bluuebunny/crossref_metadata_2025_split huggingface dataset:
Review of North Sea Basin development
Authors: KENT P. E. 
Published: December 2007

The large amount of data now available on the North Sea stratigraphy, and on the history of the positive structures which form the sites of the oilfields, provides a basis for a review of basin development.
The area was initially occupied by two inter-cratonic basins: the Northern Basin had a Devonian ancestor; the Southern Basin dates back at least to the Carboniferous. During the Permian and Trias broad intercratonic subsidence continued in the south, but rifting developed across the separating Mid North Sea High and in the Northern Basin. Rifting (taphrogenic) control of subsidence became widely dominant through the Jurassic and lower Cretaceous, dying away in the upper Cretaceous, with major subsidence in the Viking Graben in the Northern Basin and in a series of narrow troughs in the south. No opening of the crust was associated with the central rifting: deep penetrations have encountered Devonian or Precambdan in the rift floor. For the most part the upper Cretaceous sagged into the earlier depressions with minor faulting only, but in the south inversion of the troughs took place in late Cretaceous and early Tertiary times; this may have had a compressional (orogenic) cause.
The Tertiary basin developed as a single, relatively simple synclinal subsidence of the whole North Sea area, centred on the main rift system but showing an absence of fault-control.
Interruptions in deposition on the individual structural high areas show wide correspondence in the North Sea. Except for a major late Triassic movement limited to the Netherlands and adjoining areas they show also close relation to those in Britain. The most notable are early middle Jurassic, early upper Jurassic and end Jurassic/lower Cretaceous. These produced erosional phases even in the deeper parts of the basin. They were entirely of epeirogenic type.
Halokinetic movements of Permian salt produced many local complications (especially in the Southern North Sea Basin) with consequent structural and stratigraphical anomalies from the middle Trias onwards.
Stratigraphical analysis of island arc—continental margin collision in eastern Indonesia
Authors: CARTER D. J. , AUDLEY-CHARLES M. G. , BARBER A. J. 
Published: December 2007

Eastern Indonesia is a sinuous plate margin interpreted as a collision between the northern margin of the Australian continent and an Asian island arc. Detailed stratigraphical analysis of the collision zone in Timor reveals that pre-Pliocene deformation phases affected members of the allochthon before they were overthrust together onto the Australian margin in the middle Pliocene. The Australian facies para-autochthon below the thrust sheets was not involved in these pre-Pliocene deformations. The distinction within the collision zone of elements having different structural histories and opposite facies polarity permits identification of the plate margin which has been overthrust and folded after the initial collision.
The lowest thrust sheet emplaced in Timor and other islands of the Outer Banda Arc appears to be part of an Asian outer arc ridge overthrust by fragments of a continental margin metamorphic basement and volcanic-sedimentary cover.
Stratigraphical studies provide the basis for an explanation of the origin, transport and emplacement of a major olistostrome, for the sequence of allochthonous elements emplaced on the underthrusting continental margin and for post-collision deformation phases in the arc. A speculative model interprets a progressive Mio-Pliocene collision between the Australian margin and an island arc migrating away from SE. Asia by spreading of the marginal-type Banda Sea. The Asian arc was underthrust by the Australian continental margin but buoyancy probably restricted the process to overthrusting slivers of rocks from the trench and trench-arc gap. This model could be tested by seismic and magnetic studies of the Banda Sea region.
The Indonesian
Textures and fabrics in rocks
Authors: McCLAY K. 
Published: December 2007

In the petrological context the term 'fabric' denotes both preferred orientations in populations of crystal grains (metallurgists call this texture) and the shapes and mutual dispositions of matrix grains and subsidiary phases (what metallurgists term morphology). Geologists and metallurgists are often concerned with the fabrics which arise from mechanical deformation of materials and the resultant recrystallization when the temperature is high enough.
Recent research into rock fabrics has increasingly involved metallurgical techniques and theories. In particular Transmission Electron Microscopy (TEM) and X-ray texture goniometry have been widely applied. By drawing analogies with metallurgical phenomena, geologists are better able to understand de-formation mechanisms and the textures produced in rocks. Therefore this meeting was organized to bring geologists and metallurgists together in order to foster a multidisciplinary approach to problems of deformation and textures in rocks.
Two leading metallurgists were invited to give reviews of current thinking on deformation textures and recrystallization textures in metals. Dr I. Dillamore (British Steel Corporation, Sheffield) outlined the development of preferred orientations in deformed metals. He showed that the orientation distribution found in deformed face centred (f.c.c.) and body centred (b.c.c.) cubic metals could be explained by mathematical models which take account of the intracrystalline slip systems and shape change for each grain in a polycrystalline aggregate during plastic deformation. However, in the study of deformed metals, the deformation history and material properties are relatively well known com- pared with those for rocks and minerals but it is clear that these modelling techniques will be
Thermal convection
Authors: ELDER J. W. 
Published: December 2007

The definition and specification of a convective system is outlined. For example for a global system we have: very small Reynolds number (slow ‘viscous’ flow); very large Prandtl number (heat transfer independent of inertial effects); large Peclet numbers (advection dominant in forced convection); very large Rayleigh number (free convection strong and turbulent).
The very wide range and type of convective systems is briefly described. These include systems ranging from the macro-geological scale to small-scale systems such as found in multilayered intrusions.
Clay mineral diagenesis and oil migration in the Middle Jurassic Brent Sand Formation
Authors: Hancock N. J. , Taylor A. M. 
Published: December 2007

Authigenic clay minerals, in an almost complete sequence of oil-saturated Brent Sand from an oilfield in the Viking Graben in the northern North Sea, show a transition from kaolinite in the upper part into illite in the basal part of the reservoir; replacement textures indicate that the illite has replaced kaolinite.
After early kaolinite formation, it is suggested that illite diagenesis took place synchronously with oil migration, and that the progressive extension of oil saturation down through the reservoir terminated diagenetic processes. Early diagenetic stages are thus 'frozen' and preserved in the upper part of the reservoir.
Continental growth, island arc accretion and the nature of the lower crust—a reply to S. R. Taylor & S. M. McLennan
Authors: Tarney J. , Windley B. F. 
Published: December 2007

It commonly happens that the less factual information we have on a problem, the more argument is generated. The lower crust is no exception. In fact the main thrust of our review paper on the lower crust was to demonstrate just how little factual data was available on which to construct reliable models for rustal growth, but that the data which was available (largely on Precambrian lower crustal granulites) did not fully support popular concepts that the lower continental crust is predominantly made up of cumulates or the refractory residues from partial melting. We did not set out to criticize Taylor's andesitic model for crustal growth directly, although in view of the important role the model has played over the last decade we could not avoid referring to it. Taylor & McLennan's defence of the andesite model, coupled with their critique of our own paper, nevertheless behoves us to comment on the andesite model both in relation to their specific points and in relation to our further observations since the paper was written.
With the andesite model there are basically three components to the equation: island arc = upper crust + lower crust. Knowledge of the geochemical characteristics of each is vital in order to test whether the equation will balance. Of the three, only the upper crust composition is known sufficiently well, and as far as the mean rare-earth distribution is concerned it can be approximated by the average sedimentary pattern given by Taylor (1977). There is much less
The seventh UK Geophysical Assembly
Authors: Khan M. A. , Maguire P. K. H. , Hill I. A. 
Published: December 2007

Report of the seventh annual UK Geophysical Assembly held at the University of Leicester from the 11–14 April 1983.

The seventh annual UK Geophysical Assembly on 11–14 April 1983 was sponsored by the Geological Society, London and the Royal Astronomical Society, who also published the abstracts of the 108 papers in the April issue of the Geophysical Journal (vol. 73). It included the Bullerwell lecture on 'Seismic stratigraphy and the evaluation of depositional sequences and fades' by P. Vail of Exxon, in which he demonstrated how depositional environments and facies can be predicted from seismic data through an orderly approach to the interpretation of seismic reflections. A. H. Cook (Univ. Cambridge) gave a second invited lecture on 'The physics of matter at high pressures in planetary interiors'. At high pressures hydrogen will become metallic, melting behaviour will be affected and electrical properties altered. He discussed their implications for our understanding of the structure of the planets and of the physics of condensed matter. B. F. Windley (Univ. Leicester) gave the third invited lecture on 'The tectonic evolution of the Himalayas', which is the subject of multidisciplinary study by a number of international groups at present.
The meeting was attended by over 200 geophysicists and graduate students from universities in the UK and Ireland and from industry. Three parallel sessions were held each day and were supplemented by about 30 research and commercial exhibits. The sessions comprised talks on lunar studies and geochronology; continental and oceanic structure; earth magnetism; earthquake and
A petrogenetic grid for pelites in the Ballachulish and other Scottish thermal aureoles
Authors: Pattison D. , Harte B. 
Published: December 2007

The Ballachulish ‘Granite’ is a composite Devonian intrusive complex surrounded by a distinctive thermal aureole developed in regionally deformed and metamorphosed Dalradian sediments on the W coast of Scotland. The most abundant rocks in the aureole are pelites, which show a progression of assemblages from quartz–muscovite–chlorite up to a variety of high-grade assemblages involving combinations of cordierite, corundum, spinel and, rarely, hypersthene and garnet.
Metamorphic zones have been mapped around the granite, which are defined by the following reactions going upgrade:

Mu
+
Chl
+
Q
=
Cd
+
Bi
+
V

{

Mu
+
Bi
+
Q
=
Cd
+
Kf
+
V

or

Mu
+
Cd
=
Q
+
Bi
+
As
+
V

Mu
+
Q
=
As
+
Kf
+
V

{

Q
+
Bi
+
As
=
Cd
+
Kf
+
V

or

Mu
+
Cd
=
Bi
+
As
+
Kf
+
V

Mu
=
Cor
+
Kf
+
V

Bi
+
As
=
Cor
+
Kf
+
Cd
+
V

The restricted occurrences of assemblages involving spinel, hypersthene and garnet do not allow higher grade zones to be mapped. Variations in the reaction sequence as a consequence of bulk compositional factors, in particular the development of quartz-bearing versus quartz-absent assemblages, are described.

Details of the mineral assemblages from Ballachulish are combined with high-grade assemblage data from the Belhelvie, Lochnagar and Comrie aureoles to construct a comprehensive schematic petrogenetic grid. The grid involves the minerals quartz, chlorite, muscovite, biotite, cordierite, alumino-silicate, K-feldspar, corundum, spinel, hypersthene and garnet, whose assemblage relationships are modelled in the system K
2
O-FeO-MgO-Al
2
O
3
-SiO
2
-H
2
O (KFMASH).
Isotopic dating in metamorphic belts
Authors: Cliff R. A. 
Published: December 2007

Isotopic dating in metamorphic rocks is concerned with the timing of processes whose operation is controlled by continually changing physical conditions. Of these, temperature has a pervasive influence and the use of physical models to elucidate the ways in which temperature is likely to vary is briefly reviewed.
The central concept of closure temperature is critically discussed and quantitative estimates for biotite and hornblende are evaluated, in order to illustrate the factors which control closure temperatures and limit their application in practice. The possibility of dating crystallization using minerals which crystallize below their respective closure temperatures is examined, taking examples involving K-Ar, Rb-Sr, Sm-Nd and U-Pb analyses. The indirect dating of metamorphism via structurally dated plutons is briefly considered, and the problems of interpreting both discordant U-Pb zircon ages and Rb-Sr whole rock isochrons in metamorphosed granites are discussed. The value of near-concordant zircon ages is emphasized. The extent of isotopic equilibration during metamorphism, specifically of Sr-isotopes in metasediments, is shown not to be a simple function of metamorphic grade. The flow of fluids produced by metamorphic reactions appears to be crucial and there is a potential for dating metamorphism using whole rock samples where such flow can he demonstrated independently. The concluding discussion briefly examines existing data for the Dalradian and indicates the potential for further progress using both well-established and novel approaches.
Magnetic studies of the Pendleside Limestone: evidence for remagnetization and late-diagenetic dolomitization during a post-Asbian normal event
Authors: Addison F. T. , Turner P. , Tarling D. H. 
Published: December 2007

The Pendleside Formation, a sequence of bioclastic wackestones and grainstones, has been extensively dolomitized and silicified, especially towards the top and near the axis of the Clitheroe Anticline. Undolomitized limestones are characterized by the presence of magnetite and primary-style magnetic fabrics and an exclusively reversed NRM with mean direction of Dec: =204°; Inc: = —21°. The magnetization is considered to be a depositional/postdepositional remanent magnetization, acquired before any significant alteration of the limestones.
Dolomitized and silicified limestones are characterized by hematite; some silicified limestones show the intermediate state of co-existing hematite and magnetite. These rocks have non-primary style magnetic fabrics and a complex NRM with normal components. The best estimate of this component is Dec: = 22°; Inc; = +20° almost antiparallel to the primary remanence. The magnetization is considered to be a chemical remanent magnetization (CRM) generated during the dolomitization of the Pendleside Formation.
The origin of the dolomitization may be associated with mudrock-dewatering as the sequence was buried. The normal CRM indicates that the remagnetization spanned a post-Asbian normal event, possibly in the Westphalian, coincident with the maximum burial of the Pendleside Formation.
Aluminium mobilization in soils and waters
Authors: BACHE B. W. 
Published: December 2007

The toxicity of dissolved aluminium to many plant and animal species is one of the major deleterious effects of the acidification of the environment. Al mobilization from insoluble forms in minerals and rocks is governed mainly by the pH of the solution surrounding weathering minerals. To a first approximation, the solubility product of gibbsite gives an indication of Al concentrations expected in solution. Secondary silicate minerals such as kaolinite, imogolite and allophane, and sulphate minerals such as alunite, maintain lower Al concentrations in solution than does gibbsite, particularly at pH 5. The cation exchange system of acid soils provides a large reserve of ionic Al, which can be brought into solution when soluble salts percolate through soils. Ligands such as fluoride and organic anions, which form soluble Al complexes, combine with much of the Al in solution when they are present in suitable concentrations, and therefore maintain higher concentrations of Al than might be expected from mineral solubility equilibria, particularly at pH 5–7.
Slow reactions involving solid phases, and uncertain data for possible Al species present, limit the rigorous application of equilibrium thermodynamics to these systems, but the factors mentioned provide a reasonable understanding of the major features of aluminium mobilization.
Late-Archaean tectonics in the Færingehavn–Tre Brødre area, south of Buksefjorden, southern West Greenland
Authors: FRIEND C. R. L. , NUTMAN A. P. , McGREGOR V. R. 
Published: December 2007

The Færingehavn–Tre Brødre area consists of three distinct terranes tectonically jux-taposed by a previously unrecognized event. Contacts between the terranes are mylonitic shear zones truncating lithological units in adjacent terranes. The terrenes are: (1) Færingehavn terrane, largely composed of early-Archaean Amîtsoq gneiss cut by younger Archaean granitic gneiss defined here as the Sätut gneiss; (2) Tre Brødre terrane comprising mid-Archaean Malene supracrustal rocks, anorthosite complex and polyphase Nûk gneisses; (3) Tasiusarsuaq terrane largely comprising mid-Archaean Nûk gneisses affected by
c.
2800 Ma granulite facies metamorphism. The Tasiusarsuaq terrane is structurally above both the Færingehavn and Tre Brødre terranes which at
c.
2800 Ma experienced a lower grade of metamorphism.

Juxtaposition of the terranes took place between 2800 and 2500 Ma and involved thrusting and crustal thickening. Subsequent re-equilibration involved folding, steeply inclined shear belts, intrusion of synkinematic granitoids under amphibolite facies conditions and retrogression of granulite facies assemblages.
This thrusting post-dates the 2800 Ma granulite facies metamorphism. It is younger and distinct from the thrusting postulated to explain the intercalation of the early-Archaean Amîtsoq gneisses and the mid-Archaean Malene supracrustal rocks, associated with intrusion of the Nûk gneiss precursors described from Godthåbsfjord. The tectonic breaks provide, for the first time, marker horizons which can be used to assess the amount and type of late Archaean deformation in the southern Godthåbsfjord region.
Style, scale and significance of sand bodies in the Northern and Central Belts, southwest Southern Uplands
Authors: KELLING G. , DAVIES P. , HOLROYD J. 
Published: December 2007

Sedimentological and biostratigraphical data from the Rhinns of Galloway and adjacent areas in SW Scotland confirm that deep-water depositional systems consistently operated along, and were sourced from, the northwestern margin of an asymmetrical basin during the late Ordovician and early Silurian, while pelagic facies accumulated simultaneously to the SE, providing a scenario analogous to many modern trench systems.
Most of the observed sedimentological anomalies, with regard to this general model, can be explained within the context of the varied styles of trench-filling depositional systems, briefly reviewed here, and the major stratigraphic and sedimentologic features can be best explained in terms of a geotectonically evolving fore-arc region. Two main phases of development are recognized: (a) Llandeilo-late Ashgill: during this time interval the fore-arc trench region was tectonically juxtaposed against an active continental margin arc. Small- to medium-scale, SE-prograding sand-rich fans were formed within a relatively narrow trench, leading to axial diversion of the fans, initially to NE but later mainly to SW. Simultaneously a coarse volcanilithic sediment apron, flanking the arc, migrated gradually northeastwards, probably in response to relative fault displacement of the arc and trench; (b) Llandovery: during this time interval the fore-arc trench region was dominated by a variety of mainly fan-type depositional systems which were exclusively sourced (at least until the uppermost Llandovery) from the northwestern margin. The juxtaposition of coeval depositional systems differing significantly in sedimentological style and composition strongly suggests that the Llandovery sedimentation in this region occurred in several structurally separated sub-basins within the main trench system.
Magnetostratigraphy of the Lower Cretaceous Vectis Formation (Wealden Group) on the Isle of Wight, Southern England
Authors: KERTH M. , HAILWOOD E. A. 
Published: December 2007

Magnetostratigraphic results are described from two sections within the Lower Cretaceous Vectis Formation (formerly Wealden Shales) of the Isle of Wight, Southern England. The sections are located at Shepherd's Chine and Yaverland, respectively.
In both of these sections a reliably-established reverse polarity magnetozone, herein defined as the Vectis magnetozone, occurs within the Shepherd's Chine Member. This magnetozone has a thickness of some 15 m and its upper boundary is well defined in the Yaverland section but is obscured in the Shepherd's Chine Section due to cliff slumping. The lower boundary is well established in both sections and lies some 15 m above the Barnes High Sandstone Member in the Shepherd's Chine section and 12 m above this unit at Yaverland. This boundary provides a useful chron-stratigraphic datum.
A comparison with established geomagnetic polarity timescales for the Cretaceous indicates that the Vectis magnetozone may be correlated either with Lower Aptian reverse polarity Chron CM-0 or with Lower Barremian Chron CM-1, with the former being the more likely. An important implication of this interpretation is that the base of the Aptian stage, as defined from Tethyan foraminiferal zones, must lie within the Vectis Formation, at least 25-30 m beneath the top of the Shepherd's Chine Member, rather than at the top of this member as hitherto commonly accepted.
Beds characterized by anomalously high intensities of magnetization, which occur at the base of the Vectis Formation and a few metres above the Barnes High Sandstone in the two sections, are tentatively interpreted as having a volcanogenic origin.
Depositional models for two Tertiary coal-bearing sequences in the Powder River Basin, Wyoming, USA
Authors: WARWICK P. D. , STANTON R. W. 
Published: December 2007

Depositional controls on peat-forming environments which produce thick (>10m) coal beds can be inferred from relationships between coal bed geometry, maceral composition and associated lithologies. Study of these relationships within sedimentary sequences associated with the Wyodak-Anderson (Palaeocene) and the Felix (Eocene) sub-bituminous coal beds in the Powder River Basin, Wyoming, USA suggests two modes of fluvially controlled peat accumulation. The Wyodak-Anderson peat is interpreted to have formed in restricted parts of the floodplain that were separated by deposits of contemporaneous, anastomosed channels. The channels and associated sediments maintained their position through time because they were confined by thick deposits of raised Wyodak-Anderson peat. In contrast, the Felix coal bed is interpreted to have formed as a raised but widespread peat on an abandoned platform of meander-belt sands.
The purpose of this paper is to compare and contrast two different fluvial depositional settings that produced anomalously thick (>10m) coal deposits in the intermontane Powder River Basin of Wyoming, USA. These models may be useful as predictive tools for coal exploration and production.