bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geoscience data value, cost and management in the oil industry
Authors: Miller Richard G. , Gardner John S. 
Published: April 2008

Abstract
BP Exploration, through its Frontier and International division (XFI), is the first oil major to openly release some of its international exploration data, information and internal reports to competitors for cash. The data and information relate to geographical areas in which the company foresees no strategic interest.
There are various ways in which such a programme could be run. In our case, all exploration information and data have an identified owner, usually the asset manager responsible for exploration in the relevant part of the world. A dedicated XFI data broking team identifies and prices material for possible exchange or licence sale. The asset manager who owns the material certifies whether it may be released without damage to the company’s competitive position. Legal staff check the ownership of the material, and ensure that there are no confidentiality constraints. Commercial brokers then either offer released material to the open market or create new products from it for licencing. The material is licenced for use rather than sold, so that the recipient cannot re-sell it. All income accrues centrally to XFI rather than to the asset manager; altruism by the owners of the data is central to our data brokerage philosophy.
Such marketing follows naturally from treating data and information as a true asset, whose value can be established in the market-place. When such marketing becomes the industry standard, then XFI can also enter the market-place as a buyer. Those who can buy existing exploration data and information will save the great cost of generating their own. This is part of a sea-change in the industry, in which the players are moving towards a lower cost base through shared activity as opposed to duplicated activity.
Groundwater level archive for England and Wales
Authors: Doorgakant P. 
Published: April 2008

Abstract
The monitoring of groundwater levels is important for the management of groundwater resources. Within the United Kingdom a selection of observation boreholes are monitored for periodic assessment of the groundwater resources. The measurement of groundwater levels is undertaken principally by the water companies, the National Rivers Authority (NRA) for England and Wales, the River Purification Boards (RPB) for Scotland and the Department of the Environment (DoE) for Northern Ireland. Weekly and monthly data are supplied to the British Geological Survey (BGS) and these data are entered into an ORACLE database where they are assimulated with historical records. Additionally, paper copies are archived. Data usage is facilitated by a number of computer retrievals including well hydrographs in graphic form. Access to the groundwater level information is made available to the public at a small operational cost. A number of publications are produced giving a review on groundwater, including an assessment of recharge to major aquifers and also a number of hydrographs are illustrated from the key boreholes. The database has proved to be an invaluable tool in predicting environmental change, such as droughts and rising groundwater levels.
CD-ROM and its application to the petroleum industry
Authors: Allen Stephen G. 
Published: April 2008

Abstract
Over the last few years CD-ROM has emerged in many industries and professions as an essential means of distributing and accessing information. The petroleum industry, however, has been slow to realize the potential of this medium with, until recently, only a few isolated applications available. A detailed description of the CD-ROM medium and its manufacture is provided and its relevance to the oil industry discussed. Some examples of early and current applications are presented and discussed.
Magnetostratigraphic correlations of the Jurassic carbonates from the Paris Basin: implications for petroleum exploration
Authors: Belkaaloul Kifaya N. , Aissaoui Djafar M. , Rebelle Michel , Sambet Gerard 
Published: April 2008

Abstract
Shallow water carbonates from the Middle Jurassic of the Paris Basin include oil reservoirs, mainly oolitic and bioclastic limestones. Biostratigraphic markers within these deposits are generally used for regional correlations. Unfortunately, these markers are not available in all cored sections. A pilot study has shown that palaeomagnetism could be used to better constrain the chronostratigraphic framework of the Jurassic shallow water carbonates. Because the magnetization of sediments is independent of facies and location, palaeomagnetic dating may allow higher resolution.
Further magnetostratigraphic results are reported for three additional well dated core sections (53, 18.50 and 36.35 m in length) correlated throughout the Paris Basin. Specimens were subjected to alternating field and stepwise thermal demagnetization. The demagnetization paths show either one, two or three components. Based on the primary magnetization component, normal and reverse polarity intervals occur in the three sections. Rock magnetic experiments performed on representative specimens from both sections indicate that the bulk of the natural remanent magnetization is carried mainly by low coercivity minerals such as magnetite/maghemite and high coercivity minerals exclusively in altered layers of the cores. Single domain maghemite, probably biogenic in origin, has been observed by transmission electron microscopy. Larger detrital irregular titanomagnetite and secondary, framboidal magnetite spheres have been characterized with a scanning electron microprobe. The occurrence of the secondary magnetic spheres is probably related to the transformation of framboidal pyrite into magnetite during hydrocarbon migration. This has presumably resulted in the overprint of a secondary magnetization.
The polarity sequences have been correlated with the magnetostratigraphic record defined for the Bathonian and Callovian. The correlation is fairly good for the Bathonian, but ambiguous for the Callovian. However, we used a characteristic reverse polarity interval occurring in all our cores, including that studied previously, to correlate strata throughout the Paris Basin. The positive correlation within these strata provides a strong potential for the analysis of reservoir geometry and quantitative modelling of the Middle Jurassic shallow water carbonates.
Palaeomagnetic study of Cenozoic sediments in North Sea boreholes: an example of a magnetostratigraphic conundrum in a hydrocarbonproducing area
Authors: Thompson R. , Cameron T. D. J. 
Published: April 2008

Abstract
Palaeomagnetic measurements from a southern North Sea borehole that penetrated 13 m of Holocene, 189 m of Plio-Pleistocene and 4 m of Oligocene sediments have yielded six polarity changes. One polarity boundary coincides with a regional mid-Tertiary unconformity and a second occurs at the base of the Holocene section. The other four boundaries are interpreted as the Kaena-Gauss and the Gauss-Matuyama polarity transitions, and the base and top of the Olduvai subchron. The borehole results provide a chronological framework for interpreting nearby seismic sections and for assessing the sedimentation rates as a major Plio-Pleistocene delta complex approached and then overwhelmed the borehold site. Rock magnetic and X-ray diffraction work show that the iron sulphide greigite is an important magnetic mineral in the prodelta and delta front marine clays and lagoonal delta top clays, whereas magnetite is the dominant magnetic mineral in the fluvio-deltaic sands and in the Holocene and Oligocene marine deposits. Thermal demagnetization studies demonstrate that the greigite carries a stable natural remanent magnetization. It may have formed through sulphide diagenesis induced by hydrocarbon seepage or in a reducing sedimentary environment. Greigite is surprisingly difficult to detect through the standard palaeomagnetic method of alternating field demagnetization and may be of much greater palaeomagnetic importance in hydrocarbon-producing areas than previously supposed.
Viscous remanent magnetization: a tool for orientation of drill cores
Authors: Rolph T. C. , Shaw J. , Harper T. R. , Hagan J. T. 
Published: April 2008

Abstract
To interpret the directional physical properties of reservoirs it is necessary to obtain orientated specimens of well material. The standard technique in the petroleum industry has been the use of ‘down the hole’ tools, which leave a physical scribe on the core material during the drilling procedure. This method is expensive and is subject to a number of problems which can limit the accuracy of the results. A new orientation technique is presented in which a present day component of magnetization is isolated during the progressive thermal demagnetization of core material. This component is essentially a magnetic compass bearing for the core which can be used to rotate the core reference frame into the geographical system. Unlike the standard palaeomagnetic method it can be used both on undated core and core taken from complex tectonic areas.
Palaeomagnetic analysis of fold closure growth and volumetrics
Authors: Stewart S. A. , Jackson K. C. 
Published: April 2008

Abstract
Fold closures (four-way dip closures) occur in several tectonic environments. These closures must attain lengths and widths of several kilometres before they can contain economically significant amounts of hydrocarbons. The growth kinematics of such large structures differ in some respects from those of geometrically similar, but smaller structures. Key aspects of the kinematics of large-scale fold structures are described, illustrated by new palaeomagnetic data from an example in the Salt Range of Pakistan. A numerical model describing the geometry of four-way dip closure is developed, relating the bulk volume to tangible geological parameters (limb dip, fold amplitude). An understanding of growth kinematics enables the application of a ‘fold test’, which provides a restoration of the palaeomagnetic data and host beds back to their attitudes at the time of magnetization. Comparison of the restored data with magnetic directions of known ages reveals the time of magnetization, so the geometry of the structure, including bulk volume at a known time, can be estimated. These data enable a curve describing the evolution of bulk volume through time to be calculated, which can be compared with the burial history of local source rocks — hence the trap volume available at the time of hydrocarbon generation can be estimated.
Searching for extinction/recovery gradients: the Frasnian-Famennian interval, Mokrá Section, Moravia, central Europe
Authors: Čejchan Petr , Hladil Jindřich 
Published: April 2008

Abstract

A series of ancient seafloors colonized by diverse organisms has been documented from the Upper Devonian rocks of the Western Mokrá Quarry. Situated in the southern tectonic closure of the Moravian Karst, the Frasnian-Famennian shallow carbonate ramps exhibit both Rhenish and Ukrainian affinities. Reconstruction of palaeo-sea floor horizons results in a series of 28 quadrats sufficient for further evaluation. Eighty-five taxa involved were scrutinized for abundance, occupied area, skeletal mass production and biomass production. The aim of the study was to determine whether the observed sequence of quadrats can be distinguished from a random one, and to discover any possible unidimensional gradient as a latent control. Monte Carlo simulations and a graph theoretical approach were utilized. Although the raw data seemed chaotic, the simulations demonstrated the observed sequence is not random. A significant influence of a hidden control is thus suggested. Fifteen characteristics of quadrats (e.g. diversity, number of taxa, vertical stratification of community, number of patches) were utilized for final interpretation. The gradient reconstructed by TSP algorithm reveals a significant crisis within the uppermost part of the
Amphipora
-bearing limestone.
Recovery of the marine fauna in Europe after the end-Triassic and Early Toarcian mass Extinctions
Authors: Hallam A. 
Published: April 2008

Abstract
A detailed analysis of species diversity increase, zone by zone up the Liassic section in northwest Europe, has been undertaken for the six fossil groups for which adequate data are available: bivalves, ammonites, rhynchonellid brachiopods, crinoids, foraminifera and ostracods. The general pattern is of a rapid increase through the Hettangian from a very low level after the end-Triassic mass extinction, followed by a slower rate of increase until the late Pliensbachian. Thereafter there was a drastic fall in the early Toarcian as a consequence of the mass extinction of that time, followed by a further rise continuing into the Middle Jurassic. A more general study takes into account data from southern Europe and extra-European localities, the best of which for the Liassic being in Argentina and Chile. The best data come from brachiopods and bivalves. The brachiopod pattern is similar to that described above for a more limited geographical region, with genera already occurring in the Hettangian and Sinemurian of southern Europe spreading into northwest Europe in the Pliensbachian. The bivalve data show that genera present in the Sinemurian and Pliensbachian of South America did not reach Europe until after the late Toarcian and early Middle Jurassic. Reef ecosystems, which were drastically affected by the end-Triassic mass extinction, did not re-establish themselves until the Pliensbachian; the early Toarcian event had a similarly deleterious effect.
There is a good correlation between the Hettangian to Pliensbachian diversity rise and rise of sea level, with the very low diversity values of the early Hettangian being associated with widespread dysoxic and anoxic conditions. The low diversities of the early Toarcian are also associated with anoxia correlated with a rapid sea-level rise, with the immigration into Europe of South American taxa taking place subsequently when environmental conditions ameliorated and the higher sea level permitted freer communication, most probably through the Hispanic Corridor across the present Central Atlantic region.
Foraminiferal recovery after the mid-Cretaceous oceanic anoxic events (OAEs) in the Cauvery Basin, southeast India
Authors: Tewari A. , Hart M. B. , Watkinson M. P. 
Published: April 2008

AbstractThe Cauvery Basin, SE India, is one of the best exposed late Mesozoic to Tertiary basins in India. The study of foraminiferal assemblages from the core samples obtained from two 120m deep wells in the basin records the occurrence of two mid-Cretaceous anoxic events in the basin. Abrupt increases in planktonic: benthonic ratios and reductions in benthonic diversity are recorded in the late Albian and in the late Cenomanian-early Turonian. These events coincide with worldwide oceanic anoxic events (OAEs).The OAEs had an impact on the microfauna of the basin, with approximately 35–45% of the benthonic species not surviving and major morphological changes occurring in the planktonic community. The late Cenomanian-early Turonian event was more significant than the late Albian event, with considerable readjustments occurring in the planktonic foraminifera. The genusRotaliporadisappeared and the genusHedbergellawas largely replaced byWhiteinella. Marginotruncanaappeared for the first time and theDicarinellapopulation expanded considerably.Praeglobotruncanawas the most tolerant genus, undergoing least change. The planktonic foraminifera evolved from small, weakly ornamented forms with poorly developed keels, into robust, well ornamented forms with well developed keels. The pattern of evolution of planktonic foraminifera suggests a recolonization of deeper water environments after the late Cenomanian-early Turonian anoxic event.
Recovery of the food chain after the Late Cenomanian extinction event
Authors: Hart M. B. 
Published: April 2008

Abstract

The Late Cenomanian bio-event is accepted as a globally synchronous extinction event that is characterized by significant biological changes which are coincident with isotopic and geochemical anomalies. The extinction event is characterized by changes on the macro-, meio-, micro- and nanno-scale and, in many examples, it has been suggested that these are ‘step-wise’. In the United Kingdom successions the steps are emphasized by depositional non-sequences, but in all cases the biological changes are in the same order. In microfaunal terms this involves a marked reduction in the benthonic foraminifera followed closely by a restriction of the planktonic foraminifera to surface-dwelling morphotypes. The event is also characterized by short-lived floods of
Heterohelix
sp. (small, biserial planktonic foraminiferids),
Bulimina
sp. (small, benthonic foraminiferids often characteristic of low-oxygen environments, calcispheres (?calcified dinoflagellates) and radiolaria. Following the extinction events, in the very latest Cenomanian, the recovery phase begins. Almost immediately the calcareous nannoplankton flora is restored but the dinoflagellates do not recover until much later in the Turonian. The benthonic foraminifera recover slowly with the fauna of the Early Turonian being of low diversity, with long-ranging taxa — including a large (?deep water), internally complex, agglutinated genus (
Labyrinthidoma
). The planktonic foraminifera recovered quickly with the
Praeglobotruncana, Dicarinella
, and
Marginotruncana
faunas appearing in succession within 100 000–200 000 years of the end of the extinction event. Using a model of the normal food chain it is possible to identify the order in which the basic building blocks needed for ecosystem recovery are put in place following the extinction event.
Recovery of Turonian dinoflagellate cyst assemblages from the effects of the oceanic anoxic event at the end of the Cenomanian in southern England
Authors: Fitzpatrick M. E. J. 
Published: April 2008

Abstract
The oceanic anoxic event during the latest Cenomanian caused the decline and temporary extinction of many species of marine micro-flora and -fauna. Many of these species reappeared during the Turonian. The recovery of the marine phytoplankton population after the oceanic anoxic event is examined. Detailed sampling of Turonian sediments from Kent, Sussex and the Isle of Wight (southern England) was undertaken to analyse the changes in the dinoflagellate cyst assemblages through time. Chalk, marl and flint samples were collected with no bias. Abundance and diversity of the assemblages varies greatly between sections and samples. Assemblages at the base of the Turonian (the Melbourn Rock Beds) are poor to barren. This is attributed to the lasting effect of the latest Cenomanian oceanic anoxic event. There is a general increase in diversity and abundance upwards through the succession, although assemblages never reach the richness that is seen in other Cenomanian sections.
Post-crisis recovery of Campanian desmoceratacean ammonites from Sakhalin, far east Russia
Authors: Yazykova Elena A. 
Published: April 2008

Abstract
The Santonian-Campanian boundary in Sakhalin marks a major Cretaceous mass extinction event. In the late Santonian there was a decrease in the taxonomic diversity of ammonoids as well as significant changes in shell morphology which were probably related to a global regression event. However, the fauna of the Pacific region is endemic and precise correlation between the Pacific and European regions is impossible. In this paper the stratigraphic position of the boundary between the Santonian and Campanian in Sakhalin is revised and the post-crisis recovery of the ammonoid diversity is discussed. Detailed sampling of the Santonian-Campanian sequence of Sakhalin (Naiba section, Orlovka section and others) allows identification of the phyllogenetic links between the different ammonite morphotypes in the pre-crisis communities. Comparison with adjacent regions in northeast Russia and Japan is also attempted. The ammonite extinctions at the Santonian-Campanian boundary are a good marker for stratigraphic correlation. During the crisis event ammonites of the superfamilies Acanthocerataceae and Desmocerataceae were affected most strongly whereas phylloceratids and lytoceratids were not significantly changed at that time. Heteromorphic ammonites are not discussed here. The pre-crisis community is characterized by a predominance of Acanthocerataceae, while the Desmocerataceae had a subordinate role. Representatives of these two groups form a community with large-size shells and strong ornamentation and this is not seen in the ammonites of the post-crisis community. The maximum occurrence of the Superfamily Desmocerataceae is recorded in the Middle Campanian, when the first diversification occurred (Family Pachydiscidae). Zonal correlation of the Santonian to Campanian succession of northeast Russia and Japan is discussed.
Extinction and survivorship of southern Tethyan Benthic foraminifera across the Cretaceous/Palaeogene boundary
Authors: Speijer R. P. , Van Der Zwaan G. J. 
Published: April 2008

AbstractThe benthic foraminiferal record from the Cretaceous/Palaeogene boundary stratotype of El Kef, Tunisia, shows a succession of three distinct assemblages. The late Maastrichtian upper bathyal assemblage is highly diversified and shows no prominent signs of gradual change towards the boundary. The earliest Palaeocene is marked by the disappearance of more than 50% of the taxa, resulting in a strongly impoverished fauna, tolerant to low oxygen conditions and with a shallower water affinity. Sequential (re-) appearance of many taxa in the early Palaeocene signifies the restoration towards normal Palaeocene upper bathyal faunas. The faunal changes reflect major perturbations in redox and trophic conditions at the sea-floor.At least locally, and perhaps even on a regional Tethyan scale, the extinctions can be related to a sharp decrease in oxygen supply, in combination with strongly reduced nutrient resources. It is suggested that a prolonged reduction in surface fertility and food flux to the sea-floor invoked worldwide (but diachronous) benthic extinctions. In particular endo-benthic deposit feeders and other taxa adapted to high and perhaps heterogeneous nutrient resources suffered extinction.
Recovery of the naticid gastropod predator-prey system from the Cretaceous-Tertiary and Eocene-Oligocene extinctions
Authors: Kelley Patricia H. , Hansen Thor A. 
Published: April 2008

Abstract
Naticid gastropods have been important shell-drilling predators of molluscs since the Cretaceous. Preliminary compilations of drilling frequencies by Vermeij (1987) were used to support his hypothesis of escalation, involving temporal increase in the hazard of predation and in adaptation to this hazard.
A comprehensive survey of naticid predation on molluscs in the Cretaceous and Palaeogene of the North American Coastal Plain revealed a complex pattern of escalation influenced by mass extinctions and recoveries. Data from more than 46 000 specimens from 17 formations show that dynamics of the naticid predator-prey system were affected significantly by the Cretaceous-Tertiary and Eocene-Oligocene mass extinctions. In the Cretaceous, drilling was low for gastropod prey (4–6%) and moderate for bivalves (13–19%). Drilling frequencies significantly increased above the K/T boundary in an initial recovery phase that lasted no more than 1–3 Ma. Recovery from the Eocene-Oligocene extinction also involved a significant increase in drilling, especially on bivalves (from 8% to 24%).
Based on these data (and similar patterns reported for fossil ostracode prey), we propose a model of cyclic escalation of the naticid predator-prey system, in which mass extinctions perturb the system and initiate cycles. Drilling frequencies in recovery faunas are greatly increased, possibly owing to preferential extinction of highly escalated prey. As the recovery proceeds, escalation of prey defences causes drilling frequencies to stabilize or decline. Reorganization of the predator-prey system also involves reduction in predator behavioural stereotypy after mass extinctions, followed by gradual recovery.