bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stratigraphic and palaeogeographic distribution of Palaeozoic oolitic ironstones
Authors: Van Houten F. B. , Hou Hong-Fei 
Published: April 2008

Abstract
The record of Palaeozoic oolitic ironstones reflects second-order Phanerozoic sea-level changes. Middle Cambrian- earliest Ordovician high stand: scattered ironstones developed on low-latitude Laurentia and locally on high southern-latitude NW Africa and Nova Scotia. Early-early Late Ordovician high stand: major and scattered minor ironstones were widespread on high southern-latitude N Africa and Peri-Gondwanan blocks. Minor ones on C Laurentia, NE and SW Baltica, SW Kazakhstan, and NW and SW Siberia, NW Malaysia, and C Australia accumulated in middle and low latitudes, as did all later Palaeozoic ironstones. Latest Ordovician-earliest Silurian low stand: during southern-latitude glaciation minor ironstones were limited to WC Algeria and low-latitude C and SE Laurentia. Early-early Late Silurian high stand: minor ironstones accumulated on NC, WC, and SE South America, N Africa, and Peri-Gondwanan blocks, while major ones developed on NW Africa and CE Laurentia. Latest Silurian-Early Devonian low stand: major ironstones developed on WC Algeria; minor ones on CE Laurentia, several Peri-Gondwanan blocks, N and W Africa, NC South America, and South China. Middle-early Late Devonian high stand: major ironstones accumulated on N Africa, SE Baltica, NW Iberia, and South China; minor ones on SW and CE Laurentia, and NW and SE Middle Europe. Latest Devonian-earliest Carboniferous low stand: well-developed latest Devonian ironstones were limited to N Africa and NW Middle Europe, minor ones to SE Middle Europe and CE Laurentia; minor earliest Carboniferous ones to NW Middle Europe and NC Africa.
The relationship of Ordovician graptolite provincialism to palaeogeography
Authors: Finney Stanley C. , Chen Xu 
Published: April 2008

Abstract

Graptolite biogeography is examined for the late Arenig-Llanvirn when provincialism was at its greatest and the Llandeilo-Caradoc when graptolites were cosmopolitan. This examination incorporates new data from China and recently revised palaeogeographic base maps. Water-mass specificity is considered to be the primary factor affecting graptolite biogeography. On the recently revised base maps, the distribution of Pacific and Atlantic provinces in the late Arenig-Llanvirn is in general consistent with the model of water-mass specificity and the hypothesis that climate cooling associated with the onset of continental glaciation lead to the development of provincialism. However, a small clockwise rotation of South America and a slight northward shift in the position of North America is recommended. The climatic-cooling hypothesis includes the proposal that continued cooling confined graptolites to the tropics where the uniform environment precluded provincialism. The distribution of the cosmopolitan fauna of the
Nemagraptus gracilis
Zone in relationship to the Llandeilo-Caradoc palaeogeography is consistent with this hypothesis, except for the positions of the European platform, Britain, Armorica, and the Carpathians in the mid to high southern latitudes. Either the latitudinal positions of these areas must be shifted substantially to the north, or the climatic-cooling hypothesis mnst be in error.
Cambro-Devonian biogeography of nautiloid cephalopods
Authors: Crick Rex E. 
Published: April 2008

Abstract
The biogeography of Cambro-Devonian nautiloid cephalopods is documented from their origin during Late Cambrian through to the end of the Devonian. The biogeography developed as the consequence of two related sets of events with different magnitudes. Events controlling the biogeography of first order magnitude were geotectonic, either Gondwana glaciation due to plate movement or contraction in size of oceanic ridges related to decreased rates of sea floor spreading, manifested as first and second order eustatic fall in sea level. These first order events separate nautiloid biogeography into four episodes: (1) Late Cambrian; (2) Ordovician; (3) Silurian through Early Devonian; and (4) Middle through Late Devonian. Each began with an expansion in terms of generic diversity and ended with a crisis of some proportion. Only the end of the Late Cambrian episode cannot be explained by geotectonic events.
Events of the second order are both biologic and geotectonic and involve the interaction between the dispersal characteristics of nautiloid cephalopods and plate movements. Due to lack of a planktonic larva and depth restrictions as a function of shell design, the ability of nautiloids to disperse and colonize shallow shelf seas separated by expanses of ocean or depths exceeding shell design limits was minimal. When the width of oceans or depths decreased through some form of geotectonics, nautiloids rapidly radiated and colonized regions as they became available. Thus second order biogeographic episodes tend to evolve from a collection of disjunct patterns with high faunal similarity among faunas of particular landmasses, but with little similarity among separate landmasses, to rapid development of high similarities both among and within faunas of converging landmasses once the physical barrier of distance and water depth is eliminated.
The biogeographic affinities of East Asian corals
Authors: Liao Wei-Hua 
Published: April 2008

Abstract
In East Asia the oldest tabulate and rugose corals appeared in the Early and Middle Ordovician. All rugose corals and most tabulate corals appear to have become extinct at the end of the Permian.
The Ordovician corals of North China were most closely related to the Americo-Siberian region, but those of South China occupied an independent province. The Silurian corals of Junggar, Hinggan, Mongolia, Altai and Tuva are genera characteristic of the Uralian-Cordilleran region. The South China fauna had a close affinity to that of the East Australia in the Early Silurian, but was more akin to that of the Urals and Central Asia in the Middle and Late Silurian. During the Early and Middle Devonian, there were 5 biogeographic provinces in East Asia, all belonging to the Old World Realm: (1) Arctic province; (2) Junggar-Hinggan province; (3) Uralo-Tian Shan province; (4) Palaeotethyan province and (5) South Chin province.

In East Asia, two distinctive zoogeographic provinces are fairly clearly defined: a southern province, with occurrence of
Kueichouphyllum
and a northern province with occurrences of
Gangamophyllum
during the Early Carboniferous. In addition, during the Early Permian, a Uralo-Arctic province was dominated by Durhaminidae and a Tethyan province by Waagenophyllidae.
The Silurian and Early Devonian biogeography of ostracodes in North America
Authors: Berdan Jean M. 
Published: April 2008

AbstractSilurian and Early Devonian ostracode associations in North America represent at least three ecotypes, a leperditicopid association, a large beyrichiacean association, a mixed association, and possibly a fourth, spinose podocopid association, or Thuringian ecotype. Comparison of the large beyrichiacean association and mixed association ecotypes indicates the presence of three informal ostracode provinces, the Appohimchi, Baltic-British and Cordilleran, which remained relatively constant in geographical position throughout the Silurian and Early Devonian. Plotting the provinces on palaeogeographic maps suggests that temperature was not an important factor in delimiting the provinces, and land barriers, or possibly deep-water troughs as barriers, were the cause of provincial development. Benthic ostracodes differed from other benthic invertebrates such as brachiopods and corals in developing provincialism in the late Llandovery and having it start to decline in the Pragian through the Emsian.
Constraints on Siluran and Early Devonian phytogeographic analysis based on megafossils
Authors: Edwards Dianne 
Published: April 2008

Abstract

The detection of phytogeographic patterns in Silurian and Early Devonian land vegetation is hampered by the dearth of occurrences of megafossils, the absence of consistently precise correlation, unreliability of identification, and the lack of sufficient detailed sampling and information on sediments to permit evaluation of taphonomic influences on composition of assemblages. Interpretation is further complicated by the exceptional evolutionary position of the plants themselves and the lack of extant representatives. There is little information on whole plants, their life histories, their ecological and climatic tolerances. The composition of Ludlow, Pridoli and Lochkovian/Gedinnian assemblages is analysed. Those from Kazakhstan and Siberia are particularly enigmatic. The assemblages are plotted on the appropriate continental reconstructions. Most are clustered on the southeast margin of Laurussia and very few occur at high latitudes. In Ludlow time,
Baragwanathia
dominated assemblages in Australia in contrast with the rhyniophytoid assemblages of Laurussia. New information from Kazakhstan and northwest China adds to the data base in the Pridoli.

Differences in Gedinnian assemblages from South Wales, the Welsh Borderland and Scotland, where sediments have been intensively studied and correlation is based on fish faunas and, more usefully, on palynomorphs, are related to taphonomy, to local vegetation distribution pattern, and to evolutionary changes. World-wide analysis of occurrences shows four distinct assemblages, based on Laurussia, Kazakhstan, Australia and Siberia, the latter being a rare example of high latitude vegetation.
Devonian vertebrate distribution patterns and cladistic analysis of palaegeographic hypotheses
Authors: Young Gavin C. 
Published: April 2008

Abstract
Early Devonian vertebrate faunal provinces are clearly defined for four regions: Euramerica, Siberia, China, and East Gondwana. The presence of osteostracans in southwest Siberia (Tuva, Minusa Basins) suggests either proximity of the Siberian block to Euramerica, or palaeogeographic separation of the Tuva region. The Knoydart fauna of Nova Scotia demonstrates that the Avalon Terrane was connected to Euramerica by Gedinnian time. Widespread antarctilamnid sharks in Gondwana suggest a distinctive Gondwana vertebrate fauna, isolated by marine barriers from Euramerica in the Early - Middle Devonian. Late Devonian patterns indicate faunal communication between Gondwana and Euramerica by Frasnian time, and between China and East Gondwana in the late Famennian. The Late Devonian base maps require anomalously wide latitudinal distributions for some taxa. Displacement of Turkey along the northern margin of Gondwana provides an intermediate occurrence of phyllolepid placoderms between disjunct distributions in Euramerica and East Gondwana, but the fossil data do not necessarily corroborate geological evidence for displacement. Biogeographic data generally must be interpreted in the context of palaeogeographic hypotheses, and lack of integration with geological and geophysical data sets has been a major problem. Hierarchical analysis using cladistic techniques has the potential for integrating biological, geological, and geophysical data, as illustrated in a cladistic analysis of the Williams and Hatcher model of Appalachian terranes. As an adjunct to map representation, an area cladogram enables a historical sequence of palaeogeographic events to be represented on a single diagram, together with crucial supporting evidence; it presents an analysis rather than synthesis of empirical data, and the hypothesis is more exposed to falsification.
Late Palaeozoic bryozoan biogeography
Authors: Ross J. P. R. , Ross C. A. 
Published: April 2008

Abstract
Late Palaeozoic (Carboniferous and Permian) distributions and times of dispersal of bryozoans, fusulinids, and other marine shelf invertebrates were greatly influenced by the effects of land masses converging to form a supercontinent. This convergence modified oceanographic circulation patterns as well as environmental, climatic, and temperature patterns. Sea level fluctuations of 75 to 100 metres having about two million years duration also strongly affected faunal dispersal patterns. At the end of the Early Carboniferous (late Visean through early Bashkirian), the assemblage of Lesser Pangaea disrupted the tropical, subtropical and warm temperate marine shelf faunas which included cryptostomes, trepostomes, and cystoporates. In the middle of the Early Permian (Leonardian), the assemblage of Greater Pangaea further disrupted the marine shelf faunas giving rise to biogeographic provinces and finally realms. In the assembling of Pangaea, the northward transport of plates and cratons caused the northern marine shelf of Pangaea to be moved into cooler and cooler waters. Tectonic movements caused cool ocean currents to be redirected toward the equator along the western marine shelves of Pangaea. Faunal diversity greatly increased apparently as a result of the flow of consistently warm equatorial currents along the eastern marine shelves of Pangaea.
Phytogeographic patterns and continental configurations during the Permian Period
Authors: Ziegler A. M. 
Published: April 2008

Abstract
The climatic influences on vegetation in the present world can serve as an excellent model for the Permian, there being approximately the same level of floral differentiation and the same relatively cold polar regions. Accordingly, a system of present day climatically defined biomes, developed by Walter, is adapted herein for palaeophytogeographic purposes. There are ten biomes altogether which range from the tropical 'everwet' (biome 1) to the polar 'glacial' (biome 10).

Biome 1 is represented by the tropical rainforests of the Cathaysian province
sensu stricto
which was populated by the arborescent lycopods and sphenophytes, and the Gigantopterids which are interpreted as lianas (vines). This is flanked by the lower diversity 'summerwet' biome 2, the Atlantic Province, a zone which today is characterized by savanna vegetation, and in the Permian was represented by the pteridosperm
Callipteris
and the primitive conifers. Biome 3 was effectively 'abiotic' and is expressed geologically by evaporite belts.

The 'winterwet' or Mediterranean climate of today (biome 4) was not well developed in the Permian, or perhaps just not well preserved, but I attribute some low diversity floras of Kazakhstan to this biome. Biome 5, the 'warm temperate' biome is well developed in both hemispheres, and, like biome 1, is characterized by high diversity floras and abundant swamp deposits. Not surprisingly, the biome 5 floras have been mistaken for biome 1 with which they are transitional in the modern world and with which they share similar climatic conditions. In the Permian Angaran Realm, the Pechora Province represents this biome, while the Austroafroamerican Province is the Gondwanan equivalent. Often, biome 5 floras have been simply termed 'mixed'. Proceeding poleward across the 'hard frost line', the cool temperate floras of biome 6 were populated by diverse herbaceous sphenophytes and deciduous trees (the cordaitids of Angara and the similarly diverse glossopterids of Gondwana). Areas in the temperate zone that were remote from moisture sources are assigned to biome 7 and are only known in the southern hemisphere by some aeolian deposits in Argentina. The 'cold temperate' biome 8 is a low diversity equivalent of biome 6, and has been given the name
Gangamopteris
Flora in the southern hemisphere. The 'tundra' environment, biome 9, and the truly glacial deposits, biome 10, are known only from the southern hemisphere.
Palaeogeographic evolution of southwestern Europe during Early Palaeozoic times
Authors: Robardet M. , Paris F. , Racheboeuf P. R. 
Published: April 2008

Abstract
In the Late Ordovician, both SW Europe and Africa were situated in high latitudes. Sedimentary fades and biogeography suggest that these regions were separated by the Rheic (Mid-European) Ocean from Baltica, with the suture lying between the Armorican Massif and the Ardennes. During the Silurian and the Devonian, palaeobiogeographic affinities persisted between S Europe and N Africa. It is concluded that S Europe consisted of several discrete blocks or microplates prior to the Hercynian Orogeny.
Ordovician sedimentary facies and faunas of southwest Europe: palaeogeographic and tectonic implications
Authors: Young T. P. 
Published: April 2008

Abstract
The term st European Platform is introduced for an Ordovician shelf now within the western Variscides. The geometry of the sedimentary facies belts and their faunal variation suggest that it formed a promontory on the Gondwanan margin. The palaeogeography of the platform is discussed with particular reference to the Centro-Iberian/Armorican area, especially central Portugal.
The sedimentary history of the Centro-Iberian/Armorican area was controlled by basement structures. Rapid local subsidence during Early Ordovician extension was followed by later differential subsidence along these early structures. The thin sequences indicate low overall rates of subsidence. The dominantly clastic shallow marine sediments show strong storm influence. Individual sediment packets occur over wide areas indicating little syndepositional relief. The linear nature of facies belts allows reconstruction of the relative orientation of some blocks within the Variscides, and indicates strike-slip faulting during early Variscan events, with subsequent (Carboniferous) rotation of most of Iberia.
Faunas from SW Europe from a homogeneous group related to those of the classic 'Mediterranean Province' areas of Bohemia and Morocco, and more distantly to those of the Avalonian terrane. Faunal migration into the West European Platform from Avalonia accompanied progressive northward drift of the platform, occuring particularly during periods of eustatic sea-level rise in the early Llanvirn, the early Caradoc and the early Ashgill
Stratigraphy of the oil and gas reservoirs: UK Continental Shelf
Authors: Brown Stewart 
Published: April 2008

The petroliferous sedimentary basins of the UK Continental Shelf are remarkable for the diversity of their reservoir strata. Reservoir rocks in fields currently in production range in age from Devonian to earliest Eocene, but significant hydrocarbon discoveries have also been made in rocks as as young as the mid-Eocene. The reservoirs are predominantly siliciclastic rocks, with facies ranging from continental fluvial and aeolian, to marine gravity flow deposits from sub-wave base environments.
In this paper stratigraphic context of the producing horizons in the UK Continental Shelf (UKCS), principally the North Sea, is reviewed, and the sedimentation of the reservoir strata placed in an outline geological history. The main producing horizons are described in summary. Matters of stratigraphic terminology and correlation both between fields and between basins are discussed.
A lithostratigraphy for the UK southern North Sea was established by Rhys (1974), and for the central and northern North Sea by Deegan & Scull (1977). Although these schemes have proved to be fairly robust, in the last 13 years the acquisition of new data plus a proliferation of new terms not fully documented in the public domain, argue strongly for a comprehensive revision and rationalization which is beyond the scope of this paper. Attempts in the public domain to standardize nomenclature across international boundaries in the North Sea, pursued by Deegan & Scull (1977) for the UK and Norwegian sectors, have lapsed for the most part in subsequent years.
Economic basement in the UK North Sea can be regarded at present
The Beryl Field, Block 9/13, UK North Sea
Authors: Knutson C. A. , Munro I. C. 
Published: April 2008

Abstract
The Beryl Field, the sixth largest oil field in the UK sector of the North Sea, is located within Block 9/13 in the west-central part of the Viking Graben. The block was awarded in 1971 to a Mobil operated partnership and the 9/13-1 discovery well was drilled in 1972. The Beryl A platform was emplaced in 1975 and the Beryl B platform in 1983. To date, ninety-five wells have been drilled in the field, and drilling activity is anticipated into the mid-1990s.
Commercial hydrocarbons occur in sandstone reservoirs ranging in age from Upper Triassic to Upper Jurassic. Structurally, the field consists of a NNE orientated horst in the Beryl A area and westward tilted fault blocks in the Beryl B area. The area is highly faulted and complicated by two major and four minor unconformities. The seal is provided by Upper Jurassic shales and Upper Cretaceous marls.
There are three prospective sedimentary sections in the Beryl Field ranked in importance as follows: the Middle Jurassic coastal deltaic sediments, the Upper Triassic to Lower Jurassic continental and marine sediments, and the Upper Jurassic turbidites. The total ultimate recovery of the field is about 800 MMBBL oil and 1.6 TCF gas. As of December 1989, the field has produced nearly 430 MMBBL oil (primarily from the Middle Jurassic Beryl Formation), or about 50% of the ultimate recovery. Gas sales are scheduled to begin in the early 1990s. Oil and gas production is forecast until licence expiration in 2018.
The Beryl Fields is located 215 miles northeast of Aberdeen, about 7 miles from the United Kingdom-Norwegian boundary. The field lies within Block 9/13 and covers and area of approximately 12 000 acres in water depths ranging from 350-400 ft. Block 9/13 contains several hydrocarbon-bearing structures, of which the Beryl Fields is the largest (Fig. 1). The field is subdivided into two producing areas: the Beryl Alpha area which includes the initial discovery well, and the Beryl Bravo area located to the north. The estimated of oil originally in place is 1400 MMBBL for Beryl A and 700 MMBBL for Beryl B. The fiel has combined gas in place of 2.8 TCF, consisting primarily of solution gas. Hydrocarbon accumulations occur in six reservoir horizons ranging in age from Upper Triassic to Upper Jurassic. The Middle Jurassic (Bathonian to Callovian) age Beryl Formation is the main reservoir unit and contains 78% of the total ultimate recovery.
The field was named after Beryl Solomon, the wife of Charles Solomon, who was president of Mobil Europe in 1972 when the field was discovered. The satellite fields in Block 9/13 (Nevis, Ness and Linnhe) are named after Scottish lochs.
The South Brae Field, Block 16/7a, UK North Sea
Authors: Roberts Martin J. 
Published: April 2008

Abstract
South Brae Oilfield lies at the western margin of the South Viking Graben, 161 miles northeast of Aberdeen. Oil production began in July 1983 from a single platform located in 368 ft of water. The field originally contained 312 MMBBL of recoverable reserves, and in May 1990, cumulative exports of oil and NGL reached 219 MMBBL. The reservoir lies at depths in excess of 11800 ft TVSS, has a maximum gross hydrocarbon column of 1670 ft, and covers an area of approximately 6000 acres.
The reservoir is the Upper Jurassic Brae Formation which is downfaulted against tight sealing rocks of probable Devonian age at the western margin of the field. The other field margins are constrained by a combination of structural dip and stratigraphic pinchout.
The reservoir is capped by the Kimmeridge Clay Formation, which is also the source of the oil.