bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peri-collisional extension and the formation of Oman-type ophiolites in the Banda arc and Brooks Range
Authors: Harris R. A. 
Published: April 2008

Abstract
Integration of data from field, geochemistry, and radiometric age investigations of the active Banda arc—Australia collision zone (Banda orogen) and the Jurassic Brooks Range ophiolite provide new constraints for the origin and emplacement of Oman-type ophiolites. These ophiolites are characterized by ultramafic residuals and mafic products that are chemically modified by various degrees of partial melting. The internal structure of the igneous complexes document acute extensional strains. A high temperature metamorphic sole with some continental margin protoliths are locally preserved at the structural base of the massifs. Age relations between the ophiolites, their metamorphic sole, and collisional mountains in which they reside indicate important temporal and spatial associations. Some of these relations are inconsistent with ophiolite genesis in intra-oceanic settings.
Formation of the Savu and Weber basins around the active Banda orogen provide modern analogues of peri-collision extensional processes. These extensional domains are transitional between zones of active supra-subduction zone magmatism (ophiolite genesis) and low-angle overthrusting (ophiolite emplacement). Geochemical data from the volcanic basement of the Savu basin are similar to ‘transitional-type’ ophiolite volcanic suites. Ar/Ar ages, and stratigraphic and structural data from the basin indicate volcanism and forearc extension coincide in time and space with initial collision between promontories of the NW Australian passive margin and the Java trench, suggesting a link between the two processes. Similar age and stratigraphic relations are also documented in the Brooks Range and other Oman-type ophiolites.
Peri-collisional extension opens small SSZ ocean basins that may be obducted during or shortly after they form by progressive convergence at multi-plate boundaries. These processes provide a self-perpetuating mechanism for ophiolite genesis and emplacement that accounts for both the similar and diverse aspects of many ophiolites.
The role of Palaeocene magmatism in the tectonic evolution of the Sea of the Hebrides Basin: implications for basin evolution on the NW Seaboard
Authors: England Richard W. 
Published: April 2008

Abstract
Major, trace element and isotope geochemistry of the magmas of the British Tertiary Volcanic Province suggests they rose through the lithosphere in dykes and ponded as sills at the Moho and within the upper crust. In the Sea of the Hebrides basin a linked system of discrete dyke swarms, sills and normal faults record rapid NE-SW extension at the near surface. The presence of a similar system of dykes and sills within the upper crust and at the Moho could have influenced mechanisms of lithospheric extension by dissipating vertical variations in strain laterally, eliminating space problems associated with depth dependant stretching. The addition of large thicknesses of magma to basins along the NW seaboard would have resulted in local burial, but subsidence would be offset by uplift resulting from isostatic effects and thermal expansion of the lithosphere during melting. Heat loss from rising magma would have a negligible effect on the maturation history of the sediments.
Low-temperature effects of the Skye Tertiary intrusions on Mesozoic sediments in the Sea of Hebrides Basin
Authors: Lewis Cherry L. E. , Carter Andrew , Hurford Anthony J. 
Published: April 2008

Abstract
Fission track analysis of samples from the Sea of Hebrides Basin and surrounding regions demonstrates two very distinct age groups around 50 Ma and 300 Ma, regardless of the stratigraphic age. Apatite fission track results from sediments within 8 km of the Tertiary igneous complex on Skye were totally reset by temperatures >110°C during intrusion of the centres, but now yield ages younger than the granites. Zircon fission track results from the granites also demonstrate ages significantly younger than their hosts. Mean track lengths in apatites of <13.5 µm, and reduced apatite and zircon ages, suggest that temperatures remained elevated throughout the 6 Ma during which intrusive activity occurred, but were hotter within the granite bodies than the surrounding sediments.
Prior to intrusion of the complex, temperatures in the basin sediments presently at outcrop were unlikely to have been higher than 50°C, and beyond the effects of the Tertiary intrusions, age and track length distributions from northern Skye, the Isle of Lewis and the west coast of Scotland illustrate that the area is unlikely to have been buried beneath more than 2 km of sediment at any one time since the end of the Devonian. North of the Highland Boundary Fault, Tertiary uplift and erosion in Scotland is considered to have been between 1–1.5 km. This is consistent with a regional pattern of Tertiary erosion identified across the British Isles, but considerably less than that recognised in Northern England.
The Clare Lineament: a relic transform fault west of Ireland
Authors: Tate Michael P. 
Published: April 2008

Abstract

The Porcupine Seabight Basin is dissected at
c.
51°N by a major ESE-WNW trending structure which separates the Main Porcupine Basin from the Seabight Basin. This structure was initially mapped across the southern boundary of the Rockall Trough, where it was termed the Clare Lineament and interpreted as a Mesozoic precursor to the present-day Charlie Gibbs Fracture Zone. Evidence is presented here for its extension to the eastern margin of the Porcupine Seabight Basin. There it lies to the south of the Iapetus suture zone imaged by deep seismic data west of Ireland, to which it does not appear to be related as had previously been suggested. At the onset of sea-floor spreading during the mid-Cretaceous, the Clare Lineament evolved as an incipient transform fault. It separated volcanism to the north, which produced N–S ridges above attenuated continental crust in the axes of the southern Rockall Trough and Main Porcupine Basin, from the rift-drift transition in the proto-Atlantic rift to the southwest, now occupied by oceanic crust of the Porcupine Abyssal Plain. The Clare Lineament was probably then superseded by the Charlie Gibbs Fracture Zone during the Late Cretaceous.
Synoptic palaeogeography of the Northeast Atlantic Seaway: late Permian to Cretaceous
Authors: Doré A. G. 
Published: April 2008

Abstract
The NE Atlantic rift system was a key element in marine connectivity between the northern (Boreal) and southern (Tethyan) marine realms. Palaeogeographic summary maps in this account emphasize the exploitation of pre-existing basement grain on a regional scale, particularly that of the Caledonian Orogen, in the development of the Mesozoic linked rift systems. Also emphasized are the importance of extension across the rift system during successive tectonic episodes and, as implied by restoration of the stretching, the narrowness of the proto-North Atlantic seaway in the Late Permian — Early Mesozoic.
The palaeogeographic maps document a sequence of tectonic events leading to the break-up of Pangea. Block-faulting in the mid-Permian enabled marine conditions to penetrate southwards from the Boreal Sea to the Zechstein and Bakevillia Seas of NW Europe, although no link with the Tethyan realm can be documented. The Triassic was characterized by intense differential movement and sediment accumulation. Sporadic marine ingressions took place into the NE Atlantic and North Sea basins. However, no throughgoing connection between marine tracts in the Barents Sea and Tethys was established until the Early Jurassic, when a series of transgressions brought widespread marine conditions and faunal unification between north and south. In the Middle Jurassic, regional uplift in the central North Sea, and probably in the NE Atlantic rift system, ran counter to an overall transgressive regime, suggested by regional sea-level curves and by overstepping of the East Greenland and Mid-Norwegian basin margins. These restrictions re-established acute provinciality between the Boreal and Tethyan realms. Marine connections were restored by intense rifting and transgression in the Late Jurassic, but the evolution of a complex seaway with major land barriers in the earliest Cretaceous saw a return of marine provinciality. Transgressions associated with probable ocean floor development to the southwest (Rockall Trough, Hatton-Rockall Basin) and northwest (Canada Basin) of the study area in the Albian and Late Cretaceous finally established an open seaway through the NE Atlantic rift. Massive subsidence in the Faeroes Trough and Mid-Norwegian basins, and dextral shear along the Barents Sea margin, were precursors to final crustal separation in the Early Tertiary.
Decision making under risk in the mining industry: a risk appraisal case study
Authors: Walduck G. P. 
Published: April 2008

Abstract
The concepts of risk and uncertainty in investment are defined and their relevance explained. The nature of the uncertainty of a number of parameters employed in investment appraisal is described. Risk modelling in computer-assisted evaluations using Monte Carlo simulation is illustrated by means of a case study involving a brief and comparatively simple analysis. The study points to the possibility that a superficially attractive investment can become unattractive when risks are assessed, but conditions under which the reverse may be true are pointed out. The importance of results interpretation and presentation is high-lighted.
Waste disposal, data collection and quarry design
Authors: Allington Ruth , Walton Geoffrey 
Published: April 2008

Abstract
This paper outlines important data that must be collected as a basis for successful quarry design. In particular, it focuses on waste materials; how and in what quantities they will arise and why planning for their handling, storage and disposal must be an integral part of the design at all stages. Difficulties that arise when waste is underestimated or ignored are noted and design methods to avoid these pitfalls are described.
A case history of pre-extraction site investigation and quarry design, Cliffe Hill Quarry, Leicestershire
Authors: Barrett W. L. 
Published: April 2008

Abstract
A brief history of the reasons leading up to the initiation of this project is followed by a description of the geographical location and geological significance of the chosen site.
An initial phase of test pitting produced evidence which warranted a follow-up phase of continuous flight auger drilling along existing tracks. This work in turn indicated that serious exploration at great expense was warranted and a relatively powerful, brand new, drilling rig, capable of both coring and drilling through substantial thicknesses of overburden, was purchased. Several years of drilling, much of it on a 50m grid, subsequently proved the existence of a viable quantity of resource beneath an acceptable depth of overburden. Simultaneous testing of the core samples for a range of physical properties (as per BS 812) indicated the materials to be of acceptable quality for the anticipated markets, including rail ballast for high speed tracks. The drilling information was supplemented by a limited amount of geophysical work, mainly employing a shallow seismic refraction technique.
Initial quarry planning studies indicated that a viable reserve could be generated by stripping overburden to a depth of 40 m around the periphery, and a planning application for areas of quarrying and overburden disposal was submitted. After considerable discussion and some modification, permission was granted, subject to a large number of conditions. Phased overburden stripping will ultimately involve several million cubic metres. This site will be subject to a full investigation as required by Section 9 of the Mines & Quarries (Tips) Regulations and this will determine the angles of safety for both the cut slopes and the deposited overburden.
Preliminary configurations for the quarry, in terms of face heights, batter angles and bench widths were determined from geotechnical logging of the cores, the results of which were subsequently augmented by detailed mapping of the early exposures created. Full site investigations were also carried out for the location of load bearing structures.
Development of a field computer data logger and its integration with the DATAMINE mining software
Authors: Onions R. I. , Tweedie J. R. 
Published: April 2008

Abstract
The paper outlines the reasons for, and the development of, a field data logging system for sand and gravel exploration. It covers the selection of hardware and the development of the software which make up the system.
The use of this system by the geologist/drilling assistant in the field as site investigation progresses is described together with the method of producing borehole logs without further keying in of data.
The progress towards integration of data derived from the field computer, laboratory and the MOSS survey system is outlined as is the use of these data by the DATAMINE package for reserve modelling and assessment, and production of resource and working plans. An evaluation of the time and costs saved using this integrated approach to data gathering, storage and processing in the investigation is made.
The aim of the paper is to show how computers can be used in the extractive industry, from the initial stages of on-site logging to the production of final working plans, to reduce the number of points at which errors can be introduced, thus increasing accuracy of reports and reducing the time and costs involved.
The application of DATAMINE in kaolin resource management
Authors: Howe J. H. 
Published: April 2008

Abstract
The computerized reserve evaluation system developed in house for ECCI’s UK kaolin operations served well from 1981 to 1987 but, with an evolving data base and increasingly more sophisticated demands placed upon it, its limitations became ever more apparent.
It was clear that to maintain the system and develop it at the required pace was not feasible. Therefore the decision to replace it with a proprietary system was taken and DATAMINE was installed in July 1988.
The new system has been installed to operate in parallel with the ECLIPSE ground modelling system which has been in operation at ECCI since early 1985 and has made significant impact in the fields of surveying, mapping and of quarry and tip design. At the present time, 900f the Mid Cornwall China Clay region has been mapped using this system and topographic update is readily available in digital format for quick assimilation into DATAMINE, speeding up model construction immeasurably.
The application of DATAMINE is discussed in terms of its role as a tool in resource management and the construction of orebody models for primary kaolin deposits is briefly described. In order that the system could be made more specific to ECCI’s kaolin operations, a series of macros have been developed which essentially customize DATAMINE to ECCI’s specific requirement whilst maintaining total flexibility. These macros are described in broad outline and this serves to illustrate how the system is being applied in this particular situation. The ultimate goal is to provide a comprehensive and flexible overview of ECCI’s kaolin resources in SW England. This overview, coupled with a mineral extraction and debris disposal schedule, is a key component in the cost effective management of ECCI’s mineral business.
The use of three-dimensional surface modelling in the design of mines and quarries
Authors: Norton J. 
Published: April 2008

Abstract
Major changes have occurred in mining practice as a result of the evolution of computer technology. MOSS Systems Limited was one of the first companies to develop and market a system geared to the requirements of mineral extraction operators. The benefits inherent in the use of such a 3D modelling system are described in detail. MOSS analysis techniques can be applied to the 3D model at any stage in the design or subsequent operation of the workings. These techniques include the generation of sections and profiles, volumetric and mass-haul analyses, contouring, and isopachyte analysis. A novel example of the use of MOSS in the optimized design of spoilheap geometry is given.
Coastal upwelling in the modern ocean
Authors: Smith Robert L. 
Published: April 2008

Abstract
During the past decade several major physical oceanographical experiments were performed over the continental margins along the ocean’s eastern boundaries. The studies extended farther seaward than the continental shelf and extended over the seasons. As a result, our understanding of the processes and phenomena associated with coastal upwelling and affecting the ocean farther seaward has increased. The Coastal Ocean Dynamics Experiment investigated the dynamics controlling the currents over a continental shelf exposed to strong upwelling favourable winds; the experiment was more intensive and completely instrumented than any previous shelf experiment. The Coastal Transition Zone experiment investigated the cool ‘filaments’ conspicuous in satellite images of SST off northern California during the coastal upwelling seasons. Associated with the cool filaments are jets along the boundary between the cooler recently upwelled water and the warmer adjacent ocean water; as the jets meander equatorward and offshore (several hundred km), the upwelled water extends over greater distances offshore than previously thought likely. One experiment (SuperCODE) looked at the large alongshore scale, from 35°N to 50°N off the west coast of north America, defined the seasonal cycle, and found that the tendency for subsurface poleward flow over the continental shelf and slope increased at lower latitudes in spite of the increased equatorward mean wind. The ubiquitous poleward currents, usually subsurface over the inner slope and outer shelf, have been observed in all the experiments off the west coasts of the Americas, in spite of equatorward winds. Unlike the jets of the coastal transition zone, the poleward undercurrents are trapped to the continental slope and shelf. The Leeuwin Current Interdisciplinary Experiment took place off Western Australia, the only major eastern boundary without coastal upwelling in spite of strong equatorward winds. The alongshore pressure gradient along the west coast of Australia is large, perhaps because of the free connection to the western Pacific, and dominates the opposing equatorward wind stress, suppressing upwelling and causing poleward flow (the Leeuwin Current) at the surface over the slope and outer shelf.
Variations in the benthic foraminiferal fauna of the Arabian Sea: a response to changes in upwelling intensity?
Authors: Hermelin J. O. R. 
Published: April 2008

Abstract
Results from ODP Leg 117 show that abundance and species composition of the benthic foraminiferal fauna in the northwestern Arabian Sea vary extensively through time. Studies of the Recent faunas from the region show that the distribution of benthic foraminifers is strongly correlated with the depositional environments present, of which some are associated with the OMZ (oxygen minimum zone). The OMZ is a result of strong seasonal upwelling caused by monsoonal winds and the Recent benthic foraminifers that thrive in this specific environment form a characteristic assemblage. Assuming that this relation between this benthic foraminiferal assemblage and OMZ/upwelling conditions were present in the geological past the relative abundance of the species forming that assemblage can be used to reconstruct past changes in the intensity of the monsoonal upwelling and changes in the water circulation pattern in this area.
A deepening of the lower boundary of the OMZ occurred between 6.5 and 3.0 Ma with a maximum at 5.0 Ma (= more intense upwelling ?). After 5.0 Ma, mixing of more oxygenated outflow water originating in the Red Sea weakened the severity of the OMZ in the interval 200 to 500 m in this part of the Arabian Sea. This mixing became more intense with time, as reflected in the benthic foraminiferal fauna, and today there is a pronounced intercalation of oxygenated water at this water depth and a low percentage of the assemblage associated with the OMZ.
Radiolarian microfauna in the northern California Current System: indicators of multiple processes controlling productivity
Authors: Welling Leigh A. , Pisias Nicklas G. , Roelofs Adrienne K. 
Published: April 2008

Abstract
Radiolaria, as other plankton, appear to be highly tuned to specific oceanographic environments. Thus, in a transitional region such as the eastern North Pacific, where many different water masses are mixed, radiolaria provide very sensitive tracers of these water masses and the currents that carry them. We present the first two years of radiolarian results from the Multitracers sediment trap study across the northern California Current System. Three moorings, positioned along a transect at approximately 130, 280 and 650 km from the coast, sample a wide variety of oceanographic conditions both spatially and temporally. Selected species or species groups are presented along with hydrographic data from the region in order to demonstrate the basic trends in the radiolarian data and illustrate their relationships to fluctuations in their physical environment. Multiple linear regression is used to explore the relationship between radiolarian composition and the export of carbon from this system.
The most important physical process controlling variability in the radiolarian composition along this transect is attributed to variability in the intensity of the southward-flowing California Current. The seasonality of the California Current is clearly reflected by changes in the composition of the radiolarian trap assemblages; very different species dominate this region in summer as compared to winter. In addition to seasonal trends, evidence in both the offshore and onshore environments suggests significant differences between years. This region appears to have been more strongly influenced by cold, subarctic water during the winter of 1988/1989 than during the previous year.
The relationship between radiolarian species abundances and the flux of organic carbon strongly indicates that a number of different oceanographic processes contribute to enhanced productivity at these sites. This has important implications when making inferences from the geological record about past changes in the intensity of upwelling in this eastern boundary current system.