bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resources for the city: sustainable use of bedrock resources for concrete production with examples from Sweden
Authors: Schouenborg B. , Tang L. , Åkesson U. 
Published: December 2009

Abstract
Rock aggregate products are essential for our infrastructure and society as a whole. Rock aggregates are mainly used for road and railroad construction and for the manufacture of asphalt and concrete. High-quality, low-cost, environmentally friendly rock aggregates and recycling of materials are important resources for the development of a sustainable society. The relative amount of crushed bedrock is steadily increasing, as a result of the joint effort by the authorities and industry to save natural gravel. It is important to support this trend by all possible means. One of the primary problems is the fact that the available resources of natural aggregates are diminishing in most of Europe. To protect the natural environment, the use of natural sand and gravel aggregates must be reduced and crushed aggregates, instead, will have to be used in concrete production in the future. The paper focuses on this problem and presents proposals for how to deal with it by co-operative research.
A perspective on the future of engineering geology in the world, Asia and Japan
Authors: Inoue D. , Oshima H. ,   JSEG Research Planning Committee,   JSEG International Committee
Published: December 2009

Abstract
The 21st century provides a turning point from the days of exploitation of natural resources and of infrastructure construction to the proper management of national lands to establish human coexistence with the environment. This paper mainly discusses the issues for the improvement of engineering geological activities of research, education and the provision of information in the future at a World, Asian and Japanese level. The authors believe that some of the issues may be commonly observed world-wide and the solutions to the problems should be sought by the international cooperation of engineering geologists. Engineering geology needs to be an autonomous field of science and should provide educational systems to foster engineering geologists who can work together on an equal footing with professionals from other disciplines.
Regional modelling of geohazard change
Authors: Rees J. G. , Gibson A. D. , Harrison M. , Hughes A. , Walsby J. C. 
Published: December 2009

Abstract
Society faces a future of unprecedented, extensive and rapid environmental change. The impacts of climate change and greater societal vulnerability will require far-reaching adaptations of behaviour and activity. To plan these, decision-makers require tools that will help them understand the extent and impact of natural hazards. These should take into account deterministic and probabilistic analyses of occurrence, impact, spatial distribution, background conditions and triggers that affect different hazards. Geographic information system (GIS)-based, 2D, models are easily understood by different users and are well suited to situations where data is plentiful, the historical record is relatively complete or where problems are simple. However, they have limitations. Advances in computer processing capacity have brought marked changes in how data can be manipulated and presented; this has allowed and driven an increasing desire to provide more detailed information about the spatial extent, temporal occurrence, triggers and impacts of geohazards. Future geohazard models based on 3D distributions of causative factors, including primary (e.g. precipitation) and secondary (e.g. groundwater) 4D processes, that determine the timing, scale and geographical distribution of events will rapidly evolve. They will increasingly integrate data from other disciplines, such as societal vulnerability, to develop risk models. Currently, geohazard models are constrained by inadequate data, a poor understanding of the interaction of processes, and cultural barriers such as inertia or intellectual property rights. The development of improved models, whether for planning purposes or management of crises, provides challenges, both in system development and in the communication of complexity and uncertainty with decision-makers.
Planning and geohazards
Authors: Gibson A. D. , Chowdhury R. 
Published: December 2009

Abstract

This paper reviews the work of 56 papers, authored by scientists and engineers from 60 different countries. The methods and achievements shown by this collection of papers are compared to a similar review made in 1998. Some similarities were remarkable:

The most prominent hazards in both reviews were earthquakes, volcanoes, slope instability and subsidence;

Slow onset events were rarely discussed;

Both reviews report exacerbation of natural risks by rapid development, water abstraction or lack of maintenance;

New development continues to be located in marginal areas such as unstable slopes, flood-prone alluvium or coastal plains, with decisions on development driven by political or socio-economic factors that sometimes outweigh geoscientific advice.

However, there were a large number of notable advances that continue to drive engineering geology forward including:

The advent of GIS and 3D computer modelling;

The availability of data online;

An increasing adoption of risk methodologies to aid decision making where geological, geotechnical, sociological, economic and procedural data are built into event scenarios and assessed by professional judgement.

There was some indication from conference that, as hypothesized by
Knill (2003)
and
Culshaw (2005)
, the engineering geology profession continues in a process of ‘synthesis’ whereby the profession is gaining influence upon planning decisions and policy. Some sectors, notably radon, volcanic and seismic management, have shifted the
presentation
of their research to take better account of societal vulnerability and management. As a result, geoscience expertise in radon and seismic hazards is increasingly integrated with planning procedures. Although this ‘evolution’ is perhaps more difficult for more localized geohazards such as landslides or karst, there was good indication that such a shift is underway.
Urban site investigation
Authors: Clayton C. R. I. 
Published: December 2009

Abstract
This paper provides a written version of a Keynote Presentation made at the 10th International Congress of the Association for Engineering Geology and the Environment (IAEG), held in Nottingham in September 2006. It identifies the objectives of site investigation, as stated in the British Standard. It then reviews the difficulties that face the investigator, and identifies factors that have in the UK been found to have an influence on the success of site investigations. Developments in general UK ground investigation strategy are outlined. The challenges of urban site investigations are identified, as is the vulnerability of urban development. Recent advances in investigation techniques are described, and conclusions drawn.
U-Pb zircon geochronology of Palaeozoic units in Western and Central Guatemala: insights into the tectonic evolution of Middle America
Authors: Solari L. A. , Ortega-Gutiérrez F. , Elías-Herrera M. , Schaaf P. , Norman M. , de león R. Torres , Ortega-Obregón C. , Chiquín M. , ical S. Morán 
Published: December 2009

Abstract

Precambrian and Palaeozoic basements are present in southern Mexico and Central America, where several crustal blocks are recognized by their different geological record, and juxtaposed along lateral faults. Pre-Mesozoic reconstructions must take into account the nature of such crustal blocks, their geological history, age and petrology. Some of those crustal blocks are currently located between southernmost north America (the Maya Block) and Central America (Chortís Block).To better understand the geology of these crustal blocks, and to establish comparisons between their geological history, we performed U–Pb dating of both igneous and metasedimentary key units cropping out in central and western Guatemala. In the Altos Cuchumatanes (Maya Block) granites yield both Permian (269±29 Ma) and Early Devonian (391±7.4 Ma) U–Pb ages. LA-ICPMS detrital zircon ages from rocks of the San Gabriel sequence, interpreted as the oldest metasedimentary unit of the Maya Block, and overlain by the Late Palaeozoic Upper Santa Rosa Group, yield Precambrian detrital zircons bracketed between
c
. 920 and
c
. 1000 Ma. The presence of these metasedimentary units, as well as Early Devonian to Silurian granites in the Mayan continental margin, from west (Altos Cuchumatanes), to east (Maya Mountains of Belize) indicates a more or less continuous belt of Lower Palaeozoic igneous activity, also suggesting that the continental margin of the Maya Block can be extended south of the Polochic fault, up to the Baja Verapaz shear zone. A metasedimentary sample belonging to the Chuacús Complex yielded detrital zircons with ages between
c
. 440 and
c
. 1325 Ma. The younger ages are similar to the igneous ages reported from the entire southern Maya continental margin, and show proximity of the Complex in the Middle-Late Palaeozoic. The S. Diego Phyllite, which overlies high-grade basement units of the Chortís Block, contains zircons that are Lower Cambrian (
c
. 538 Ma), Mesoproterozoic (
c
. 980 to
c
. 1150 Ma) and even Palaeoproterozoic (
c
. 1820 Ma). Absence of younger igneous zircons in the San Diego Phyllite indicates that either its sedimentation took place in a close range of time, during the Late Cambrian, or absence of connection between Chortís and Maya Blocks during the Early–Mid-Palaeozoic. The Precambrian zircons could have come from southern Mexico (Oaxaca and Guichicovi Complexes), or from Mesoproterozoic Massifs exposed in Laurentia and Gondwana. Palaeogeographic models for Middle America are limited to post-Jurassic time. The data presented here shed light on Palaeozoic and, possibly, Precambrian relationships. They indicate that Maya and the Chortís did not interact directly until the Mesozoic or Cenozoic, as they approached their current position.
Geochemistry and tectonomagmatic significance of Lower Cretaceous island arc lavas from the Devils Racecourse Formation, eastern Jamaica
Authors: Hastie Alan R. , Kerr Andrew C. , Mitchell Simon F. , Millar Ian L. 
Published: December 2009

Abstract

The Benbow Inlier in Jamaica contains the Devils Racecourse Formation, which is composed of a Hauterivian to Aptian island arc succession. The lavas can be split into a lower succession of basaltic andesites and dacites/rhyolites, which have an island arc tholeiite (IAT) composition and an upper basaltic and basaltic andesite sequence with a calc-alkaline (CA) chemistry. Trace element and Nd–Hf isotopic evidence reveals that the IAT and CA lavas are derived from two chemically similar mantle wedge source regions predominantly composed of normal mid-ocean ridge-type spinel lherzolite. In addition, Th-light rare earth element/high field strength element–heavy rare earth element ratios, Nd–Hf isotope systematics, (Ce/Ce*)

n-mn

and Th/La ratios indicate that the IAT and CA mantle wedge source regions were enriched by chemically distinct slab fluxes, which were derived from both the altered basaltic portion of the slab and its accompanying pelagic and terrigenous sedimentary veneer respectively. The presence of IAT and CA island arc lavas before and after the Aptian–Albian demonstrates that the compositional change in the Great Arc of the Caribbean was the result of the subduction of chemically differing sedimentary material. There is therefore no evidence from the geochemistry of this lava succession to support arc-wide subduction polarity reversal in the Aptian–Albian.
Late Cretaceous to Miocene seamount accretion and mélange formation in the Osa and Burica Peninsulas (Southern Costa Rica): episodic growth of a convergent margin
Authors: Buchs David Marc , Baumgartner Peter Oliver , Baumgartner-Mora Claudia , Bandini Alexandre Nicolas , Jackett Sarah-Jane , Diserens Marc-Olivier , Stucki Jérôme 
Published: December 2009

AbstractMultidisciplinary study of the Osa and Burica peninsulas, Costa Rica, recognizes the Osa Igneous Complex and the Osa Mélange – records of a complex Late Cretaceous–Miocene tectonic–sedimentary history. The Igneous Complex, an accretionary prism (sensu stricto) comprises mainly basaltic lava flows, with minor sills, gabbroic intrusives, pelagic limestones and radiolarites. Sediments or igneous rocks derived from the upper plate are absent. Four units delimited on the base of stratigraphy and geochemistry lie in contact along reactivated palaeo-décollement zones. They comprise fragments of a Coniacian–Santonian oceanic plateau (Inner Osa Igneous Complex) and Coniacian–Santonian to Middle Eocene seamounts (Outer Osa Igneous Complex). The units are unrelated to other igneous complexes of Costa Rica and Panama and are exotic with respect to the partly overthickened Caribbean Plate; they formed by multiple accretions between the Late Cretaceous and Middle Eocene, prior to the genesis of the mélange. Events of high-rate accretion alternated with periods of low-rate accretion and tectonic erosion. The NW Osa Mélange in contact with the Osa Igneous Complex has a block-in-matrix texture at various scales, produced by sedimentary processes and later tectonically enhanced. Lithologies are mainly debris flows and hemipelagic deposits. Clastic components (grains to large boulders) indicate Late Eocene mass wasting of the Igneous Complex, forearc deposits and a volcanic arc. Gravitational accumulation of a thick pile of trench sediments culminated with shallow-level accretion. Mass-wasting along the margin was probably triggered by seamount subduction and/or plate reorganization at larger scale. The study provides new geological constraints for seamount subduction and associated accretionary processes, as well as on the erosive/accretionary nature of convergent margins devoid of accreted sediments.
Accreted oceanic terranes in Ecuador: southern edge of the Caribbean Plate?
Authors: Jaillard Etienne , Lapierre Henriette , Ordoñez Martha , Álava Jorge Toro , Amórtegui Andrea , Vanmelle Jérémie 
Published: December 2009

Abstract

The western part of Ecuador is made from several oceanic terranes, which comprise two oceanic plateaus, of Early (
c
. 120 Ma) and Late Cretaceous age (
c
. 90 Ma), respectively. The older oceanic plateau was accreted to the Andean margin in the Late Campanian (
c
. 75 Ma). Fragments of the Turonian–Coniacian plateau were accreted to the Ecuadorian margin in the Late Maastrichtian (
c
. 68 Ma, Guaranda terrane) and Late Paleocene (
c
. 58 Ma, Piñón–Naranjal terrane). The Guaranda terrane received either fine-grained oceanic sediments of Coniacian–Maastrichtian age, or island arc/back-arc volcanic suites of Middle Campanian–Middle Maastrichtian age. The Piñón–Naranjal terrane recorded a comparable history, completed in the Maastrichtian–Paleocene, either by pelagic cherts, or by island arc products (Macuchi arc). The Late Cretaceous plateau of Ecuador is interpreted as part of the Caribbean oceanic plateau (COP), because their evolutions are comparable. If so, the COP was not formed by the Galápagos hotspot, but on the Farallón oceanic plate, south of Ecuador and close to the South American margin. The COP belonged to the Farallón plate, until a subduction zone separated both plates in the Middle Campanian, giving way to a well-developed Mid Campanian–Mid Maastrichtian island arc. Accretion in the Late Maastrichtian triggered a change in the subduction system, and the development of a new arc system of Late Maastrichtian–Late Paleocene age, which crosscut the South America–COP plate boundary. The last accretion occurred in the Late Paleocene.
Some remarks on the Caribbean Plate kinematics: facts and remaining problems
Authors: Giunta G. , Oliveri E. 
Published: December 2009

Abstract
Caribbean Plate margins are assemblages of terranes located, since the Mid-Cretaceous, along transform boundaries between the Caribbean, North and South America and the Pacific and Atlantic oceans. Litho-stratigraphic, petrological and metamorphic features of the main units and their regional correlations allow definition of the main geotectonic elements (continental margins, oceanic basins, subduction zones, magmatic arcs) involved in the evolution of Caribbean Plate margins. They provide valuable constraints on plate evolution since the Jurassic. This involved proto-Caribbean ocean opening, thickening into an oceanic plateau, beginning of convergence in the Early Cretaceous, atypical evolution of a supra-subduction system during the Mid-Cretaceous, subduction of rifted continental margins, Late Cretaceous convergence related to eastward migration of two opposite triple-junctions and strike–slip tectonics. Using these data, we compare different models and suggest improvements.
Caribbean-South America oblique collision model revised
Authors: Higgs Roger 
Published: December 2009

AbstractThe ‘Caribbean oblique collision model’ invokes a three-stage evolution for Ecuador–Colombia–Venezuela–Trinidad: (1) Jurassic rifting; (2) Oxfordian–Neogene passive margin subsidence beside the spreading (until Campanian) Proto-Caribbean Ocean; (3) Campanian to Miocene oblique collision of the Caribbean Arc from the west, producing a craton-verging thrust belt and foreland basin. The timing of these stages is incorrect. Rifting ended 70 Ma later (Coniacian), with Cuba breaking away from Venezuela–Trinidad. Brief Proto-Caribbean spreading (Santonian–Campanian) was followed by slow (amagmatic) subduction below Venezuela and Trinidad, driven by inter-Americas convergence, so the passive margin lasted just 10–15 Ma in eastern Venezuela, not 140 Ma (sic). Convergence changed from WSW to SSE in Paleocene time, causing Proto-Caribbean subduction under Colombia too. Subduction in Venezuela–Trinidad drove upper crustal nappes cratonward, metamorphosing overridden rift deposits of the Inner Nappe (Cordillera de la Costa) and feeding Campanian–Miocene olistostromes to aProto-Caribbean‘pre-arc’ foreland basin. The Caribbean Arc collided with Ecuador to Guajira from Campanian time and passed ‘Guajira corner’ in Early Oligocene time, not Paleocene, then migrated SE forming the Gulf of Venezuela–Falcón, diachronous (Oligo–Miocene), transform-related extensional basin, followed by oblique collision (obduction) in central Venezuela to Trinidad driving a Mio–PlioceneCaribbeanforeland basin. Caribbean relative motion switched to eastward near 2.5 Ma, not 12 Ma as is widely believed. The new plate boundary follows the Eastern Cordillera–Mérida Andes–San Sebastián–El Pilar–Trinidad Central Range fault system. Pull-apart basins date from 2.5 Ma at the Cariaco and intra-Gulf of Paria stepovers. Elsewhere the boundary is characterized by transpressional uplift, overwhelmed in some areas (e.g. Gulf of Barcelona; greater Gulf of Paria) by subsidence due to dissolution of inferred, buried, Neocomian rift halite since the Middle Miocene (climate change). The revised timings of events, and the revival of the geosyncline-era concept of Late Cretaceous–Palaeogene orogeny in northern South America, will affect petroleum exploration.
A structuring event of Campanian age in western Venezuela, interpreted from seismic and palaeontological data
Authors: Cooney P. M. , Lorente M. A. 
Published: December 2009

Abstract
A period of structuring, uplift, non-deposition and/or erosion in the Campanian in Western Venezuela, different from the generally known Late Cretaceous event is proposed to explain: (1) a varying time gap (10 to 1 million years) from east to west across the Maracaibo basin between La Luna and Colón formations; (2) a correlating time gap of 11 million years between the Santonian and Upper Campanian sediments in the Barinas basin; (3) structuring at the Top La Luna seismic horizon in the southwestern, west and central parts of the Maracaibo basin which is not reflected in the overlying section; (4) different thickness patterns in the isopach maps for the units underlying the Top La Luna seismic level and the immediately overlying section at least in area of the Colón Unit; (5) an abrupt change in vitrinite reflectance values in the SW of the basin from 0.47–0.60% above to 1.09–1.80% below the top of La Luna Formation; and (6) fission track ages in the range 70–80 Ma in the Circum-Caribbean. The predominant north–south trend of this structuring suggests that it is related to changes on the dynamics of the South American plate boundary during Campanian that may have involved a major igneous and volcanic event registered 70–80 Ma.
The occurrence and timing of high-pressure metamorphism on Margarita Island, Venezuela: a constraint on Caribbean-South America interaction
Authors: Maresch Walter V. , Kluge Rolf , Baumann Albrecht , Pindell James L. , Krückhans-Lueder Gabriela , Stanek Klaus 
Published: December 2009

Abstract

The metamorphic rock sequences exposed on the Island of Margarita, Venezuela, located in the southeastern corner of the Caribbean Plate margin, are composed of a high-pressure/low-temperature (HP/LT) nucleus subducted to at least 50 km depth, now structurally overlain by lower-grade greenschist-facies units lacking any sign of high-pressure subduction-zone metamorphism. The HP/LT nucleus involves protoliths of both oceanic (metabasalts and intimately associated carbonaceous schists of the La Rinconada unit; peridotite massifs) and continental affinity (metapelites, marbles and gneisses of the Juan Griego unit). All HP/LT units were joined together prior to the peak of high-pressure metamorphism, as shown by their matching metamorphic pressure–temperature evolution. The metamorphic grade attained produced barroisite as the regional amphibole. Glaucophane is not known from Margarita. Contrary to a widely propagated assumption, there are no
major
nappe structures
post-dating
HP/LT metamorphism anywhere
within
the high-pressure nucleus of Margarita Island. U–Pb zircon dating of key tonalitic to granitic intrusive rocks provides the following constraints: (1) the Juan Griego unit is heterogeneous and contains Palaeozoic as well as probable Mesozoic protolith; (2) the peak of HP/LT metamorphism, that is maximum subduction, is younger than 116–106 Ma and older than 85 Ma, most probably
c.
100–90 Ma, a time span during which the southeastern Caribbean/South American border was clearly a passive margin. The assembly of Margaritan protoliths and their HP/LT overprint occurred far to the west in northwestern South America, a scenario completely in accord with the details of the Pacific-origin model outlined by Pindell & Kennan. Juxtaposition of the greenschist-facies units occurred after exhumation into mid-crustal levels after
c.
80 Ma.
Evolution of Middle America and the
in situ
Caribbean Plate model
Authors: James Keith H. 
Published: December 2009

Abstract
Regional geological data and global analogues suggest Caribbean Plate geology continues that seen along the margin of eastern North America in a more extensional setting, between the diverging Americas. From west to east there are continental masses with Triassic rifts, proximal continental blocks with kilometres-thick Mesozoic carbonates, more distal areas of Palaeozoic horsts flanked by Triassic–Jurassic dipping wedges of sediments, including salt and overlain by Cretaceous basalts, and most distal areas of serpentinized upper mantle. Plate history began along with the Late Triassic formation of the Central Atlantic Magmatic Province and involved Triassic–Jurassic rifting, Jurassic–Early Cenozoic extension and Oligocene–Recent strike–slip. Great extension promoted volcanism, foundering, eastward growth of the plate by backarc spreading and distribution of continental fragments on the plate interior and along its margins. Hydrocarbons probably are present. Caribbean geology has important implications for understanding of oceanic plateaus, intra-oceanic volcanic arcs, the ‘andesite problem’ and genesis of ‘subduction’ HP/LT metamorphic rocks. The model can be tested by re-examination of existing samples and seismic data and by deep sea drilling.