Non-axial planar cleavage and Caledonian sinistral transpression in eastern Ireland

Transected F₁ fold structures in eastern Ireland are associated with subhorizontal stretching in the S₁, cleavage whereas axial planar cleavage contains a vertical elongation direction. This suggests that the non-axial planar cleavage was influenced by a distributed strike-slip ductile shear. A major NE-SW trending F₁ syncline is described in which the minor F₁ folds show systematic variations in cleavage transection parameters. On the steep limb of the major syncline the cleavage transects the minor F₁ folds in a consistently clockwise sense, whereas on the normal limb anticlockwise transected folds are seen. Axial planar cleavage occurs at the core of the major syncline. Fold profile analysis indicates that the buckling of the layers began before the initiation of the cleavage. Open, parallel folds at the major synclinal hinge zone are progressively ‘flattened’ on the steep limb towards a major D₁ sinistral transcurrent fault. The angular transection, A, attains a maximum of 15° clockwise which diminishes to <5° at higher strains adjacent to the major fault. Incremental fibre growth in pressure shadows show a two-stage tectonic strain superposition of vertical pure shear followed by sinistral transcurrent simple shear during the development of the clockwise transecting cleavage. Anticlockwise transected folds were influenced by local dextral strike-slip on the southern margins of a rigid terrane. As a regional feature, the clockwise transection is explained by a sinistral transpressive deformation of end-Silurian age.     

The dynamics of mountain erosion: Cirque growth slows as landscapes age

Glacial cirques are widely used palaeoenvironmental indicators, and are key to understanding the role of glaciers in shaping mountain topography. However, notable uncertainty persists regarding the rate and timing of cirque erosion. In order to address this uncertainty, we analyse the dimensions of 2208 cirques in Britain and Ireland and model ice accumulation to investigate the degree of coupling between glacier occupation times and cirque growth. Results indicate that during the last ~120 ka, cirques were glacier-free for an average of 52.0 ± 21.2 ka (43 ± 18%); occupied by small (largely cirque-confined) glaciers for 16.2 ± 9.9 ka (14 ± 8%); and occupied by large glaciers, including ice sheets, for 51.8 ± 18.6 ka (43 ± 16%). Over the entire Quaternary (i.e. 2.6 Ma), we estimate that cirques were glacier-free for 1.1 ± 0.5 Ma; occupied by small glaciers for 0.3 ± 0.2 Ma; and occupied by large glaciers for 1.1 ± 0.4 Ma. Comparing occupation times to cirque depths, and calculating required erosion rates, reveals that continuous cirque growth during glacier occupation is unlikely. Instead, we propose that cirques attained much of their size during the first occupation of a non-glacially sculpted landscape (perhaps during the timeframe of a single glacial cycle). During subsequent glacier occupations, cirque growth may have slowed considerably, with the highest rates of subglacial erosion focused during periods of marginal (small glacier) glaciation. We propose comparatively slow rates of growth following initial cirque development because a ‘least resistance’ shape is formed, and as cirques deepen, sediment becomes trapped subglacially, partly protecting the bedrock from subsequent erosion. In support of the idea of rapid cirque growth, we present evidence from northern British Columbia, where cirques of comparable size to those in Britain and Ireland developed in less than 140 ka. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.     

Environmental justice as subtext or omission: Examining discourses of anti-incineration campaigning in Ireland

The incineration of waste is a controversial issue marked by a history of opposition from community groups and environmentalists around the globe. Opponents, particularly in the USA, have frequently adopted a discourse of environmental justice to challenge the legitimacy of incineration. In line with these broad geographies of resistance recent proposals to introduce municipal solid waste incinerators in Ireland have sparked a series of opposition campaigns. However an examination of the discourses of resistance adopted by campaigners in one specific site of resistance, the Galway region on the west coast of Ireland, indicates that the vocabulary of environmental justice has not been publicly articulated. This paper investigates this absence of environmental justice in the language of opposition. The research reveals an interwoven set of contingent conditions that conspire to inhibit the adoption of environmental justice discourses in Ireland. However these conditions are not static and a combination of pressures, both within and beyond Ireland, are creating a dynamic context that could promote the emergence of environmental justice discourses in the future.     

Climate-driven trends in mean and high flows from a network of reference stations in Ireland

Abstract

This paper introduces a reference hydrometric network for Ireland and examines the derived flow archive for evidence of climate-driven trends in mean and high river flows. The Mann-Kendall and Theil-Sen tests are applied to eight hydroclimatic indicators for fixed and variable (start and end date) records. Spatial coherence and similarities of trends with rainfall suggest they are climate driven; however, large temporal variability makes it difficult to discern widely-expected anthropogenic climate change signals at this point in time. Trends in summer mean flows and recent winter means are at odds with those expected for anthropogenic climate change. High-flow indicators show strong and persistent positive trends, are less affected by variability and may provide earlier climate change signals than mean flows. The results highlight the caution required in using fixed periods of record for trend analysis, recognizing the trade-off between record length, network density and geographic coverage.

Editor Z.W. Kundzewicz; Associate editor H. Lins

Citation Murphy, C., Harrigan, S., Hall, J., and Wilby, R.L., 2013. Climate-driven trends in mean and high flows from a network of reference stations in Ireland. Hydrological Sciences Journal, 58 (4), 755–772.     

Identifying storm impacts on an embayed, high-energy coastline: examples from western Ireland

Large sections of the western Irish coast are characterised by a highly compartmentalised series of headland-embayment cells in which sand and gravel beaches are backed by large vegetated dune systems. Exposure to modally high-energy swell renders most of these beaches dissipative in character. A mesotidal range (c. 3.5–4.5 m) exists along much of the coast. Analysis of instrumental wind records from three locations permitted the identification of a variety of storm types and the construction of storm catalogues. Few individual storms were recorded at all three stations indicating a lack of regional consistency in storm record. Of the total storms recorded, only a small percentage are potentially damaging (onshore directed) and even fewer span a high tide and thus potentially induce a measurable morphological response at the coast.

Through a combination of historical records, meteorological records, field observations and wave modelling we attempt to assess the impact of storms. Quantifiable records of coastal morphology (maps, air photos and beach profiles) are few in number and do not generally record responses that may be definitely attributed to specific storms. Numerical wave simulations and observations at a variety of sites on the west Irish coast, however, provide insights into instantaneous and medium term (decadal) storm responses in such systems.

We argue that beaches and dunes that are attuned to modally high-energy regimes require extreme storms to cause significant morphological impact. The varying orientation of beaches, a spatially nonuniform storm catalogue and the need for a storm to occur at high water to produce measurable change, impart site-specific storm susceptibility to these embayments. Furthermore, we argue that long-period wave energy attenuation across dissipative shorefaces and beaches reduces coastal response to distant storms whereas short-period, locally generated wind waves are more likely to cause major dune and beach erosion as they arrive at the shoreline unrefracted.

This apparently variable response of beach and dune systems to storm forcing at a decadal scale over a coastline length of 200 km urges caution in generalising regarding regional-scale coastal responses to climatic change.     

A new TOC,Rock-Eval,and carbon isotope record of Lower Jurassic source rocks from the Slyne Basin,offshore Ireland

This paper presents an integrated assessment of total organic carbon, Rock-Eval pyrolysis, carbonate δ¹³C and δ¹⁸O, and total organic carbon δ¹³C record of Upper Sinemurian–Aalenian age from the Slyne Basin (well 18/25-1), offshore Ireland. Total organic carbon (up to 5.2 wt%) and Rock-Eval pyrolysis data highlights the Portree Shale Formation Equivalent (Lower–?Middle Toarcian) as a mature (T_max ∼440 °C) source rock dominated by type II kerogens. This interval is more than 90 m thick.In a previously unexplored paleogeographical domain regarding stable carbon isotopes, the δ¹³C record shows positive values during the Upper Sinemurian, a negative trend followed by a minor positive trend during the uppermost Sinemurian–Lower Pliensbachian, a negative trend during the lowermost Lower Toarcian, and then the return to more positive δ¹³C values. Despite the biostratigraphic uncertainty, the coarse resolution of the dataset, and the complex assessment of diagenetic effects, we suggest that the δ¹³C record of the studied well records the Raricostatum Zone positive CIE, the Sinemurian-Pliensbachian Boundary Event, and the negative CIE associated with the T-OAE. The T-OAE positive CIE is not clearly defined in the obtained dataset. The slight post T-OAE negative CIE recovery to more positive values and the continuation of a relatively high organic content is coeval with a regional organic matter preservation interval observed in several Northern-European locations.These new datasets and their interpretation add to the understanding of the paleoenvironmental dynamics during the Early–?Middle Jurassic in the Northern European domain and opens new possibilities for hydrocarbon exploration in Ireland's offshore.     

Progress in Integrated Coastal Zone Management (ICZM) in Northern Ireland

The history of development of Integrated Coastal Zone Management (ICZM) in Northern Ireland is described here in the context of European and UK initiatives. The current structures for ICZM in Northern Ireland involve a formal strategy. This involves a number of specific actions in the environmental, social, and economic spheres with specific goals pertaining to integration. The strategy has been agreed by all responsible organisations (both governmental and NGOs), and each action is time-bound and has an identified responsible agency. The Northern Ireland Coastal and Marine Forum (NICMF) which consists of non-governmental members, has the task of monitoring the implementation of the strategy and acting as a catalyst for integration. The strengths of the current structure lie in the presence of an integrating ICZM strategy and the fact that the initiative is government-led in response to the EU Recommendation on ICZM. These provide better levels of sustainability and links to the statutory system of governance compared to the partnership model in Great Britain. Its main weaknesses are: (i) that the NICMF relies on voluntary participation; (ii) linkages between government departments have not been substantially improved; and (iii) weak mechanisms for ensuring goals are achieved.     

BOOK REVIEWS

Book Reviewed in this article: Main Street: Northeastern Oregon: The Founding and Development of Small Towns . Barbara Ruth Bailey . Food Politics: The Regional Conflict . David N. Balaam and Michael J. Carey , eds. The International Economy and Industrial Development: Trade and Investment in the Third World . R. Ballance , J. Ansari and H. Singer . Neighborhoods in Urban America . Ronald H. Bayor , ed. The English Heartland . By Robert Beckinsale and Monica Beckinsale . Regional Dimensions of Industrial Policy . Michael E. Bell and Paul S. Lande , eds. Tension Areas of the World . D. Gordon Bennett , ed. Latin America: an Introductory Survey . B. W. Blouet and O. M. Blouet , eds. Integration and Division: Geographical Perspectives on the Northern Ireland Problem . Frederick W. Boal and J. Neville H. Douglas , eds. Energy and Land Use . Robert W. Burchell and David Listokin , eds. Slopes and Weathering . Michael Clarke and John Small . Alaska's Rural Development . Peter G. Cornwall and Gerald Mc Beath , eds. The Politics of Park Design: A History of Urban Parks in America . Galen Cranz . World Congress on Land Policy, 1980, Proceedings . Matthew Cullen and Sharon Woolery , eds. Oregon Divided: A Regional Geography . Samuel N. Dicken and Emily F. Dicken . Urban Food Marketing and Third World Rural Development . T. Scarlett Epstein . South Africa: Spatial Frameworks for Development . T. J. D. Fair . Institutions and Geographical Patterns . Robin Flowerdew , ed. Industrialization of U.S. Agriculture, An Interpretive Atlas . Howard F. Gregor . Planning Theory: Prospects for the 1980s . Patsy Healy , Glen Mc Dougall and Michael J. Thomas , eds. Neighborhood Mobilization: Redevelopment and Response . Jeffrey R. Henig . The American Urban System: A Geographical Perspective . R. J. Johnston . Climate, History and the Modern World . Hubert H. Lamb . Climate and History: Studies in Past Climates and Their Impact on Man . T. M. L. Wigley , M. J. Ingram and G. Farmer . China: Railways and Agricultural Development, 1875–1935 . Ernest P. Liang . A Desirable Energy Future—A National Perspective . Robert S. Livingston , T. D. Anderson , T. M. Besmann , M. Olszewski , A. M. Perry , and C. D. West . Topothesia: Essays Presented to T. S. Ó Máille . B. S. Mac Aodha , ed. Transportation for the Poor: Research in Rural Mobility . Hal S. Maggied . Land Uses in American Cities . Harold M. Mayer and Charles R. Haves . Industrial Organisation and Location . Philip Mc Dermott and Michael Taylor . Human Adaptability: an Introduction to Ecological Anthropology . Emilio F. Moran . Regional Analysis and the New International Division of Labor . Frank Moulaert and Patricia W. Salinas , eds. The Nuclear War Atlas. Victoriaville, Quebec, Canada : Urbanization and Environmental Quality . Isao Orishimo . The Garden of Eden: The Botanic Garden and the Re-Creation of Paradise . John Prest . Earthfire, The Eruption of Mount St. Helens . Charles Rosenfeld and Robert Cooke . Contest for the South China Sea . Marwyn S. Samuels . The Future of the Wetlands: Assessing Visual-Cultural Values . Richard C. Smardon , ed. Tucson: the Life and Times of An American City. C. L. Sonnichsen . The Geography of Multinationals . Michael Taylor and Nigel Thrift , eds. Impact of Marine Pollution on Society . Virginia Tippie and Dana Kester . Reviving the Industrial City: the Politics of Urban Renewal in Lyon and Birmingham . Jerry A. Webman . Andean Reflections: Letters from Carl O. Sauer While on a South American Trip under a Grant from the Rockefeller Foundation, 1942 . Robert C. West , ed. Cartographic Drawing with Computers . P. Yoeli .     

Environmental applications of magnetometry profiling

Environmental impact assessment is currently a standard procedure for assessing the possible consequences of any particular activity that may cause degradation of the environment. Magnetometry profiling, which involves accurate measurements of the Earth's magnetic field at closely spaced stations is a technique that has a large number of environmental applications that can greatly improve this assessment. The technique has been applied successfully for waste disposal site evaluation, toxic waste detection, assessment of the quality of roadstone before excavations and can provide information that allows subsurface water movement models to be refined. Magnetometry profiling is inexpensive, nondestructive, and a very costeffective method of acquiring useful information about the environment.     

Turbidites from the Clew Bay Complex,Ireland: provenance based on petrography,geochemistry and crustal residence values

The Clew Bay Complex in the Irish Caledonides represents a Caledonian element separating the Irish–Scottish Dalradian to the north from the South Mayo Ordovician arc basins to the south. The petrographic, geochemical and crustal residence characteristics of the Silurian sandstones within the complex are presented. Petrological analysis indicates that the sandstones were derived from a transitional continental provenance, possibly a passive continental margin or the cratonic flank of a foreland basin. Whole rock geochemistry confirms this provenance type and demonstrates the absence of any significant ophiolite detritus. Sm–Nd model ages indicate a possible derivation from Upper Dalradian or Torridonian rocks, although a mixed provenance may also be considered. These data indicate distinct differences between these turbidites and those of the nearby North Galway succession and suggest that the Clew Bay Complex could be regarded as a suspect terrane with respect to at least parts of the South Mayo arc zone. © 1996 John Wiley & Sons, Ltd.