Acanthothoraci dominate the placoderm record. Acanthothoracid placoderms are among the most basal jawed vertebrates and thus a detailed study of their morphology has a great potential to illuminate the relationships and evolutionary patterns among the stem jawed vertebrates. They are most abundant in the...

<p>This investigation contributes to the existing scholarship on Britain and the First World War by examining the war's impact on the county of Devon in southwest England. More specifically, this study pays particular attention to how communities, families, and individuals responded to the pressures of war and to what extent social unity was achieved at the county level. By exploring the relationship between the state and its citizens, this dissertation questions the extent to which Devonians were passive and accepting of the sacrifices and hardships that the government required from them, how their experiences were informed, and to what extent class, gender, and religious differences limited public support for the war? While this dissertation argues that Devonians were generally supportive of British participation in the war, that support was provisional and based on the perception of 'equality of sacrifice' - the expectation that the burdens of war would be shared equally throughout the county and across all segments of society. This study reveals that the inequalities of sacrifice and inconsistencies of government policies burdened some groups more than others and led to social disaffection. Rather than promoting solidarity, the war often exacerbated rural/urban tensions, highlighted the social and economic divisions that characterized relations between the communities of northern and southern Devon, and led to frequent and public criticisms of the government's management of the war.</p> / Thesis / Doctor of Philosophy (PhD)

In dieser Arbeit werden Berechnungen zur klimatischen Sensitivität der Eiskappe von Devon Island (Nunavut, Kanada) durchgeführt, die auf einem mit Wärmesummen arbeitenden Massenbilanzmodell basieren. Wichtigste Datenbasis für die Modellrechnungen sind dabei höhenabhängige Massenbilanzreihen der Devon-Eiskappe sowie tägliche Klimadaten der WMO-Station Resolute Bay. Durch die Bestimmung geeigneter Modellparameter (Temperaturgradienten, Wärmesummenkoeffizienten) ist es möglich, das mittlere Massenbilanzprofil gut zu simulieren. Das auf diese Weise kalibrierte Modell kann dann – als einfache Alternative zu Energiebilanzmodellen – zur Berechnung der Sensitivität der Massenbilanz auf Veränderungen von Temperatur und Niederschlag genutzt werden. Anwendungen des Modells verdeutlichen, dass die Massenbilanz der Devon-Eiskappe stark abhängig von der Entwicklung der Sommertemperaturen und die klimatische Sensitivität im Vergleich mit anderen Eismassen aus feuchteren Klimaten sehr klein ist. Die Einbeziehung der saisonalen Abhängigkeit der Massenbilanz kann schließlich helfen, eine mit Schwierigkeiten verbundene Rekonstruktion der jährlichen Massenbilanz zu verbessern. / In this study, a degree-day approach is used to carry out model simulations to determine the climatic sensitivity of the mass balance of the Devon Island ice cap (Nunavut, Canada). The most important data the model is fed by are a 38 yr long series of specific mass balance data and daily air temperature data from the WMO station Resolute Bay. By determining suitable model parameters (temperature lapse rates, degree-day coefficients) it is possible to simulate the mean mass balance profile convincingly. As a simple alternative to energy balance models, the calibrated degree-day model can then be used to determine the sensitivity of the mass balance to changes in temperature and precipitation. Results show that the mass balance of the Devon Ice Cap is strongly dependent on the summer temperatures and that the overall climatic sensitivity is small compared to those of other ice masses in more humid regions. The reconstruction of the mass balance series is attended with difficulties, but can be improved by including the mass balance''s seasonal sensitivity.

This thesis examines the experiences and impact of wartime mobilization in the county of Devon. It argues that a crucial role was played by the county’s elites who became the self-appointed intermediaries of the war experience on a local level and who took an explicitly exhortative role, attempting to educate Devonians in the codes of ideal conduct in wartime. These armchair patriots, defined by the local commentator Stephen Reynolds as ‘provincial patriots’, superintended the patriotism of Devon’s population, evaluating that patriotism against the strength of their own. Through a critical exploration of Reynolds’ definition of Devon’s elite as the police-men and women of patriotism, this thesis reveals the ambiguities, constraints and complexities surrounding mobilization and remobilization in Devon. The evidence from Devon reveals the autonomy of Devon’s citizens as they attempted to navigate the different challenges of the war while they weighed-up individual and local interests against the competing requests that the ‘provincial patriots’ prescribed for them. In many cases, their responses to the appeals and prescriptions from Devon’s elite were informed by what they considered to be an appropriate contribution to the war effort. Therefore, the choice to participate in the measures introduced in the name of war effort in Devon was not a binary one. A tension between individual survival and national survival in the county was apparent in the encounters between Devon’s elite as agents of mobilization and the county’s populace during the war. Through various campaigns of superintendence in order to police the patriotism of Devon’s people, the ‘provincial patriots’ attempted to navigate through the terrain of these competing priorities and resolve this tension. In their endeavours to mobilize Devon’s populace, the authority of Devon’s elite was criticised and they faced constant negotiation between individual priorities and those of the nation. This analysis of the complexity of the Devonian experience of the First World War is sceptical about the ‘total’ nature of the First World War because the war to some Devonians was not the pre-eminent issue and did not absorb all of the county’s efforts. Rather, a significant part of Devon’s population was primarily concerned with individual priorities and that of the county throughout the war years.

Recent work has sought to explain the striking variations in municipal hospital provision in the 1930s by quantitative analysis. Such work has not so far provided a hypothesis which satisfactorily explains the range of variations found. This study, grounded in an analysis based on the Advocacy Coalition Framework and the results of three case studies of events in the county boroughs of Plymouth and Exeter and in Devon County Council, uses a qualitative methodology developed by iteration between a deductive approach drawing on recent work and an inductive approach using a computer-assisted analysis of primary source material and proposes a new hypothesis. The hypothesis developed is that where a local authority inherited a Poor Law workhouse as a result of the Local Government Act (1929) development would be more likely to occur in places where councillors exhibited strong progressive beliefs in accountability to the wider community and in their social responsibility towards that community; where they had successful experience of direct hospital provision in other fields; and when they had available a committed entrepreneur able to marshal support for change within the council. In addition to its empirical findings the study contributes to the development of public policy theory by suggesting improvements to the Advocacy Coalition Framework. Such improvements comprise recognition of the importance of ‘deep core’ as well as ‘policy core’ beliefs to policy change, consideration of path dependency as a significant method of policy learning, and of the roles of entrepreneurs and policy brokers. Finally the study draws attention to the relevance of the study to current practice in the implementation of public policy and proposes specifically that local NHS agencies should give greater prominence to identifying and supporting individuals with the skills of policy entrepreneurs.

Lower Devonian foraminifera are known from only a few localities globally and thus are not much investigated. The taxonomy, as well as further use of this group is insufficiently known. One of the main areas of research of foraminifera is the Barrandian area in the Czech Republic. This thesis follows previous studies of this territory but focuses particulary on the Prag formation, which has proven to be rich in foraminifera communities. Taxonomic studies were conducted at two Lower Devonian sites, namely the Na Stydlých vodách quarry and the Požáry quarry. The study showed that foraminifera communities described from the Na Stydlých vodách quarry were dominated by the following genera: Hyperammina, Colonammina and Tolypammina. The highest abundance was recorded at the transition of dvorecko-prokopské limestones and řeporyje limestones and in dvorecko-prokopské limestones. At the Požáry quarry, the communities were dominated by tubular genera of Tolypammina, Hyperammina and Bathysiphon and spherical genera of Lagenammina and Colonammina. The abbundance of Colonammina is unusually high, the genus has been described rarely from other parts of the world so far.