bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collision-related break-up of a carbonate platform (Eratosthenes Seamount) and mud volcanism on the Mediterranean Ridge: preliminary synthesis and implications of tectonic results of ODP Leg 160 in the Eastern Mediterranean Sea
Authors: Robertson A. H. F. , Emeis K.-C. , Richter C. , Blanc-Valleron M.-M. , Bouloubassi I. , Brumsack H-J. , Cramp A. , Di Stefano G. J. , Flecker R. , Frankel E. , Howell M. W. , Janecek T. R. , Jurado M.-J. , Kemp A. E. S. , Koizumi I. , Kopf A. , Major C. O. , Mart Y. , Pribnow D. F. C. , Rabaute A. , Roberts A. P. , Rullkötter J. , Sakamoto T. , Spezzaferri S. , Staerker T. S. , Stoner J. S. , Whiting B. M. , Woodside J. M. 
Published: September 2007

Abstract
Drilling of the Eratosthenes Seamount south of Cyprus documented incipient collision of the African and Eurasian plates. The oldest sediments recovered, mid?-Cretaceous shallow-water limestones, are overlain by Upper Cretaceous to Lower Oligocene pelagic carbonates, with several hiatuses. Following uplift, a carbonate platform was established in the Miocene; Eratosthenes was then below eustatic sea level during the Messinian desiccation crisis. The platform subsided to bathyal depths during the Lower Pliocene, associated with localized breccia deposition. Further subsidence occurred in Late Pliocene-early Quaternary, coeval with strong surface uplift of southern Cyprus. Subsidence and break-up of Eratosthenes was achieved by a combination of flexural loading and normal faulting. In addition, the Milano and Napoli mud volcanoes were drilled on the northern flank of the Mediterranean Ridge accretionary complex, south of Crete. A mainly extrusive, sedimentary origin is indicated. Multiple debris flows include clasts of sandstone and limestone of at least partly Miocene age. Both mud volcanoes are dated as τ1 Ma old and have been active episodically. Hydrocarbon gas is associated with both mud volcanoes, while methane hydrates (clathrates) exist locally at Milano. The driving force of mud volcanism is overpressuring caused by incipient plate collision. Messinian evaporites may have acted as a localized seal. Material escaped through a zone of backthrusting against rigid Cretan crust to the north.
Application of FMS images in the Ocean Drilling Program: an overview
Authors: Lovell M. A. , Harvey P. K. , Brewer T. S. , Williams C. , Jackson P. D. , Williamson G. 
Published: September 2007

Abstract
Piecing together the evolution of the ocean basins increasingly relies on the integration of data from both recovered core and downhole measurements. This task is often complicated by the limited amount of core recovered by the Ocean Drilling Program (ODP) and the lack of understanding of the downhole data. The availability of downhole electrically based images since ODP Leg 126 in 1989 provides scientists with the visual means of examining the nature of the subsurface, and for tying disparate core to the continuous downhole data. These Formation MicroScanner (FMS) images are unfortunately based on a relatively crude resistivity measurement which provides the interpreter with only an estimate of the resistivity of the rock but, where there are variations in resistivity which correspond to variations in fabric or structure, the measurement response is often sufficient to provide a detailed visual record. Scientists participating in the ODP have explored the use of these images in tackling a wide range of problems from volcanic and sediment stratigraphy to structure and tectonic applications. The determination of core orientation and the mapping of intervals where core recovery is incomplete in particular provide the geologist with a means of carrying out field studies based on borehole and core observations which were previously unthinkable. This paper aims to provide a brief introduction to this subject, and in reviewing some of the principal results to date, illustrates the use of downhole FMS images in the ODP.
A statistical study of hydraulic piston coring, ODP Legs 101–149
Authors: Lee Yir-Der E. , Francis T. J. G. 
Published: September 2007

Abstract

The operational performance of the Advanced Piston Corer over the first 49 legs of the Ocean Drilling Program (ODP) is compared to the physical properties of the cores recovered. Piston coring performance in different sediment types is summarized. The pullout force measured on extracting the piston corer from the sediment is shown to correlate with the shear strength of the sediment cored. Pullout force thus provides a direct measurement of the
in situ
shear strength. Hydraulic piston coring could be used to determine the tensional load-bearing capabilities of sediments where Tension Leg Platforms may be tethered.
Geophysical and geological constraints on the evolution of the Guadalquivir foreland basin, Spain
Authors: Fernàndez M. , Berástegui X. , Puig C. , García-Castellanos D. , Jurado M. J. , Torné M. , Banks C. 
Published: September 2007

Abstract
This paper presents a compilation and reinterpretation of available geophysical and geological data recently acquired for the ENE-WSW Guadalquivir foreland basin, located on the northern margin of the Betic orogen in southern Iberia. The data include seismic reflection and refraction profiles, well logs, gravity, geoid, surface heat-flow data and field observations. The deep structure of the southern Iberian margin is characterized by large variations in crustal thickness and high heat-flow values, which result in a very low lithospheric rigidity for the whole area. Geoid and gravity data show that deformation affected the crust and the lithospheric mantle differently, producing anomalous mass distributions that could act as subsurface loads. Seismic sequence analysis of the basin infill has permitted the re-assessment of the depositional sequential arrangement of the sediments deposited from Late Langhian-Early Serravallian to Messinian. They are arranged in six sequences and do not show any E-W progradational pattern indicating that during this period the acting loads moved essentially in a NNW direction. A careful analysis of the southern border of the basin shows that the ‘so-called olistostromes’ correspond to lateral diapirs of squeezed Triassic evaporites and internally imbricated Miocene wedges. We discuss the results obtained in terms of palaeo-geographic environments, time distribution and nature of acting loads, and constraints for future basin modelling approaches.
Alluvial gravel sedimentation in a contractional growth fold setting, Sant Llorenç de Morunys, southeastern Pyrenees
Authors: Williams Edward A. , Ford Mary , Vergés Jaume , Artoni Andrea 
Published: September 2007

Abstract
New data are presented on the classic growth structure at Sant Llorenç de Morunys (NE Ebro Basin, Spain). During the late Eocene to Oligocene thick alluvial-fan gravel sediments accumulated principally by repetitive sub-aerial mass flow (cohesionless debris flow and fluidal sediment flow) events, with smaller volumes of fan-stream flows. Subaerial, high-viscosity (cohesive) debris flows contributed comparatively small volumes of sediment to the succession. These sediments constructed a complex architecture of conglomeratic and sandstone-bearing lithosomes that were affected by stratal thickening and erosion across a growth fold pair and genetically related internal unconformities, which formed a long-lived thrust-related structure in the immediate footwall of the SE Pyrenean mountain front. Four periods of evolution for the Sant Llorenç growth structure are defined on the basis of distinctive stratigraphical architecture. These describe a gross evolution from onlapping to overlapping growth strata, related to the ultimate demise of growth folding. In detail complex erosional and offlapping events punctuated the growth history, which shows extreme variation parallel to the axis of the structure. Patterns of palaeoflow were highly complex, showing distinct axial and transverse directions relatable to growth fold evolutionary periods. Palaeocurrents are considered to have been deflected and diverted by surficial differential subsidence and areas of relative uplift and erosion generated by fold growth. The complexity of sediment dispersal is compounded by variables intrinsic to alluvial fan environments. The Sant Llorenç de Morunys growth strata provide information on how sediments are reorganized by syndepositionally-growing structures and on the nature of sediment distribution between external fold-and-thrust belts and foreland basins.
Quantified vertical motions and tectonic evolution of the SE Pyrenean foreland basin
Authors: Vergés J. , Marzo M. , Santaeulària T. , Serra-Kiel J. , Burbank D. W. , Muñoz J. A. , Giménez-Montsant J. 
Published: September 2007

Abstract

Local isostatic backstripping analysis is performed across the eastern part of the Ebro foreland basin between the Pyrenees and the Catalan Coastal Ranges. The subsidence analysis is based on two well-dated field-based sections and four oil-wells aligned parallel to the tectonic transport direction of the eastern Pyrenean orogen. The marine infill of the foreland basin is separated into four, third-order, transgressive-regressive depositional cycles. The first and second depositional cycles are located in the Ripoll piggy-back basin and the third and fourth ones are located south of the syn-depositional emergent Vall-fogona thrust. Subsidence curves display a typical convex-up shape with inflection points recording the onset of rapid tectonic subsidence. Inflection points coincide roughly with the base of depositional cycles. Rates of tectonic subsidence are less than 0.1 mm a
−1
in distal parts of the basin and up to 0.53 mm a
−1
in proximal parts during second depositional cycle. Younger depositional cycles show maximum rates of tectonic subsidence of 0.26 mm a
−1
. The locus of subsidence within the basin migrated southward at a rate of
c
. 10 mm a
−1
. This flexural wave crossed the complete Ebro foreland basin in 10–11 Ma. The intraplate Catalan Coastal Ranges at the southeastern margin of the Ebro foreland basin produced an increase of tectonic subsidence rate at 41.5 Ma. Maximum rates of tectonic subsidence coincide with deep-marine infill of the basin, maximum rates of shortening and thrust front advance, and low topographic relief orogenic wedge. Transgressive-regressive depositional cycles can be controlled partly by reductions of available space within the basin during tectonic thickening of the sedimentary pile by layer parallel shortening, folding and thrusting.

Although much less constrained, an approximation of post-thrusting exhumation and isostatic and tectonic uplift, as well as a first determination of possible amounts of eroded material of parts of the Ebro basin illustrate the impact of post-depositional erosion and uplift on the foreland.
Sequential restoration of the external Alpine Digne thrust system, SE France, constrained by kinematic data and synorogenic sediments
Authors: Lickorish W. Henry , Ford Mary 
Published: September 2007

Abstract
The Tertiary foreland basin of the southern Subalpine chains preserves a stratigraphic record of late Alpine deformation, both ahead of the thrust front in the Valensole basin, and in a series of thrust-sheet-top basin remnants. Stratigraphy and growth structures in these basin remnants have been used to identify the location and timing of deformation and hence to constrain the sequential restoration of a cross section through the region.
The thrust belt developed as a single large thrust sheet riding on a weak Triassic evaporite layer. Minor breaching thrusts occur, in particular at Mesozoic normal faults. Kinematic studies of the Digne thrust sheet show a dominantly SW direction of tectonic transport. Where reactivated structures lie at a slightly oblique angle to the transport direction there has been a partitioning of deformation into SW-directed thrusting and a component of dextral strike-slip taken up on minor faults. The total shortening across the fold and thrust belt is 21.5 km, a much lower value than previously estimated but more in line with regional tectonics.
The foreland basin stratigraphy demonstrates that deformation within the Digne sheet occurred in three stages. Firstly, during the late Eocene, Alpine collision in the hinterland caused flexure of the foreland plate to generate a simple broad marine foredeep. Slight detachment above the Triassic evaporites allowed gentle buckling of the floor of the foredeep. Secondly, in the Early to Mid-Oligocene overthrust shear associated with the SW emplacement of the internally derived Embrunais-Ubaye nappes into the foredeep caused substantial deformation in the underlying Digne sheet. A component of flattening strain was associated with overthrust shear beneath the nappes, but ahead of the nappe front gentle, upright folding and thrusting continued. Sedimentation stepped westward, became dominated by continental facies and confined to small thrust sheet top basins (e.g. Barrême). The Mio-Pliocene stage of deformation involved a change from thin-skinned to a thick-skinned out-of-sequence deformation when basement blocks were uplifted on deepseated structures across the region (e.g. dôme de Chateauredon). Shortening associated with the uplift of the main Argentera basement massif at the internal boundary of the external fold and thrust belt was transferred onto the Triassic detachment from below, and transferred forward to reactivate the frontal edge of the Digne sheet, which was thrust out over the Valensole basin.
History and deformation rates of a thrust sheet top basin: the Barrême basin, western Alps, SE France
Authors: Artoni Andrea , Meckel Lawrence D. 
Published: September 2007

Abstract

The geometrical evolution of the 2 km wide Barrême thrust-sheet-top basin has been established over a time interval of 10 Ma. The Barrême basin developed during the late Eocene-Oligocene, during the migration from east to west of the western Alpine orogenic front in SE France. Unlike in other orogenic belts, where foreland basins are often buried and observable only on seismic profiles, the outcrop conditions at Barrême allow the detailed analysis of this basin fragment. The syntectonic sedimentation and growth strata preserved on the east flank of the Barrême basin, on the Clumanc Anticline, are used to restore sequentially a balanced cross-section, thereby constraining the progressive steps of basin development. Numerical ages, obtained by correlating biozones and chronostratigraphy with most recent geochronological calibrations, are assigned to the bases of the mappable growth strata in order to obtain an indication of deformation rates. Shortening rates vary from 0.003 to 0.2 (±0.083) mm a
−1
, while uplift rates vary from 0 to 0.37 mm a
−1
. These rates are comparable to those recorded in recently active mountain belts, and represent a significant refinement of previously published rates for the Barrême basin.
Thin-skinned inversion tectonics at oblique basin margins: example of the western Vercors and Chartreuse Subalpine massifs (SE France)
Authors: Philippe Yann , Deville Eric , Mascle Alain 
Published: September 2007

Abstract
The western Vercors and Chartreuse Subalpine fold-and-thrust belts form part of the western Alpine foreland that wa sinvolved in Neogene compressive tectonics. The deformation front of the two massifs is superimposed on the western margin of the Mesozoic Southeast Basin, which was inverted in the Late Miocene. Obliquity between this NE-SW-directed basin margin and the WNW-ESE Alpine tectonic transport resulted in the development of en-échelon folds and thrusts at the leading edge of the massifs. The gradual change of the tectonic style from the Chartreuse to the southern Vercors belts denotes that the initial configuration of the basin as well as the rheological properties of the basal detachment layer strongly influenced the geometry and the kinematic evolution of the two fold belts. This paper presents the geometry of the inverted western Tethyan palaeomargin through a series of balanced cross-sections and attempts to evaluate the possible boundary conditions that controlled the development of the western Chartreuse and Vercors massifs and the lateral variations of the tectonic style in the study area. Results of an analogue modelling experiment simulating a thin-skinned inversion of an oblique platform-basin transition zone are compared with those of the field study and used to discuss the role of the palaeogeographic inheritance on both the initiation and orientation of thrust faults in décollement tectonics.
Tectono-stratigraphy and hydrocarbons in the Molasse Foredeep of Salzburg, Upper and Lower Austria
Authors: Wagner Ludwig R. 
Published: September 2007

Abstract
The evolution of the sedimentary record and the tectonic setting of the Molasse Basin at the margin of the European platform from the Bavarian border across Salzburg, Upper and Lower Austria to the border of the Tschech Republic provides the possibility of unravelling the history of the Alpine - Carpathian Foredeep. The marine ingressions and the sedimentary processes reflect the dynamic process of the plate tectonics and the Alpine Orogeny. At present the outcrop of the passive margin of the Bohemian Massif and the northern edge of the active Molasse thrust front approach each other within a distance of a few kilometres. The basement is broken into several fault blocks. Tectonic activities within the thrust sheets as well as lateral movements of the basement along the flanks of the craton are ongoing.
The hydrocarbon generation and trapping is based on the interaction of synsedimentary tectonism, erosion and deposition.
This study is based on surface and subsurface data acquired by Rohöl Aufsuchungs AG (RAG) and Österreichische Mineralöl Verwaltungs AG (OMV) during its exploration in Salzburg, Upper and Lower Austria.
Flexure and ‘unflexure’ of the North Alpine German-Austrian Molasse Basin: constraints from forward tectonic modelling
Authors: Andeweg B. , Cloetingh S. 
Published: September 2007

Abstract
We present the results of forward modelling of the Northern Alpine German-Austrian Molasse Basin, which forms part of the Northern Alpine Foreland Basin (NAFB) extending from Lake Geneva in the west to Lower Austria in the east. The observed deflection of the European plate under the NAFB has been modelled along five profiles perpendicular to the basin axis. Models treating the deflection of the NAFB as a flexural response to loading only, require a set of loading parameters (bending moment, vertical force) which would imply bending stresses exceeding the strength of the subsiding plate. Moreover, this approach would not take into account the significant post-Molasse uplift experienced by the Alpine chain and its northern foreland basins. We modelled the deflection as the response to two distinct processes: (1) flexure of an elastic plate with lateral variations (EET-values of 7–26 km from east to west) loaded with surface and limited subsurface loads and (2) the Late Cenozoic (post-molasse) phase of ‘unflexing’, significant uplift observed in the Alps and its northern foreland. Our study provides a first attempt to separate these two processes in order to model the deflection by an elastic plate-model, adopting flexural parameters that will not exceed the strength of the lithosphere.
A primer on the geological occurrence of gas hydrate
Authors: Kvenvolden K. A. 
Published: September 2007

Abstract

Natural gas hydrates occur world-wide in polar regions, usually associated with onshore and offshore permafrost, and in sediment of outer continental and insular margins. The total amount of methane in gas hydrates probably exceeds 10
19
g of methane carbon. Three aspects of gas hydrates are important: their fossil fuel resource potential; their role as a submarine geohazard; and their effects on global climate change. Because gas hydrates represent a large amount of methane within 2000 m of the Earth’s surface, they are considered to be an unconventional, unproven source of fossil fuel. Because gas hydrates are metastable, changes of pressure and temperature affect their stability. Destabilized gas hydrates beneath the sea floor lead to geological hazards such as submarine slumps and slides, examples of which are found world-wide. Destabilized gas hydrates may also affect climate through the release of methane, a ‘greenhouse’ gas, which may enhance global warming and be a factor in global climate change.
Physical/chemical properties of gas hydrates and application to world margin stability and climatic change
Authors: Sloan E. D. 
Published: September 2007

Abstract
The major points in this paper concern: (a) physical and chemical properties and (b) applications of those properties. Three questions are addressed: What are hydrates? What is our knowledge about their thermodynamic and kinetic properties? What are the applications to the environment and climate stability?
The physical and chemical characteristics of hydrates are approximated by three heuristics: (1) physical properties approximate those of ice, (2) phase equilibrium characteristics are set by the size ratio of guest within host cages, and (3) thermal properties are set by hydrogenbonded crystals with cavity size ratios. Knowledge of hydrate kinetics is substantially lacking, but it appears that formation kinetics derive from aggregation of water clusters at interfaces. A significant future challenge is to characterize hydrates directly (through NMR, Raman, diffraction, etc.) for both thermodynamics and kinetics.
Hydrocarbons in natural hydrates represent twice the amount of all combined fossil fuels. Most recovered samples have been small, dispersed (even dissociated) particles with isolated examples of massive hydrates. Hydrates probably will not contribute significant methane to the atmosphere in the near future. Ocean hydrates and air hydrates from Antarctic ice are indicators of ancient climatic changes.
Gas hydrate accumulation in deep-water marine sediments
Authors: Ginsburg G. D. 
Published: September 2007

Abstract
The accumulation of gas hydrates largely depends on the spatial variability of gas solubility in pore waters. Within the submarine gas hydrate stability zone the solubility of methane in water significantly decreases towards the sea floor in response to temperature lowering. Gas hydrates can precipitate from methane-saturated water seeping up. They also accumulate from diffusing gas and segregated pore water within diffusion aureoles associated with the ascending fluid flows and with the zones where biochemical methane is generated at high rates. Hydrates more readily form in sediments where pore waters are relatively fresh and pores are rather large. The thermobaric gas hydrate stability zone is a geochemical barrier for hydrocarbon gases migrating from sediments into the sea water. However, the rising gas is not completely preserved in the hydrate.
The occurrence of gas hydrates in Eastern Mediterranean mud dome structures as indicated by pore-water composition
Authors: De Lange G. J. , Brumsack H.-J. 
Published: September 2007

Abstract

During ODP Leg 160 to the Eastern Mediterranean, two mud dome structures have been sampled. The massive presence of gas hydrates at relatively shallow depths in the sediment of one of these, Milano Dome, contrasts to that of the other, Napoli Dome, where gas hydrates are unlikely to be present at depths greater than 1 m below the sea floor (mbsf). Some observations from very shallow pore-waters at Napoli Dome, however, suggest that some gas hydrates must be present above 1 mbsf. In the case of Milano Dome, it is likely that a massive cap of gas hydrates is overlying natural gas that cannot escape due to this cap and its shape. In this report, some of the mud dome pore-water results of Ocean Drilling Program Leg 160 to the Eastern Mediterranean are discussed in relation to the inferred presence of gas hydrates. In addition, the total quantity of methane, including gas hydrates and ‘free gas’, has been estimated for Milano Dome (∼5 × 10
9
m
3
CH
4
) and for the Eastern Mediterranean Ridge mud dome structures (∼1 × 10
14
m
3
CH
4
).