bluuebunny/crossref_metadata_2025_split huggingface dataset:
Basin-floor fans of the Central Tertiary Basin, Spitsbergen: relationship of basin-floor sand-bodies to prograding clinoforms in a structurally active basin
Authors: Crabaugh Jeff P. , Steel Ronald J. 
Published: April 2008

Abstract
Lower Eocene shelf-slope clinoforms are exposed in 1 × 10 km mountainside outcrops in the Central Tertiary Basin, Spitsbergen. Where clinoforms are sand-prone they include a deepwater sand complex. Submarine fans represent an early, basin-floor aggradational phase of clinoform growth, whereas later growth of the same clinoform involves a phase of shelf-margin accretion. Individual fans, within stacked series, can be distinguished when traced towards the slope, where a thickening wedge of mudstones separates successive fan bodies. The sand-prone parts of basin-floor fans are some 15–60 m thick and extend into the basin by up to 10–12 km. The lower levels of any fan consist of ripple- to parallel-laminated thin-bedded turbidites interbedded with some thick-bedded turbidites. This association changes irregularly upwards to a succession dominated by thick beds that are structureless and parallel-laminated. The thin-bedded facies are interpreted as turbidite sheets that formed as channel-mouth sandy lobes, sandy levees and crevasse splays. The erosively based, thick-bedded facies are interpreted as constructional channel-fill sandstones. The shallow channels fed sheet-complexes both laterally and distally. The apparent short basinward extent and longitudinal palaeocurrents for the youngest fans suggest that downslope sediment transport became longitudinally deflected by anticlinal topography once sediment reached the basin floor.
Submarine fans within small basins: examples from the Tertiary of New Zealand
Authors: Zink Christoph , Norris Richard J. 
Published: April 2008

Abstract
This study uses the example of two small sedimentary basins to draw lessons for the stacking patterns of submarine fan facies in restricted basins. The Te Anau and Waiau basins are located in southwest New Zealand. They developed from the Middle Eocene onwards close to and under the direct influence of the evolving Australia-Pacific plate boundary. Although never more than a few tens of kilometres wide, both basins accumulated sedimentary successions more than 6 km thick. We discuss the scale, nature and composition of submarine fans within the basins. Sediment stacking patterns are characterized by rapid lateral and vertical changes within the full range of facies predicted by most submarine fan models. Despite the small basin size, some submarine fans contain sandstone bodies of impressive thickness (50 m) and many kilometres lateral extent. Such bodies of well-sorted, highly permeable sandstone are excellent potential hydrocarbon reservoirs. The occurrence of complete Bouma sequences and well-developed couplets of clastic- and hemipelagic mudstones indicates that such features are not restricted to large-scale fans (covering thousands of square kilometres). Even in small sedimentary basins, submarine fans can develop that show an impressive range of sedimentary facies and architectural elements, commonly described only from their large-scale counterparts.
Reservoir modelling of the Hamitabat Field, Thrace Basin, Turkey: an example of a sand-rich turbidite system
Authors: Conybeare D. M. , Cannon S. , Karaoğuz O. , Uygur E. 
Published: April 2008

Abstract
The inter-montane, fault bounded Thrace Basin of northwestern Turkey is one of the largest Tertiary sedimentary basins in Turkey. Tertiary sedimentation within the basin comprises interbedded fine- to coarse-grained clastics from a variety of depositional environments, muddy carbonates with local reef developments, and tuff horizons. A thick pile of Quaternary alluvial deposits overlies this marine-dominated succession. Accommodation space, and hence sedimentation, has been influenced by the structural history of the basin, reflecting the active compressional setting adjacent to the North Anatolian Fault System. The Hamitabat Field, located towards the northern basin margin, is the largest developed gas field in the Thrace Basin. The trapping mechanism is by an anticlinal structure bounded to the north by a northwest-southeast striking reverse fault and to the south by a set of antithetic normal faults with a general east-west strike orientation. The main reservoir is the middle to upper Eocene Hamitabat Formation, comprising sandstones deposited by episodic gravity flow events in a shallow marine shelf to slope environment, with sediment sourced from fluvial/deltaic systems to the north and northeast. Correlation, based mainly on upward-fining cyclical successions, indicates lobate depositional geometries and topographic control on sediment dispersal (compensation). Progradational shallow marine sandstones, which infill earlier topography, overlie the turbidite succession. A three-dimensional geocellular reservoir model of the field, based on well and seismic data, has been constructed. The model has been subdivided on the basis of the stratigraphical correlation and populated with facies objects with dimensions based on analogue data. These facies have then been populated with petrophysical parameters. The model has been upscaled and simulated fluid flow through the modelled volume has been compared with the production history. This history matching provides an opportunity to assess and refine the model and to determine a strategy for future field development.
Late Carboniferous-Permian of NW Europe: an introduction to a new regional map
Authors: Heeremans Michel , Faleide Jan I. , Larsen Bjørn T. 
Published: April 2008

Abstract
The Carboniferous-Permian evolution of NW Europe has recently been the focus of an EC-funded Training and Mobility of Researchers (TMR) project ‘Permo-Carboniferous-Rifting in Europe’ (PCR). One of the main goals of this project was to produce a new map for this time period showing the distribution of Late Carboniferous-Early Permian (Lower Rotliegend) volcanics, dykes and sills, and the extent of the tectonic structures of the Early-Late Permian (Upper Rotliegend) sedimentary basins (better known as the Southern and Northern Permian Basins). In order to produce this map, an overview of all the available literature was made. The new map was completed based on our own interpretations from seismic and borehole data. Unpublished data were available through industrial partners associated with the PCR project.
Late Carboniferous-Permian tectonics and magmatic activity in the Skagerrak, Kattegat and the North Sea
Authors: Heeremans Michel , Faleide Jan Inge 
Published: April 2008

Abstract
This study focuses on Late Carboniferous-Permian tectonics and related magmatic activity in NW Europe, and specifically in the Skagerrak, Kattegat and North Sea areas. Special attention is paid to the distribution of intrusives and extrusives in relation to rift-wrench geometries. A large database consisting of seismic and well data has been assembled and analysed to constrain these objectives. The continuation of the Oslo Graben into the Skagerrak has been a starting point for this regional study. Rift structures (with characteristic half-graben geometries) and the distribution of magmatic rocks (intrusives and extrusives) were mapped using integrated analyses of seismic and potential field data. For the analysis of the Sorgenfrei-Tornquist Zone and the North Sea, seismic and well data were used. The rift structures in the Skagerrak can be linked with extensional structures in the Sorgenfrei-Tornquist Zone in which similar fault geometries have been observed. Both in the Skagerrak and in the Kattegat, lava sequences were erupted that generally parallel the underlying Lower Palaeozoic strata. This volcanic episode, therefore, pre-dates main fault movements and the development of half-grabens filled with Permian volcaniclastic material. Upper Carboniferous-Lower Permian extrusives and intrusives have also been found in wells in the Kattegat, Jutland and the North Sea (Horn and Central grabens). Especially in the latter area, the dense seismic and well coverage has allowed us to map out similar Upper Palaeozoic geometries, although the presence of salt often conceals the seismic image of the underlying strata and structures. From the results, it is assumed that the pre-Jurassic structures below large parts of the Norwegian-Danish Basin and northwards into the Stord Basin on the Horda Platform belong to the same tectonic system.
Geochemistry and mineralogy of Rotliegend metavolcanic mafic rocks from Poland: pervasive low-grade metamorphism versus parent rock signature
Authors: Dubińska Elżbieta , Bylina Paweł , Bagiński Bogusław , Kaproón Grzegorz , Kozłowski Andrzej 
Published: April 2008

Abstract

Permian volcanic rocks from the Gorzów Wielkopolski region (NW Poland), although pervasively altered by low-grade metamorphism, still preserve the geochemical characteristics of continental mafic volcanic rocks formed by partial melting of an enriched mantle source. The metamorphic assemblage comprises corrensite, pumpellyite, laumontite, quartz and chalcedony, albite, calcite and solid bitumen (major components). Petrological studies combined with microthermometric determinations indicate a low-pressure zeolite-greenschist-facies transitional zone metamorphic grade with a clockwise (pressure-temperature)
P-T
path: earliest event 140–210 °C and 630–760 bar; metamorphic peak 220–300 °C and 950 bar; youngest episode:
T
⩾ 130 °C and 630–760 bar.

The metamorphism of the Rotliegend volcanic rocks is generally ascribed to penetration of upwelling fluids released from clastic rocks underlying the extrusive Permian unit. However, the ubiquitous occurrence of anhydrite in the altered volcanic rocks suggests an influence of pore water from the overlying Zechstein evaporite sequence. The source of metamorphic heat can be tentatively assigned to abnormal heat flow and/or exothermic reactions during magmatic mineral alteration processes. Dating of metamorphism in neighbouring areas suggests an Upper Jurassic thermal event related to the upwelling of a mantle diapir during the initiation and early evolution of the North Atlantic rift.
Carboniferous-Permian mafic magmatism in the Variscan belt of Spain and France: implications for mantle sources
Authors: Perini G. , Cebria J. M. , Lopez-Ruiz J. , Doblas M. 
Published: April 2008

Abstract
Carboniferous-Permian magmatism in the Spanish Central System, Iberian Ranges, Cantabrian Chain, Pyrenees (Maladeta plutonic complex) and the French Massif Central includes a range of mafic calc-alkaline and shoshonitic rock types, as well as amphibole-bearing lamprophyres (spessartites) and minor alkaline lamprophyres (camptonites). Subalkaline basalts with intermediate characteristics between enriched mid-ocean ridge basalts (E-MORB) and the mafic calc-alkaline rocks also occur in the Pyrenees (Panticosa, Cinco Villas and La Rhune). The incompatible trace-element characteristics of the least differentiated subalkaline rocks and lamprophyres indicate that variably enriched mantle sources were involved in their genesis. High large ion lithophile element/high-field-strength element (LILE/HFSE), light rare earth element (LREE) HFSE and low Ce/Pb ratios in the calc-alkaline and shoshonitic rocks require either assimilation of crustal rocks plus fractional crystallization (AFC) of the parental mafic magmas or melting of a previously subduction-modified mantle source. In the Cantabrian Chain and the Massif Central, melting of a subduction-modified mantle source seems more likely. In the Central System, Iberian Ranges and Maladeta area the lack of any evidence for a contemporaneous subduction system suggests that AFC processes were more likely to be responsible for the crustal signature of the magmas. The alkaline camptonites from the Central System were generated from an enriched mantle source, which had lower LREE/HFSE and LILE/HFSE ratios than the source of the older calc-alkaline magmas from the same area. The incompatible trace-element patterns and ratios (e.g., Y/Nb, Zr/Nb) of the subalkaline basalts from Panticosa, Cinco Villas and La Rhune suggest that they were generated from similar parent magmas, formed by mixing of partial melts of an asthenospheric source and a crustal component.
Shear zones in the upper mantle: evidence from alpine- and ophiolite-type peridotite massifs
Authors: Dijkstra Arjan H. , Drury Martyn R. , Vissers Reinoud L. M. , Newman Julie , Van Roermund Herman L. M. 
Published: April 2008

Abstract
There is abundant field and microstructural evidence for localization of deformation in alpine- and ophiolite-type mantle massifs. On the basis of field relationships and microstructures we recognize two types of tectonite shear zones (medium- to coarse- and fine-grained), as well as two types of mylonitic shear zones (anhydrous and hydrous peridotite mylonites). In tectonite shear zones, softening processes responsible for localization are probably melt-related weakening in the medium to coarse tectonites and a change in limiting slip system in the fine-grained tectonites. In peridotite mylonites, the most likely cause for softening and localization is a change in dominant deformation mechanism from dislocation to grain size sensitive creep. Microstructural and petrological study of mylonite rocks reveals that reactions, either continuous net-transfer reactions (anhydrous and hydrous) or melt-rock reactions, play a key role in the formation of fine-grained material that promotes grain size sensitive creep. These reactions occur over a broad range of pressure-temperature conditions encompassing a large part of the lithospheric upper mantle. We conclude that mantle shear zones are widespread and that they reduce the (bulk) strength of the lithosphere significantly.
Insights from the Ocean Drilling Program on shear and fluid-flow at the mega-faults between actively converging plates
Authors: Maltman Alex , Vannucchi Paola 
Published: April 2008

Abstract
The mega-faults between actively converging plates have recently been penetrated by the Ocean Drilling Program at three plate margins: Barbados, Costa Rica and Nankai. Cores, downhole instrumentation and detailed seismic imagery provide data which may be helpful in interpreting ancient examples of shear zones. The mega-faults, developed in poorly lithified sediments, separate major lithospheric plates yet are merely tens of metres in thickness. They respond to ongoing strain by intensifying inwards rather than propagating outward splays and can grow thinner because of continuing compaction. Surprisingly, lithological influence on the localization of fault propagation seems slight, but lithology determines the deformation style within the faults. The resulting structures show asymmetric distributions within the zones but, in these flat-lying structures, tend to show a downward increase in strain. Upper margins are typically gradational whereas lower boundaries can be strikingly abrupt. The fluid-transport behaviours are complex. In some situations the horizontal flux is very diffuse but centred around the fault. Some faults can efficiently channelize fluids — for distances of tens of kilometres — while at the same curbing flow across them. The fluid transport is clearly episodic and heterogeneous. Fingers of pressured fluid migrate within the fault zone, in patterns that constantly change through time.
Geometric and kinematic analysis of a transpression terrane boundary: Minas fault system, Nova Scotia, Canada
Authors: Macinnes E. A. , White J. C. 
Published: April 2008

Abstract
The Minas fault system is an ENE-WSW trending transpressional boundary between the Appalachian Meguma and Avalon tectono-stratigraphic terranes of Nova Scotia, Canada. Along this boundary there is large-scale partitioning of deformation into distinct external (contractional) and internal (shear) zones. With the increase in strain from external to internal zones there is progressive localization of deformation, culminating in the discrete shear band domain. Deformation has produced materially, temporally and spatially distinct folds and faults throughout the fault system history. Ductile structures are generally composite features derived from multiple transposition of pre-existing layers. The partitioning of deformation found amongst fault rock units can in turn be associated with contrasting deformation micromechanisms. The distinctive variation in mechanical response and microstructures provides an insight into the role of localization, partitioning and distribution of deformation. Kinematic analysis has demonstrated that the Minas fault system segment examined here is a thinning deformation zone, in which strain is accommodated within progressively narrower volumes of rock. Deformation can be summarized as a broad, initially diffuse zone of triclinic transpression that has evolved, with the accumulation of finite strain, into zones of distinct structural style and variation in finite strain. It is not possible to demarcate ‘deformed shear zone’ and ‘undeformed host rocks’. Instead, the Minas fault system is described in terms of discontinuous transitions in finite strain and deformation style within a large scale movement picture.
Constraints on kinematics and strain from feldspar porphyroclast populations
Authors: Giorgis Scott , Tikoff Basil 
Published: April 2008

Abstract
We develop a method for constraining the kinematics and finite strain of deformation in shear zones based on a three-dimensional numerical model of the rotation populations of rigid clasts. The results of the model are characterized in terms of a fabric ellipsoid, which is directly measurable from field data. Fabric ellipsoids measured from populations of prolate clasts have anisotropies that increase steadily and plateau; the shape of the fabric ellipsoid becomes increasingly more prolate with progressive deformation. The behaviour of populations of oblate clasts is much more complex because the stability of individual oblate clasts depends on their aspect ratio and the vorticity of deformation. Populations of oblate clasts may produce fabric ellipsoids with oscillating anisotropies and shapes if their aspect ratio is low enough for a continuous rotation. For either prolate or oblate clasts, the maximum anisotropy that a fabric ellipsoid will reach is governed by the aspect ratio of the individual clasts of that population. The theoretical maximum anisotropy is achieved when all of the clasts are perfectly aligned. The shape of the fabric ellipsoid, in conjuncture with the anisotropy, can be used to constrain the vorticity and finite strain of deformation.
The numerical model suggests that there is no consistent relationship between the asymmetrical orientation of a population of rigid markers and the simple shear component of deformation. Therefore, the asymmetrical alignment of a population of porphyroclasts is not a reliable shear sense indicator. Additionally, there is no direct correlation between the fabric ellipsoid and the strain ellipsoid.
Model results are applied to shape preferred orientation data collected from a feldspar megacrystic granite in the western Idaho shear zone (USA). Three-dimensional fabric ellipsoids are calculated from two-dimensional sectional measurements of oblate-shaped, unmantled, potassium feldspar porphyroclasts. Comparison of these data with the results of the numerical model suggests that transpressional deformation had an intermediate angle of oblique convergence (30°–60°). This implies that deformation in the western Idaho shear zone was characterized by a large component of convergent motion.
Brittle-ductile shear zone evolution and fault initiation in limestones, Monte Cugnone (Lucania), southern Apennines, Italy
Authors: Mazzoli S. , Invernizzi C. , Marchegiani L. , Mattioni L. , Cello G. 
Published: April 2008

Abstract
The processes of brittle-ductile shear zone evolution and fault initiation by the coalescence of en echelon arrays of tensile cracks are quantitatively analysed in terms of displacement and temperature conditions at which they took place in very low-grade, well bedded micritic limestones from the southern Apennines, Italy. Three different types of structures are distinguished: (i) conjugate arrays of en echelon, calcite-filled tension gashes, showing extensional shear offsets; (ii) en echelon vein arrays showing incipient development of discontinuous shear-parallel fractures cutting through the tension gashes; and (iii) faulted vein arrays, in which vein array breaching by a continuous, discrete normal fault has occurred. Fluid inclusion microthermometry from vein calcite sampled from the different sets of structures (i) to (iii) above indicates that environmental conditions remained roughly constant during the different stages of vein array evolution and fault development, with average homogenization temperatures from primary fluid inclusions being in the range 130–140°C. Our results show how displacement accumulation and shear strain essentially control vein array evolution by rotation of en echelon tension gashes, fracture linkage and, eventually, fault nucleation, at approximately constant temperature.
Bath thermal waters: 400 years in the history of geochemistry and hydrogeology
Authors: Edmunds W. Mike 
Published: April 2008

Abstract
The importance of the Bath thermal springs in the development of science over some 400 years is explored. Several references to the springs from Saxon times and the Middle Ages give qualitative information of interest for the present day. The springs have drawn some of the most famous philosophers and scientists to test new theories and develop hypotheses on the nature of matter and to develop early ideas in the chemical and geological sciences. Theories on the hydrological cycle and on hydrogeology were tested and the springs have a long history as a site for discoveries in chemistry and natural radioactivity. Interest in the springs continues to the present day. Whilst our knowledge of the origin of the water, the heat, the detailed chemistry and other properties has been resolved, some questions still remain for the attention of future generations and for the application of advancing scientific methods.
The Scottish hydropathic establishments and their use of groundwater
Authors: Spence Iain , Robins Nick 
Published: April 2008

Abstract
Scotland today has a plentiful supply of drinking water derived from upland gathering grounds, but groundwater supplied all of its major towns and cities in the past. Pollution of many of the old groundwater sources, as well as the atmosphere, by the massive industrial boom of the mid nineteenth century in central Scptland led to the development of hydropathic establishments to dispense the ‘water cure’. Most drew on fresh and pure groundwater sources, and the establishments continued to be a popular source of medical care until the early part of the twentieth century. The groundwater sources were characterized by weak to moderate mineralization unlike the strongly mineralised waters typical of the more traditional spa resorts. A small part of the hydropathic legacy remains in use until this day
Stevenson Buchan (1907–1996): field geologist, hydrogeologist and administrator
Authors: Gray D. A. , Mather J. D. 
Published: April 2008

Abstract
Stevenson Buchan, a Scot educated at Aberdeen University, joined the Geological Survey of Great Britain in 1931. Assigned to the Southern District Unit he became involved in hydrogeology when he revised the 6-inch to the mile maps of Greater London. This led to the publication of a memoir on the water supply of the County of London in 1938. During the war he was involved in the search for water and coal. Appointed Head of a new Water Department when hostilities ceased he was given responsibility for overseeing the statutory obligations placed on the Survey by recent Water Acts. He developed around him a group of able colleagues creating the first groundwater research group of any size in the UK. Promoted to Assistant Director in 1960, he was very active internationally and in his role as an enabler and administrator played an important role in the development of hydrogeology in the UK.