bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hyperthermophilic enzymes: biochemistry and biotechnology
Authors: Cowan Don A. 
Published: April 2008

Abstract
Deep submarine hydrothermal vent habitats have already proved to be rich sources of novel hyperthermophilic micro-organisms, most of which belong to the third super-kingdom, the Archaea. These organisms, many of which survive at temperatures at or above 100°C, contain novel macromolecules and metabolic systems which represent a vast resource for fundamental molecular and physiological studies, and for potential exploitation in biotechnology. The one guaranteed property of enzymes isolated from extremely thermophilic micro-organisms is their thermostability. Resistance to heat denaturation also ensures resistance to a number of other denaturing influences (detergents, organic solvents). This characteristic of hyperthermophilic enzymes is the most likely basis for the development of new biotechnological applications. The ability of thermostable enzymes to function in non-aqueous and mixed-phase solvent systems is a particularly useful property. Only a limited number of hyperthermophilic enzymes have found application in specialist biotechnological applications. Hyperthermophilic DNA polymerases and other DNA-modifying enzymes have already contributed significantly to the development of recombinant DNA technology and gene-based diagnostics. Other hyperthermophilic enzymes have obvious potential in the growing area of biotechnology, whereas more distant but no less exciting possibilities lie in those archaeal enzymes which are wholly novel to these organisms.
Basin inversion in the Gulf of Suez: implications for exploration and development in failed rifts
Authors: Knott S. D. , Beach A. , Welbon A. I. , Brockbank P. J. 
Published: April 2008

Abstract
The Gulf of Suez (Clysmic) rift is a classic and well documented extensional province and has many similarities to the North Sea rift to which it is often compared. New structural mapping and fault analysis in western Sinai have shown that post-rift crustal shortening and inversion occurred across the Gulf of Suez, demonstrated by the presence of reverse faults formed as a result of overturning of normal faults, widespread sub-horizontal hydraulic fractures due to vertical stretching, low-angle thrusting and associated folding in the hangingwalls of normal faults, and steepening of bedding dips adjacent to basement stress risers, in some cases overturning stratigraphy. These features show the effect that superposition of inversion on extensional structures has on the geometry of the bedding in footwalls and hangingwalls. Observations and data from outcrop can be used to assist in the interpretation of similar structural relations in the North Sea, where post-rift contraction is also seen. Recognition of inversion-related structures is important in exploration, appraisal and development of North Sea reservoirs, for example, in estimating palaeobathymetry of Late Jurassic depocentres, in constructing cross-sections for reservoir zonation, and in evaluating fault seal and reservoir compartmentalization. Shortening in the Gulf of Suez occurred immediately after rift failure and was probably a gravity-driven process. Similar processes may have occurred in other failed rifts.
Quantification of Tertiary exhumation from sonic velocity data, Celtic Sea/South-Western Approaches
Authors: Menpes Robert J. , Hillis Richard R. 
Published: April 2008

Abstract
Sonic velocities from the Danian Chalk, the Upper Cretaceous Chalk, the Lower Cretaceous Greensand/Gault Clay, and the Triassic Mercia Mudstone were used to quantify apparent exhumation (i.e. amount of missing section) in the Celtic Sea/South-Western Approaches (southern Irish, south-western United Kingdom, and north-western French continental shelves). Analysis of all four of these stratigraphic units yield similar results. Since it is unlikely that sedimentological and/or diagenetic processes are responsible for similar amounts of overcompaction in the chalks, shaly sandstones and shales analysed, burial at depth greater than that currently observed is the most likely cause of overcompaction (anomalously high velocities). The use of lithologies other than shales in maximum burial-depth/exhumation studies is thus validated. The consistency of results from units of Triassic to Danian age suggests that Tertiary exhumation was of sufficiently great magnitude to mask any earlier Mesozoic periods of exhumation, and that the maximum Mesozoic-Cenozoic burial-depth in the Celtic Sea/South-Western Approaches was attained prior to Tertiary exhumation.
The recognized inversion axes of the Brittany Basin, South-West Channel Basin and North Celtic Sea Basin are highs in apparent exhumation, however highs in apparent exhumation of approximately 1 km also occur in the uninverted St. Mary’s and Plymouth Bay Basins, and on the margins of the Armorican and Cornubian Platforms and the Pembroke Ridge. Tertiary exhumation was regional and not restricted to inversion axes, and thus had a thick-skinned origin. Heterogeneous lithospheric compression is the geodynamic model preferred to account for the regional exhumation of the Celtic Sea/South-Western Approaches. The identification of regional exhumation of approximately 1 km has important implications for modelling thermal maturation in the Celtic Sea/South-Western Approaches, with source rocks previously believed to be immature shown to be potentially mature for oil generation.
When corrected for exhumation, the post-rift sequence in the Celtic Sea/South-Western Approaches area shows relatively little localization over the syn-rift Jurassic-Lower Cretaceous sequence, suggesting that during basin formation, the lower lithosphere, thermal re-equilibration of which controls post-rift subsidence, did not experience localized thinning on the scale of the syn-rift basins.
The inversion history of the northeastern margin of the Broad Fourteens Basin
Authors: Hooper Robert J. , Goh Leng Siang , Dewey Fiona 
Published: April 2008

Abstract
The Broad Fourteens Basin experienced a long and complicated developmental history, involving extension, salt tectonics, inversion and subsidence, that began in the Triassic and continued into the middle Tertiary. Inversion in our study area on the northeast margin of the basin was accommodated not only by backward expulsion of the basin-fill (creating a series of northeast-vergent thrusts and related lobate folds) but also reactivation of basement faults. Restorations indicate that the basin-fill did not behave independently of the basement during inversion. At least 2200 m of inversion-related basement uplift must have occurred at the basin margin in addition to backward expulsion of the basin-fill. The most important factors controlling the final ‘inversion style’ appear to be the pre-inversion structural configuration of the margin and the resolved inversion direction.
Extensional tectonics in the Jeanne d’Arc Basin, offshore Newfoundland: implications for the timing of break-up between Grand Banks and Iberia
Authors: Driscoll Neal W. , Hogg John R. , Christie-Blick Nicholas , Karner Garry D. 
Published: April 2008

Abstract
Using seismic reflection and exploratory well data from the Jeanne d’Arc basin, offshore Newfoundland, we examined the link between unconformity generation and the onset of seafloor spreading between the central Grand Banks and Iberia. A prominent unconformity developed across the entire basin, previously interpreted as a ‘break-up’ unconformity, is reinterpreted as a late Barremian/early Aptian rift-onset unconformity on the basis of the stratal geometry and lithofacies. The rotation and divergence of seismic reflectors above this unconformity attest to differential subsidence documenting an episode of extension and block rotation within the basin at this time. Our seismic sequence analysis suggests that rifting and block rotation continued in the Jeanne d’Arc basin until at least late Aptian/early Albian time.
The onset of seafloor spreading between the central Grand Banks and Iberia is uncertain because of limited marine magnetic and drilling data (ODP & DSDP), and the existence of the Cretaceous magnetic quiet zone along the margin. However, recent studies indicate that magnetic anomaly M0 (118 Ma) is not well resolved north of the Newfoundland Seamounts within the Newfoundland basin and is not present north of the Figueiro fracture zone along the conjugate Iberian margin. This suggests that seafloor spreading between the northern portion of the Newfoundland basin and the northern Iberian margin began after the early Aptian. Given that the cessation of rifting marks the onset of seafloor spreading our seismic sequence analysis indicates that the onset of seafloor spreading in the northern Newfoundland basin, north of the Newfoundland Seamounts, began after late Aptian time.
Thermal histories of Permian and Triassic basins in Britain derived from fission track analysis
Authors: Carter A. , Yelland A. , Bristow C. , Hurford A. J. 
Published: April 2008

Abstract

Permian and Triassic rifting in northern Europe resulted in the deposition and preservation of alluvial sediments within discrete graben structures throughout the UK. The sediments are mostly continental red-bed facies which contain little or no organic materials for vitrinite reflectance palaeotemperature estimation. However, the sandstones commonly contain detrital apatite from which fission track age and track length data can be readily derived, and the elusive low temperature thermal history quantified. Published and new fission track data from over 80 Permian and Triassic sandstones in Britain reveal contrasting thermal histories. Triassic rocks of northwest Scotland have seen only moderate palaeotemperatures (60–75°C), reached during the Mesozoic, in contrast to the Cheshire and Irish Sea Basins which experienced greater maximum palaeotemperatures (80–110°C) during the Late Cretaceous (Lewis
et al.
1992
b
). In southwest England, maximum palaeotemperaturs of 70–80°C (∼95°C in the basin centre at Wytch Farm) were reached during the Lower Cretaceous. The Permian and Triassic sediments of this study indicate that maximum burial is not restricted to the Late Cretaceous and that, in the southwest especially, temperatures peaked much earlier, during the Lower Cretaceous. This implies a significant variation throughout Britain in both Mesozoic cover and its subsequent exhumation.
Dating, correlation and stratigraphy of the Triassic sediments in the West Shetlands area
Authors: Swiecicki T. , Wilcockson P. , Canham A. , Whelan G. , Homann H. 
Published: April 2008

Abstract
Very thick sequences, up to 25 000 ft, of Permo-Triassic sediment are preserved within the Papa and East Solan Basins, in the West Shetlands area. The active margin of this Permo-Triassic basin lay along the West Shetland Spine Fault. Due to severe erosional truncation, the position of the westerly passive margin cannot be delineated. The Triassic basin fill, referred to the Papa Group, has been proven by drilling to be at least 8000 ft thick. A combination of palynological, log and sedimentological analyses have allowed the succession to be informally subdivided into lithostratigraphic units. The oldest, of earliest Triassic age, is the Otter Bank Shale Formation deposited in a coastal/alluvial plain setting. This is gradationally succeeded by the coarse-grained Otter Bank Sandstone Formation comprising sediments derived from the interdigitation of sheetflood, braidplain and aeolian environments of deposition. These represent the initial erosional products derived from the uplifted, rifted basin margin. This major phase of Early Triassic rifting is believed to have taken place during the Scythian. The succeeding Foula Sandstone Formation marks the establishment of predominantly axial braidplain systems, deposited during a period of intermittent but waning tectonic influence during Middle to Late Triassic times. The Papa Group is referred to the New Red Sandstone Supergroup.
Sequences, cycles and other nonsense: are submarine fan models any use in reservoir geology?
Authors: Anderton R. 
Published: April 2008

Abstract
There is no fundamental reason why there should be a relationship between the vertical succession of beds in a submarine fan deposit and their three-dimensional geometry. Parts of some fans behave in such a way that they leave behind sequences that can be used to define bed geometry. However, a significant proportion of the fan sands that are found in hydrocarbon reservoirs were deposited in unstable mid-fan environments that produce chaotic vertical successions. These are best modelled using stochastic techniques.
The liquification and remobilization of sandy sediments
Authors: Nichols Robert J. 
Published: April 2008

Abstract
A number of large, unusually shaped sandbodies have been interpreted from three-dimensional seismic data of hydrocarbon-bearing Tertiary submarine fan deposits of the North Sea. The unusual sandbody shape is considered to have resulted from post-depositional liquification of turbidite deposits. An understanding of liquification processes may therefore be important in delineating reservoir body geometry. The unusual shapes take the form of sheet-like intrusions, either along faults or as dyke and sill complexes, and domes with oversteepened sides. Three processes can cause liquification: (1) fluidization, which results from pore fluid movement; (2) liquefaction, caused by the agitation of grains during cyclic shear stress; and (3) shear liquification which results from the movement of grains during the application of a shear stress across the sandbody. In laboratory experiments each liquification process produces its own style of deformation. Fluid escape and dish structures are produced during fluidization, load structures form during liquefaction, and mass flow structures result from shear liquification. The three liquification processes can interact to create an even greater diversity in deformation style. The active liquification process, or combination of processes, can change in both space and time. In the natural environment it is unlikely that one liquification process will occur independently and therefore most natural liquification must be considered in terms of two or more interactive processes. The large-scale deformation of sandbodies and hence their geometry may vary according to which liquification process or processes are active. In natural systems the sandbody will not deform in isolation from the surrounding material. The rheology of the surrounding material and the nature of the stress field active at the time of deformation will play an important part in controlling the behaviour of the sandbody during remobilization.
Sediment dispersal patterns in a deep marine back-arc basin: evidence from heavy mineral provenance studies
Authors: Browne J. R. , Pirrie D. 
Published: April 2008

Abstract
Heavy mineral provenance studies can aid reservoir description in deep marine depositional systems by providing a clearer understanding of the lateral extent of discrete sediment bodies. In this study the lower Gustav Group (Lagrelius Point, Kotick Point and Whisky Bay formations) of James Ross Island, Antarctica, which was deposited in a deep marine slope-apron-submarine fan complex has been investigated. The Kotick Point and Whisky Bay formations crop out in two separate areas on the west coast of James Ross Island. The provenance of the group has been studied by both standard sandstone petrography and electron microprobe analysis of the heavy minerals’ garnet, pyroxene and Fe-Ti oxides. The sandstones are lithic to arkosic arenites derived from the adjacent Antarctic Peninsula magmatic arc. Although the general source area can be recognized, individual stratigraphical or depositional units cannot be distinguished on the basis of sandstone petrography. However, electron microprobe analyses of the detrital heavy minerals allows a more detailed discrimination of sediment provenance. In particular, analyses of the detrital Fe-Ti oxide minerals show that in the Whisky Bay Formation, the southern outcrop area, contains ilmenite, whilst the northern outcrop area contains titanomagnetite. In conjunction with the available biostratigraphical and palaeocurrent evidence, this can be interpreted in two ways. Firstly, if the two outcrop areas are direct age equivalents then they were derived from separate point sources, and deposited as discrete sediment lobes. Alternatively, if they are not directly time-equivalent, the depositional system may have switched laterally with time, with sediment derived from source rocks of varying composition. Either interpretation has implications for the understanding of the deep marine depositional system. Detrital opaque minerals are commonly source specific and should not be ignored during provenance studies.
Paradigms for the Pilbara
Authors: Trendall Alec F. 
Published: April 2008

Abstract

The Pilbara Craton is a discrete and coherent body of well preserved and exposed early continental crust in the northwestern part of the Australian continent, with a present surface area of about 180 000 km
2
. It has two tectonostratigraphic components: an older ‘basement’ of granite-greenstone terrane, formed between about 3.5 and 2.9 Ga, unconformably overlain by a supracrustal sequence, the Mount Bruce Supergroup, laid down between about 2.8 and 2.4 Ga in the Hamersley Basin. The main body of the craton has retained its integrity since that time, and has undergone only regional uplift, mild metamorphism, and gentle folding. A tendency to interpret the geology of the craton in terms of paradigms, involving a simplistic comparison with other areas thought to be better understood, has impeded the development of independent hypotheses of crustal evolution based on objective integration of observational evidence from within the Pilbara craton itself.
Early Proterozoic mafic dykes in the North Atlantic and Baltic cratons: field setting and chemistry of distinctive dyke swarms
Authors: Bridgwater David , Mengel Flemming , Fryer Brian , Wagner Paul , Hansen Søren Claudius 
Published: April 2008

Abstract

Widespread swarms of basic dykes intruded the Archaean North Atlantic craton (NAC) and the NW Baltic shield between 2.5 and 1.9 Ga. The oldest Mg-rich dykes and sills are 2.4–2.5 Ga and are associated with rift controlled acid and basic magmatism. In SW Greenland the main high-Mg swarms are
c.
2.2 Ga. The high-Mg dykes have high Si, LILE and LREE and are low in Ca, Al, Ti and Nb. Isotopic compositions (Sr, Nd and Pb) demonstrate a high degree of crustal contamination. Individual dykes are remarkably constant in composition but there are large variations between adjacent dykes. Tholeiitic swarms were emplaced at
c.
2.2 Ga in the southern part of the craton in SW and SE Greenland and Labrador. The majority are normal moderately evolved tholeiites with no marked LILE or LREE enrichment, a few c. 2.2 Ga comparatively mafic tholeiitic dykes show a LILE and LREE enrichment. Dense swarms of distinctive Fe-enriched hornblende-bearing tholeiitic dykes (the
c.
2.0 Ga Kangâmiut dykes) intruded the northern part of the NAC in Greenland. Many are composite with intermediate centres. The Kangâmiut dykes were emplaced at depth during shearing in a regional N-S compressional regime and developed metamorphic mineral assemblages at the time of dyke injection. The 1.83 Ga Avayalik dykes from the eastern foreland of the Torngat orogen, northern Labrador show comparable syn-tectonic emplacement and autometamorphic assemblages. Emplacement was controlled by regional sinistral shearing after the first calc-alkaline igneous activity had occurred within the orogen.
The Pleistocene evolution of the Thames and Rhine drainage systems in the southern North Sea Basin
Authors: Bridgland D. R. , D’Olier B. 
Published: April 2008

Abstract
During most of the Middle and Late Pleistocene, global climate was colder than at present. At such times, sea-level was very much lower and the southern North Sea was land, drained by the same rivers that today issue into the sea from Britain and north-west Europe. Evidence from onshore in Britain suggests that the Thames did not drain into the southernmost part of the North Sea Basin until the early Middle Pleistocene; prior to that it flowed across East Anglia and northwards across the area of the present north Norfolk coast. It is thought that the lowland between Kent, East Anglia and the Continent was at this time drained by the ‘Lobourg River’, which arose on the northern flanks of the Wealden ridge and drained northwards into what is now the southern North Sea. The early Medway is thought to have joined this Lobourg River in the area that now lies offshore from southeast Suffolk. It seems that by the early Middle Pleistocene the Thames had adopted this course of the Medway and with it, therefore, the confluence with the Lobourg.
It is widely believed that Anglian/Elsterian ice-sheets caused proglacial ponding in the southern North Sea basin and that a large lake formed, fed by the Thames-Medway and Rhine river systems. It has also been suggested that this lake overflowed to the southwest into the English Channel Basin, breaching the Chalk ridge and initiating a through route via the Strait of Dover, a route that was used by the Rhine-Thames drainage system during all subsequent low-sea-level episodes. Middle and Upper Pleistocene deposits of both the Thames and Rhine systems are preserved in the areas immediately offshore from Britain, The Netherlands and Belgium and can be traced from both sides towards the axial channel of the North Sea Basin, the formation of which was perhaps initiated by the Lobourg River. Although the Rhine’s offshore deposits, in particular, appear to follow a route that heads southwards, towards the Strait of Dover, no sedimentary evidence has yet been found that demonstrates a late Pleistocene fluvial course either through this strait or, conversely, into the North Sea.
Extension of the British landmass: evidence from shelf sediment bodies in the English Channel
Authors: Bellamy Andrew G. 
Published: April 2008

Abstract
Mapping and interpretation of high-resolution shallow seismic and vibrocore sample data from a submerged, infilled valley immediately east of the Owers Bank, at −20 m to −40 m chart datum (CD), eastern English Channel, indicate sediment body formation during multiple cut-and-fill events. Interpretation suggests that these occurred in a combination of diachronous gravel-bed river, peat-land, estuarine and shallow sub-littoral environments with subsequent marine planation (forming ravinement surfaces) and accumulation of a sea-bed sediment veneer. These environments are associated with large-scale relative sea-level and (inferred) climatic changes during the Quaternary which forced subaerial inner continental shelf conditions during cold stages, repeatedly interrupted by interglacial shelf submergence. A model of sediment body formation off the south coast of England, based on the case study findings, shows that subaerial, and not submarine, processes have dominated sedimentary history within present-day, submerged, infilled valleys. Relative to the Quaternary as a whole, global ice-volume is presently unusually low, implying that present eustatic sea-level is unusually high. Subaerial linkage of present-day southern England with the adjacent inner shelf has therefore persisted for most of Quaternary time, with the notion of British insularity applicable to only a relatively small part of the period.