bluuebunny/crossref_metadata_2025_split huggingface dataset:
The relationship between 1.88 Ga old magmatism and the Baltic-Bothnian shear zone in northern Sweden
Authors: Wikström A. , Skiöld T. , Öhlander B. 
Published: April 2008

Abstract
New geochemical data and U-Pb ages for Proterozoic mafic and felsic dykes and their granitic host rocks in the Bläsberget Massif, proximal to the Baltic-Bothnian shear zone, indicate that these rocks are part of a terrane distinct from Svecofennian terranes in Central and Southern Sweden. The dykes comprise a NNE-trending swarm which can be traced over a strike length of about 20 km. Most of the mafic dykes are internally deformed and have systematic internal structures showing a sinistral horizontal component and an eastern-side-up sense of movement. This sinistral shearing is also observed within the nearby Baltic-Bothnian shear zone.

The mafic dykes have a uniformly basaltic composition. High content of elements such as Ti and Zr illustrate the typical ‘within-plate’ character. The felsic dykes are chemically homogeneous and have a SiO
2
content of about 77 wt%. High content of Y, Yb and Nb confirms the ‘within-plate’ character of the dyke swarm.

Zircons extracted from one of the felsic dykes indicate a U-Pb age of
c.
1.88 Ga. Approximately the same age has been obtained from the host rock granite and from a nearby occurrence of a similar late-orogenic granite. Since the dykes cross-cut most deformation and migmatite structures and most likely represent the waning stages of orogenic deformation in the area, it is evident that the timing of the orogenic events in the area is different and older than the Svecofennian development in central and southern Sweden.

A genetic relationship is suggested between the magmatism and the development of the Baltic-Bothnian shear zone.
Mesoproterozoic anorogenic magmatism in southern Norway
Authors: Menuge J. F. , Brewer T. S. 
Published: April 2008

Abstract

The 1500 Ma Rjukan Group of the Telemark Supracrustal Suite, south Norway, consists of a metamorphosed sequence of acid volcanic rocks (Tuddal Formation) overlain by a comparable thickness of metabasalts (Vemork Formation). Both acid and basic volcanic rocks have within-plate chemical compositions. The acid rocks have initial ε
Nd
values of 1.0 to 4.5, similar to the isotopic signature of some components of the Telemark gneiss complex, which is the probable basement to the Telemark Supracrustal Series. The metabasalts have initial ε
Nd
values of 3.0 to 4.3, indicating a depleted mantle source region. A mantle plume origin for the Rjukan Group is unlikely given the absence of high temperature igneous rocks such as picrites. Magma genesis by lithospheric extension following orogeny is therefore proposed, with the Tuddal Formation acid magmas derived by anatexis of arc-generated crustal rocks 1500–2000 Ma old, whilst the Vemork Formation basaltic magmas were derived by decompression mantle melting. The Rjukan Group is correlated with the granite-rhyolite province of the US midcontinent, implying large-scale continental rifting. The substantial volume of basic volcanic rocks suggests greater or more prolonged extension in south Norway than in North America.
Thermotectonic evolution of the Eastern Segment of southwestern Sweden: tectonic constraints from U-Pb geochronology
Authors: Connelly J. N. , Berglund J. , Larson S. Å. 
Published: April 2008

Abstract
The Eastern Segment forms a complex crustal terrane that occupies the southeastern part of the Southwest Scandinavian Domain adjacent to the less deformed 1.65–1.85 Ga Transscandinavian Igneous Belt (TIB). New U-Pb data from the Eastern Segment indicate that orthogneisses and granitoid rocks have protolith ages equivalent to the later magmatic phases of the TIB and that the earliest thermotectonic episodes in the Eastern Segment occurred between 1.70 and 1.61 Ga during the Gothian Orogeny. The comparable ages for Eastern Segment gneisses and TIB rocks represent permissive evidence for the hypothesis that the orthogneiss protoliths intruded into the western margin of Fennoscandia and are not exotic with respect to the pre-Gothian craton.
The eastern limit of Gothian deformation is thus interpreted to be an intracratonic deformation front that coincides with the later Sveconorwegian deformation front along the Protogine Zone south of Lake Vänern. The post-Gothian anorogenic period was interrupted, in at least the eastern part of the Eastern Segment, by a thermal and magmatic event at 1.47 Ga that generated granitic dykes and (re)crystallized titanite. Sveconorwegian U-Pb ages and field observations are compatible with a thrusting and exhumation of western supracrustal terranes over the Eastern Segment during the Sveconorwegian Orogeny, followed by isostatic unroofing and cooling of the lower deck at 950–930 Ma. Available, albeit limited, Sveconorwegian titanite ages in the Eastern Segment young from east to west, ranging from 950 to 930 Ma, and are substantially younger than those dated in the western terranes of SSD.
The provenance of pre-Scandian continental flakes within the Caledonide Orogen of south-central Norway
Authors: Emmett Trevor F. 
Published: April 2008

Abstract

A significant portion of the Caledonian nappe pile of south-central Norway is composed of tectonic flakes of continental crust older than the arkosic sediments of the Upper Precambrian-Lower Cambrian Hedmark and Valdres Groups. Models deriving these flakes from a suture zone S and SE of the Western Gneiss Region have found less favour than those deriving them from a root zone lying off the present-day coast line to the NW. Recent models propose that the largest flake, the Jotun-Valdres Nappe Complex, is a microcontinental suspect terrane structurally bounded above and below by ophiolitic sutures. The pre-Caledonian geological evolution of the Jotun-Valdres Nappe Complex and the Bergen Arcs is shown to be comparable to that of adjacent parts of the autochthonous Fennoscandian Shield, and to a putative root zone along strike from the Lofoten-Vesterålen Province. It is concluded that the Jotun-Valdres Nappe Complex and, by implication, related units in the Bergen Arcs and elsewhere, are not ‘suspect’ and are portions of the Mid to Late Proterozoic Baltoscandian crust, detached and thrust into position during the
c.
390 Ma Scandian (= late-Caledonian) orogenic event.
Stream sediment, soil and forage chemistry as indicators of cattle mineral status in northeast Zimbabwe
Authors: Fordyce F. M. , Masara D. , Appleton J. D. 
Published: April 2008

Abstract
Results of previous studies investigating the use of soil and forage chemistry as indicators of cattle mineral status have been somewhat equivocal, possibly due to the limited range of trace element concentrations in the areas investigated. This paper describes an investigation of the relationship between trace element concentrations in stream sediments, soils, forage (grass and leaves) and cattle blood (serum) in northeast Zimbabwe in order to identify which, if any, of the sample media provide a reliable guide to cattle mineral status. Soil, forage and cattle serum were collected from an area characterized by a wide range of Zn in stream sediments. The area was subdivided into three regions of relatively low, medium and high Zn concentration on the basis of stream sediment data and variations in the chemistry of cattle serum, forage, soil and stream sediment samples were examined. Significant correlations exist between element concentrations in stream sediments, soils and forage but there are no significant correlations with cattle serum. Although this lack of direct correlation may, in part, be due to a range of biological factors, it is suggested that high concentrations of Fe in soil and forage inhibit (i) the availability of P to plants and (ii) the absorption of Cu and Zn in cattle. This may have wide ranging implications due to the predominance of ferrallitic soils in many countries in tropical regions.
The environmental geochemistry of aluminium in tropical terrains and its implications to health
Authors: Smith B. , Breward N. , Crawford M. B. , Galimaka D. , Mushiri S. M. , Reeder S. 
Published: April 2008

Abstract
The link between environmental exposure to aluminium, mammalian toxicity and agricultural productivity has focused attention on the relationship between the environmental geochemistry of Al and its potential toxicity. Recent work has questioned the accuracy of previously reported baseline levels of aluminium in tropical well waters. In this work we investigate the validity of these observations and their influence on criteria for the determination of water quality.

Data are presented for two contrasting study areas in Uganda in which
c.
50 water samples were collected from a variety of water sources and subsequently analysed to identify concentrations of dissolved Al and of ligands that potentially control its environmental mobility and toxicty. Determinands included: pH, temperature, redox potential, conductivity, alkalinity, major and trace cations and anions and TOC.

Determination of Al by ICP-AES before and after sonication confirmed that sonication of samples filtered to 0.40 μm during sampling resulted in increased Al concentrations in solution. This effect is considered to be consistent with the aggregation of a non-labile colloidal Al on the addition of acid and confirms observations made by other researchers in Malawi. However, on-site analysis of samples using pyrocatechol violet indicated negligible free or labile Al present in the sampled waters and suggests that the majority of Al undetected by routine ICP-AES analysis is present in a non-labile form of relatively low potential toxicity.
Sources and pathways of arsenic in the geochemical environment: health implications
Authors: Thornton Iain 
Published: April 2008

Abstract

Arsenic is ubiquitous in the environment, being present in small amounts in all rock, soil, dust, water and air. It is associated with many types of mineral deposits and in particular those containing sulphide minerals. The most common arsenic mineral is arsenopyrite, FeAsS
2
. Elevated concentrations are sometimes found in fine grained argillaceous sediments and phosphorites. Some marine sediments may contain as much as 3000 mg kg
−1
. Arsenic is co-precipitated with iron hydroxides and sulphides in some sedimentary rocks, and is precipitated as ferric arsenate in soil horizons rich in iron.

This paper reviews current knowledge on the natural geochemical sources of arsenic in several countries where high concentrations in soils, dusts, surface and groundwaters may present a hazard to human health. The chemistry and behaviour of arsenic within the weathering zone are discussed in relation to pathways leading to human exposure.
Mobility of arsenic in groundwater in the Obuasi gold-mining area of Ghana: some implications for human health
Authors: Smedley P. L. , Edmunds W. M. , Pelig-Ba K. B. 
Published: April 2008

Abstract

Arsenic in drinking water from streams, shallow wells and boreholes in the Obuasi gold-mining area of Ghana range between < 2 and 175 μgl
−1
. The main sources are mine pollution and natural oxidation of sulphide minerals, predominantly arsenopyrite (FeAsS). Streamwaters have been most affected by mining activity and contain some of the highest As concentrations observed. They are also of poor bacteriological quality. Some of the streams have a high As(III) content (As(III)/As
total
> 0.5), probably as a result of methylation and reduction reactions mediated by bacteria and algae. Concentrations of As in groundwaters reach up to 64 μgl
−1
, being highest in deeper (40–70 m) and more reducing (220–250 mV) waters. The As is thought to build up as a result of the longer residence times undergone by groundwaters in the deeper parts of the aquifer. The proportion of As present as As(III) is also higher in the deeper groundwaters. Deep mine exploration boreholes (70–100 m) have relatively low As contents of 5–17 μgl
−1
, possibly due to As sorption onto precipitating ferric oxyhydroxides or to localized low As concentrations of sulphide minerals.

Median concentrations of inorganic urinary As from sample populations in two villages, one a rural streamwater-drinking community and the other a suburb of Obuasi using groundwater for potable supply, were 42 μgl
−1
and 18 μgl
−1
respectively. The value for the community drinking groundwater is typical of background concentrations of urinary As. The slightly higher value for the streamwater-drinking community probably reflects different provenance of foodstuffs and higher As concentrations of water sources local to the village. The low value obtained for the inhabitants of the Obuasi suburb, living close to and abstracting groundwater from the area of major mining activity, suggests that groundwater can form a useful potable supply of good inorganic quality provided that deep, long residence time sources are avoided.
Environmental impact of mining and smelting industries in Poland
Authors: Helios Rybicka E. 
Published: April 2008

Abstract

Mining and smelting industries cause tremendous devastation of both terrestrial and aquatic environments on the local and regional scale. Mines and smelters produce large quantities of waste, which must be deposited on land or into aquatic systems. The major effects in terms of contamination by heavy metals are in the pollution of air, soil, river water and groundwater systems. In Poland the most endangered surface water systems are the upper courses of both the Vistula and Odra Rivers, where the increase of contaminants, especially heavy metals and chloride ions, must be regarded as alarming. About 50% of surface water flows do not even meet the standards for quality class III. In 1990 the volume of wastes produced by mining and processing industries was more than 660 million tonnes of spoils and 490 million tonnes of tailings. It is estimated that in the period 1984–2000 about 900 million m
3
of spoils will be dumped in the area of the Upper Silesian Coal Basin alone. Taking into account the volume of sewage which should be treated, the emission of dusts and gases, and the volume of dumped wastes per km
2
, 27 ecologically endangered regions have been distinguished. Almost half of these correspond to mining and smelting districts.
Lacustrine sediment geochemistry as a tool in retrospective environmental impact assessment of mining and urban development in tropical environments: examples from Papua New Guinea
Authors: Nicholson Keith 
Published: April 2008

Abstract
Lake sediments represent an archive on chemical inputs into the environment. Baseline data for natural or background inputs can be obtained by analysis of deep (> 1 m) cores in conjunction with rigorous statistical procedures such as probability plots. Surface sediments illustrate the geographical distribution of the contamination, while shallow cores (< 1 m) permit estimates of sedimentation rate from the onset of contamination discharge. In Papua New Guinea lakes are particularly important as fish stocks which represent a vital source of protein, and any impact which may diminish these stocks is a cause for concern. Two lakes considered are respectively impacted by mining and urban development and show significant enrichments in metals and enhanced sedimentation rates. Surface enrichments in Cu in the mining-impacted lake attain levels of 348% over baseline; while the lake impacted by urban run-off and sewage discharge displays enrichments of 450% for Pb, 500% for Mn and 1100% for P. Sedimentary geochemistry is a potential tool in determining background or ‘natural’ metal inputs into a lacustrine system. Such data can permit environmental impact evaluations and legislative guidelines to be developed retrospective to development. In developing countries where urban and industrial growth has preceded environmental legislation, this technique may be employed to provide baseline data on which future discharge limitations or environmental controls may be built.
Clinical and epidemiological correlates of iodine deficiency disorders
Authors: Stewart A. G. , Pharoah P. O. D. 
Published: April 2008

Abstract
The iodine deficiency disorders, endemic goitre, stillbirths, abortions, congenital abnormalities, endemic cretinism, and impaired mental function, are found worldwide. Known for millenia, they currently put 29% of the world’s population at risk. The most important is cretinism, found in two forms. Neurological cretinism possibly develops due to an insult in early pregnancy, hypothyroid cretinism to an insult late in pregnancy or in early life.
The classical medical causes of environmental iodine deficiency, glaciation and leaching, do not adequately explain the prevalence and distribution of iodine deficiency disorders, nor have the new insights into the environmental chemistry of iodine been assimilated properly with medical knowledge. Joint studies would be of help.
The presence of various factors other than iodine deficiency in the causation of the disorders is recognized. These are often thought to be geologically related. Recent work suggests plate tectonics as the unifying factor, since iodine deficiency disorders are found along many plate collision zones. Concentration of major and trace elements as a result of plate subduction provides a possible source of goitrogens. A systematic search is needed.
The iodine goitrogen ratio could provide the link between environmental iodine and differing intensities of the iodine deficiency disorders found in affected communities.
A review of the geochemical factors linked to podoconiosis
Authors: Harvey R. , Powell J. J. , Thompson R. P. H. 
Published: April 2008

Abstract
Podoconiosis, or non-filarial elephantiasis, was named and characterized by the late Ernest Price (Price 1988, 1990). He described the clinical features of swelling and deformity of the legs associated with enlargement of the draining lymph nodes. Histopathological examination of these nodes showed them to contain bi-refringent particles. He identified the epidemiological association between the local type of soil and the disease, and finally he confirmed this association by microanalysis of the particles in diseased tissue, showing them to be sub-micron aluminosilicate and silica, which are characteristics of the clay fractions of the local soil. It remains unclear what it is within the heterogeneous range of microparticles identified in tissue, and soil factors, that is responsible for the toxicity, and what are the host factors that determine certain individuals to be sensitive to them. Prevention of progression of the disease could be achieved by preventing further uptake of particles by using adequate footwear.
History of hydrocarbon exploration in the Moray Firth
Authors: David M. J. 
Published: April 2008

Abstract

Exploration drilling in the Moray Firth commenced with the spudding of well 12/26-1 on 28 July 1967. From then until April 1994 (study cut off date) some 402 exploration wells and 153 appraisal wells have been drilled, proving up an estimated 5332 × 10
6
BOE entrapped within reservoirs ranging in age from Devonian to Eocene. It is estimated that 3087 × 10
6
BOE of these reserves are contained within the sandstone reservoirs of the Upper Jurassic.

The discovery of oil in the Witch Ground Graben, principally the Piper (1973) and the Claymore field (1974), not only established another new play in Upper Jurassic reservoirs for the United Kingdom Continental Shelf, but breathed life into an area previously ‘downgraded’ in terms of Jurassic prospectivity, and drilled initially for its Tertiary potential.
This paper reviews the history of hydrocarbon exploration in the Moray Firth. The author examines the main events that he feels have influenced exploration activity, the main play types that have been pursued, and the resulting distribution of reserves. Future potential is now believed to lie in the downthrown play at Upper Jurassic level in the Outer Moray Firth.
Genetic stratigraphy and sandstone distribution of the Moray Firth Humber Group (Upper Jurassic)
Authors: Harker S. D. , Rieuf M. 
Published: April 2008

Abstract

Upper Jurassic sandstones are of great economic importance in the Moray Firth, where 22 known fields originally contained almost three billion barrels of oil reserves. Principles of genetic stratigraphy provide the basis for recognition, correlation and mapping of eight Moray Firth Humber Group units. Genetic unit boundaries, which are biostratigraphically constrained, represent marine flooding surfaces or unconformities that resulted principally from tectonic/erosional episodes. Tectonic evolution in the Late Jurassic consisted of pre-rift and syn-rift phases, with accompanying differences in facies associations and sandstone distribution. Pre-rift sandstones comprise regressive pulses within a predominant overall transgressive setting, a coal-bearing deltaic/paralic succession is commonly succeeded by shallow marine deposits. The transgression commenced in the Callovian in the west and shoreline facies migrated eastwards through into the Kimmeridgian (
sensu gallico
), toward the junction with the Central North Sea graben system. Syn-rift sandstones are mostly turbiditic in origin, deposited during episodic Late Cimmerian tectonism, that started in the late Kimmeridgian and continued through into the Early Cretaceous. Only isolated remnants of the shallow marine equivalents to these deep marine systems have been found to data, such as those of Volgian age in the Glamis field on the Fladen Ground Spur.
Contrasting mineralogy of Upper Jurassic sandstones in the Outer Moray Firth, North Sea: implications for the evolution of sediment dispersal patterns
Authors: Hallsworth Claire R. , Morton Andrew C. , Dore Graham 
Published: April 2008

Abstract
Upper Jurassic sandstones in and adjacent to UK North Sea Block 15/21 (Outer Moray Firth) contain heavy mineral assemblages that provide evidence for differences in provenance, sediment dispersal patterns and depositional histories between the Ivanhoe/Rob Roy Terrace, North Halibut Graben, South Halibut Graben and Tartan Ridge. Variations are demonstrated using provenance-sensitive parameters, including apatite/tourmaline ratios, monazite/zircon ratios and garnet compositions. Seven different sandstone types have been identified on this basis. Scott and Piper sandstones (late Oxfordian-early Kimmeridgian) have contrasting mineralogies, indicating that they were derived from different provenances. However, the two sandstone packages lack internal stratigraphic variations, indicating that each is relatively homogeneous in terms of sediment supply. The succeeding Claymore sandstones (late Kimmeridgian-Volgian) display much greater variation, both regionally and stratigraphically. Heavy minerals suggest that the Main Claymore depositional system was more laterally extensive than that of the Upper Claymore, which was more locally developed and coalesced to a smaller degree. The most significant change in provenance took place with the onset of Main Claymore deposition, when the first major recycling of older Upper Jurassic sand took place. This indicates shedding of sediment from the Halibut Horst area, due either to uplift through intrabasinal tectonism or to a fall in sea level. Sediments in the South Halibut Graben contain minerals indicating exposure of granitic skarns on the Halibut Horst at this time. The area was compartmentalised in Upper Claymore times, with different dispersal systems operating north and south of the Halibut Horst, indicating that the horst continued to be an important control on sediment distribution.