bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cambrian
Authors: Brasier M. D. , Ingham J. K. , Rushton A. W. A. 
Published: August 2007

Abstract
Aspects of the history of the Cambrian System, and especially its usage in the British Isles, are discussed by Holland (1974). Rushton (1974), Cowie (1974) and Dhonau & Holland (1974) give general accounts of Cambrian stratigraphy in the British Isles, with extensive bibliographies, and the correlation is discussed by Cowie et al. (1972)
The limits of the Cambrian System are still unsettled. The Precambrian/ Cambrian boundary has been the subject of much recent research, concentrated especially on strata of Tommotian and Meishucunian age (Cowie & Brasier 1989). These stages are characterized by faunas of small shelly fossils but biostratigraphical correlation based on them is still rather insecure and a consensus on the basal Cambrian stratotype has yet to be reached (Brasier 19896)
The upper limit of the Cambrian (the base of the Ordovician System) is likewise unsettled. Cowie et al. (1972) took the base of the Ordovician at the base of the Arenig Series, thereby including the Tremadoc Series in the Cambrian. Nowadays a level at the base of the Tremadoc, for long adopted in continental Europe and elsewhere, is more widely accepted in Britain, and is employed here. However, the exact horizon for the base of the Ordovician, and the locality at which it is to be defined, are still under debate.
There are no standard series defined in the Cambrian System. It has long been customary to speak of Lower, Middle and Upper Cambrian, and treat these as series, but they are employed in different senses in different
Ordovician
Authors: Bevins R. E. , Bluck B. J. , Brenchley P. J. , Fortey R. A. , Hughes C. P. , Ingham J. K. , Rushton A. W. A. 
Published: August 2007

Abstract

Since the publication of the Cambrian and Ordovician correlation charts by the Geological Society (Cowie
et al.
1972; Williams
et al.
1972) it has become more general practice to include the Tremadoc Series in the Ordovician, and although the precise level at which the base of the Ordovician is to be drawn is not finally decided, the limits of the system are generally understood. The upper limit has now been precisely defined at the base of
Parakidograptus acuminatus
Biozone, as exposed at Dob's Linn in the central belt of the Southern Uplands in south Scotland, the underlying
Glyptograptus persculptus
Biozone being relegated to the Hirnantian Stage of the Ashgill Series in the Ordovician System (Cocks & Rickards 1988).

Standard international series for the Ordovician are yet to be decided upon but in Britain the series usually employed are those which have been defined and refined over a period of more than a hundred years, based on successions in Wales, the Welsh Borderland and the north of England, namely: Tremadoc Arenig, Llanvirn, Llandeilo, Caradoc and Ashgill. These have ready application in the Anglo-Welsh area and further afield, particularly in continental Europe and Asia, but the demonstration that the faunas of Scotland and northwestern Ireland have much more in common with those of Laurentia (North America, Greenland and Spitsbergen) makes the direct application of many of these chronostratigraphical terms less relevant than the scheme which has developed for the classification of the North American Ordovician. The latter is still to some extent
Silurian
Authors: Bassett M. G. , Bluck B. J. , Cave R. , Holland C. H. , Lawson J. D. 
Published: August 2007

Abstract

The history of establishment of the Silurian System (and hence of the Silurian Period) and its principal divisions has been reviewed by Cocks
et al
. (1971) and Holland (1984, 1989
a
). The System itself, three of the four Series into which it is divided, and the Stages within these three, are all based upon localities in Britain. The names of all the divisions shown in Fig. I have been ratified by the International Union of Geological Sciences. The two major divisions, Lower Silurian and Upper Silurian, remain informal, but they are useful when degree of precision in correlation does not allow reference at the level of Series (Holland 1989
a
). The boundary stratotypes are all described in Holland & Bassett (1989). Graptolite Biozones have proved especially useful for international correlation in the Silurian and the sequence of Biozones used in Britain is shown in Fig. 1. Correlation of the Biozones wth the global Standard Series and Stages is shown approximately, but is not known with exactitude in all cases.

Geodetically the position of the British Isles in the Silurian remained astride the 25°S latitude, a position it had reached in the later Ordovician (Briden
et al
. 1973); movementwas confined to rotation. During this time the south magnetic pole wandered, in terms of present geography, from near to southwest Africa, to the Horn of Africa in early Silurian times, then back along the equator to west Africa/Brazil at the end of the Silurian.

The Llandovery Epoch was chracterized by marine transgressions. Thus in
Permian
Authors: Smith D. B. , Taylor J. C. M. , Arthurton R. S. , Brookfield M. E. , Glennie K. W. 
Published: August 2007

Abstract
Permian strata in the British Isles crop out mainly in northern and central England but are extensive in the subsurface both on land and in several adjoining offshore areas. Their base is defined as in Smith et al. (1974) and their top is within red beds, overlying the Zechstein evaporites.
We emphasize that both the base and the top of the nominally Permian rocks lie in continental strata almost devoid of stratigraphically useful fossils and that, accordingly, these boundaries are only doubtfully correlated with internationally acceptable biostratigraphic standards.
Subdivision of British Permian strata into Lower and Upper series follows the traditional view summarized by Smith et al. (1974). The junction between the series is taken at the incoming of marine strata in northern England and adjoining offshore areas, and at approximately equivalent levels in continuous continental sequences elsewhere; recent limited palynological studies suggest that the early Permian-late Permian transition adopted here and in most of northwest Europe may be mid or late Kazanian or even Tatarian in age which is somewhat younger than the base-Kazanian/Ufimian position taken in more continuous marine sequences.
There has been no comprehensive revision of the stratigraphy and nomenclature of early Permian strata in and around the British Isles since the work of Smith et al. (1974) and Rhys (1974), but these aspects of the early Permian continental deposits of several cuvettes and inland drainage basins in southwest Scotland were reviewed by Brookfield (1978) and the age of continental deposits in the Elgin area was reconsidered
Palaeogene and Neogene
Authors: Murray J. W. 
Published: August 2007

Abstract
Most of the British Isles has been a land area throughout the Tertiary and the basic shape of the coastline had been determined by the late Palaeocene. Only in southeast England are there marine Palaeogene and Neogene successions and these were deposited in embayments marginal to the North Sea and English Channel.
Much of the key information for the interpretation of the Tertiary history of the British Isles lies offshore. Thousands of kilometres of seismic profiles have been run and hundreds of boreholes drilled, mainly in the search for oil. The only part of the Tertiary which has been of economic interest is the Palaeocene of the northern North Sea. Summaries of the offshore data are given in Woodland (1975) and Illing & Hobson (1981).
Thick Tertiary successions are known from the central Graben of the North Sea, the Rockall Trough and the Faeroe Basin (Map Pg 1). The North Sea was the site of great subsidence caused by thermal relaxation following stretching of the continental crust (Sclater & Christie 1980). None of the Tertiary sediments was deposited in very deep water. By contrast, the Rockall Trough and the Faeroe Basin are underlain by oceanic crust and deep water has existed there throughout the Tertiary. The successions are known only from seismic studies (Roberts 1975) but are thought to be mainly fine-grained and with some contourites.
On a regional scale, the Tertiary history of northwest Europe must be considered in relation to the plate tectonic events proceeding in the adjacent ocean.
Part 3: Sulphate and Carbonate Scale Prediction in North Sea Oil and Gas Fields
Authors: Todd A. C. , Yuan M. D. , McCracken I. R. 
Published: August 2007

Abstract
Water-borne scales of sulphate and carbonate are major production problem in North Sea oil fields. Scale formation results from two processes: reduction in mineral solubility in produced formation water due to drops in temperature and pressure during production, and chemical incompatibility between formation water and injected seawater. Temperature and pressure drops are chiefly responsible for carbonate scale precipitation. Chemical incompatibility between the reservoir formation water and the injected sea-water is the most common cause of sulphate scaling. Furthermore, the precipitation of one mineral scale may be aggravated or alleviated by competitive co-precipitation of other mineral(s) and specific ion effects. This chapter examines the susceptibility of North Sea formation waters to carbonate and sulphate scale precipitation.

Seawater contains a few thousand milligrams per litre (c.2800 mg 1
-1
) of sulphate anions (SO
2-
4
), a small amount (c.420 mg 1
-1
) of calcium ions (Ca
2+
) and trace amounts of barium (Ba
2+
) and strontium (Sr
2+
) ions. In many offshore fields in the northern and central North Sea, the original formation water has trace SO
2-
4
but excessive Ba
2+
and Sr
2+
ions (up to 2000 - 3000 mg 1
-1
) as well as Ca
2+
ions (up to tens of thousands mg l
-1
). In normal oil field conditions, these two types of brines are usually chemically stable when they are kept apart. However, as seawater is injected into the reservoir formation during a waterflooding process, it commingles with the formation water in various locations of both reservoir and production systems to deposit sulphate mineral scales of barite (BaS0
4
), celestite (SrS0
4
)
Part 4: Compositional variations of North Sea formation waters
Authors: Warren Edward A. , Smalley Craig P. , Howarth R. J. 
Published: August 2007

Abstract
A total of 236 individual water analyses from over 70 fields in the North Sea and Norwegian Haltenbanken area were provided by field operators or collated from the literature (Table 4.1). All the data from the field operators were supplied as representative analyses of the formation water for that field. Most of the analyses supplied were routine ten ion analyses with accompanying data on sample type, water resistivity and reservoir conditions. Where these accompanying data were not supplied but were available from other sources, they have been added to the original contribution. Previously published formation water analyses have also been included with accompanying data where available.

Minor ions, such as bromide and lithium, trace metals, organic species such as acetate, and isotopic data were seldom reported. Consequently, maps and figures have only been constructed of the major cations, anions, total dissolved solids and R
w
.

All users of the water data compiled here should be aware of possible variations in data quality. There are a number of concerns, most notably the chemical analysis method, sampling artifacts and sample contamination.
The majority of the chemical analyses of formation waters compiled were not performed by the North Sea field operators themselves, but were produced under contract by a number of service companies. Although routine laboratory methods were used to obtain the data reported here, different methods have been used between laboratories and over time due to improved instrumentation and analytical methods over the last 25 years of oil and gas production from the
The eruption of Soufrière Hills Volcano, Montserrat (1995-1999): overview of scientific results
Authors: Sparks R. S. J. , Young S. R. 
Published: August 2007

Abstract
The eruption of Soufrière Hills Volcano, Montserrat (1995-1999) has displayed a wide range of volcanic phenomena: growth of an andesitic lava dome, generation of pyroclastic flows by lava dome collapse and by fountain collapse in explosive eruptions, Vulcanian and sub-Plinian explosivity with accompanying tephra fall, entrance of pyroclastic flows into the sea, sector collapse with formation of a debris avalanche and a high-velocity pyroclastic density current, and generation of lahars. New phenomena include: cyclic patterns of ground deformation linked with shallow seismicity and eruptive activity; pyroclastic flows formed by rapid sedimentation from pyroclastic surges; and an unprecedented slow escalation of eruption intensity. Magma pulsations with timescales of hours to years have been recognized. Transitions from extrusive to explosive activity were triggered by major dome collapses. Relationships between magma ascent dynamics and geophysical signals have been elucidated. Ascending water-rich andesitic magma becomes Theologically stiffened by degassing and groundmass crystallization. Large magma overpressures are consequently developed in the upper conduit, causing shallow seismicity, radial patterns of ground deformation, and cyclic pulsations of eruptive activity. Lava dome growth involved heterogeneous deformation with formation of spines and lobes along shear zones. Collapse of the pressurized dome resulted in substantial pyroclastic surges forming above pyroclastic flows. Influx of hydrous mafic magma remobilized hot crystalline igneous rocks at depths of 5 to 6 km to form crystal-rich andesitic magma and triggered the eruption.
The Montserrat Volcano Observatory: its evolution, organization, role and activities
Authors: Aspinall W. P. , Loughlin S. C. , Michael F. V. , Miller A. D. , Norton G. E. , Rowley K. C. , Sparks R. S. J. , Young S. R. 
Published: August 2007

Abstract
The Montserrat Volcano Observatory (MVO) is a statutory body of the Government of Montserrat and is the organization responsible for volcano monitoring operations on the island. It was formed shortly after the first phreatic explosions from Soufrière Hills Volcano occurred on 18 July 1995, and evolved from a hastily created, interim entity to a fully established volcano monitoring operation. Participating scientific teams have been drawn mainly from the Seismic Research Unit of the University of the West Indies, the US Geological Survey, the British Geological Survey and universities from various countries including the USA, UK, France and Puerto Rico. Despite its hurried inception, the MVO has been able to provide timely, high quality hazard advice to the civil authorities and has maintained an exceptional documentary record of all scientific aspects of the eruption. Its public education and information efforts have been extensive and there have been unusually high levels of interaction between scientists and the civil authorities, and between scientists and the public, both within Montserrat and outside in the wider world. The experience of setting up and running the MVO, under difficult and stressful conditions, has exemplified the advantages of teamwork and flexibility within monitoring operations and the benefits of openness and clarity in public interactions. Novel techniques have been applied to the appraisal of hazards and advances in scientific understanding have proved invaluable for risk assessment and management.
Dynamics of magma ascent and lava extrusion at Soufrière Hills Volcano, Montserrat
Authors: Melnik O. , Sparks R. S. J. 
Published: August 2007

Abstract

Growth of the andesitic lava dome during eruption of Soufrière Hills Volcano, Montserrat involved general increases in discharge rate and dome height with superposed fluctuations on timescales from hours to months. We have modelled magma conduit flow incorporating viscosity variations caused by degassing and crystallization. Gas loss is modelled by permeable flow, with variations of permeability constrained by measurements. Crystallization kinetics is modelled by an Avrami law. Observations and petrological studies constrain conduit diameter (
c
. 30 m), magma chamber crystal content (
c
. 60-65%), melt water content (
c
. 5%), magma temperature (
c
. 850°C) and chamber depth (
c
. 5 km). Gas loss and rheological stiffening cause a maximum in magma overpressure (magma pressure minus lithostatic pressure) at depths of a few hundred metres below the dome. This maximum can explain ground deformation patterns, shallow seismicity, and short-lived Vulcanian explosions. Crystallization kinetics causes a strong feedback mechanism and multiple steady solutions for discharge rate. Small changes in chamber pressure, magma viscosity and conduit diameter strongly amplify discharge rate. Multiple solutions allow cyclic variation of discharge rate. Escalation of activity is attributed principally to influx of hot mafic magma into the chamber, resulting in chamber pressure increasing with time. Dome growth can be intrinsically unpredictable due to non-linear effects.
Mechanisms of lava dome instability and generation of rockfalls and pyroclastic flows at Soufrière Hills Volcano, Montserrat
Authors: Calder E. S. , Luckett R. , Sparks R. S. J. , Voight B. 
Published: August 2007

Abstract

Between 3 January 1996 and 1 December 1998 at Soufrière Hills Volcano, Montserrat, there were 27150 seismic signals attributable to rockfalls and pyroclastic flows. Large (1-4 x 10
6
m
3
) and major (>4 x 10
6
m
3
) dome collapses began to occur after the extrusion rate reached 2 m
3
s
-1
and the lava dome exceeded 30 x 10
6
m
3
in volume. Large to major collapses occurred on 26 occasions and were usually associated with periods of elevated extrusion rate (6 13 m
3
s
-1
), intense hybrid earthquake swarms and/or inflation-deflation cycles of crater-rim ground deformation. During these cycles, gas-rich pulses of magma, 140 000 320 000 m
3
in volume, were intruded into the dome and, soon thereafter, dome collapses from the headwalls of shear lobes were generated. Large dome collapses also occurred after 10 March 1998, when magma extrusion ceased, but these had no seismic precursors. These events represent structural failures from over steepened canyon-like walls and were followed by intense degassing, suggesting that gas pressure build-up within the relict dome may have played some role. Rockfall counts and durations established from seismic data show variations that correlate with extrusion rate. Using pyroclastic flow runout and rockfall duration data as proxies for event magnitude, power law relationships between frequency (total number of events) and magnitude have been found. Seismic signals associated with rockfalls and pyroclastic flows commonly comprise both high-frequency and long-period components. Intense degassing from the dome is interpreted as the source for the long-period component. These results indicate that rockfalls and pyroclastic flows generated by dome collapse at Montserrat are not simply the result of passive dome failure, but are intimately related to discharge of pressurized gas and pulses of magma extrusion. Pyroclastic flows were usually sourced from lobe headwalls, where lava was hot and gas-rich and where fragmentation of the micro vesicular andesite lava occurred more readily.
Pyroclastic flows and surges generated by the 25 June 1997 dome collapse, Soufrière Hills Volcano, Montserrat
Authors: Loughlin S. C. , Calder E. S. , Clarke A. , Cole P. D. , Luckett R. , Mangan M. T. , Pyle D. M. , Sparks R. S. J. , Voight B. , Watts R. B. 
Published: August 2007

Abstract

On 25 June 1997, an unsteady, retrogressive, partial collapse of the lava dome at Soufrière Hills Volcano lasted 25 minutes and generated a major pulsatory block-and-ash flow, associated pyroclastic surges and a surge-derived pyroclastic flow that inundated an area of 4 km
2
on the north and NE flanks of the volcano. Three main pulses are estimated to have involved 0.78, 2.36 and 2.36 x 10
6
m
3
of debris and the average velocities of the fronts of the related block-and-ash flow pulses were calculated to be 15 ms
-1
, 16.1 ms
-1
and 21.9 ms
-1
respectively.

Deposits of block-and-ash flow pulses 1 and 2 partially filled the main drainage channel so that material of the third pulse spilled out of the channel at several places, inundating villages on the eastern coastal plain. Bends and constrictions in the main drainage channel, together with depositional filling of the channel, assisted detachment of pyroclastic surges from the pulsatory block-and-ash flow. The most extensive pyroclastic surge detached at an early stage from the third block-and-ash flow pulse, swept down the north flank of the volcano and then climbed 70 m in elevation before dissipating. Rapid sedimentation from this surge generated a high-concentration granular flow (surge-derived pyroclastic flow) that drained westwards into a valley not anticipated to be at high risk.
Observations support the hypothesis that the interior of the Soufrière Hills Volcano lava dome was pressurized and that pyroclastic surge development became more substantial as deeper, more highly pressurized parts of the dome were incorporated into the pyroclastic flow. Surge development was at times so violent that expanded clouds detached from the block-and-ash flow within a few tens of metres of the lava dome.
Eyewitness accounts of the 25 June 1997 pyroclastic flows and surges at Soufrière Hills Volcano, Montserrat, and implications for disaster mitigation
Authors: Loughlin S. C. , Baxter P. J. , Aspinall W. P. , Darroux B. , Harford C. L. , Miller A. D. 
Published: August 2007

Abstract
Eyewitness and survivor accounts allow reconstruction of the sequence of events on 25 June 1997, when a sustained partial collapse of the lava dome occurred leading to the death of 19 people. An unsteady pyroclastic flow was generated with three distinct pulses. The third flow pulse caused most of the damage to infrastructure and most, if not all, of the casualties. Pyroclastic surges detached along most of the path of the third flow pulse, and one travelled 70 m up an adjacent hillside.
Observations were made that will be important for the development of mitigation measures at future events involving high-temperature flows and surges. Temperatures remained high (300-400°C) at the periphery of the most voluminous and extensive surge, even though dynamic pressure and velocity were low, causing the death of seven victims. Some people survived at the margins of the surge zone but suffered serious burns when they were forced to walk across the hot surge deposits to safety. Deflagration of buildings and vegetation was immediate within the pyroclastic surge and intense fires burned long after the volcanic activity had ceased. Fires could be a serious secondary hazard in an urban area. Search-and-rescue efforts were hampered in the immediate aftermath of the pyroclastic flows and surges by smoke and ash in the atmosphere. The hot, locally gas-rich surge deposits posed a major hazard to search-and-rescue workers and volcanologists for days afterwards.
Despite the efforts of officials, scientists and concerned members of the public, about 80 people were in Zones A and B of the Exclusion Zone on 25 June 1997. Our findings suggest that many had become accustomed to the pyroclastic flows and had become overconfident in their own ability to judge the threat by observing repeated flows that had gradually increased runout but remained restricted to valleys. Many people had contingency plans and believed that there would be observable or audible warning signs from the volcano if the activity were to escalate significantly. However, there were no such discernible warnings and individual contingency plans proved inadequate. Public education should concentrate on correcting such public misapprehension of hazardous phenomena and attendant risks in future volcanic crises.