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Now showing items 8-21 of 21

Fault displacement rates on a range of timescales

Mouslopoulou, Vasiliki ; Walsh, John J. ; Nicol, Andrew (Elsevier, 2009-02-25)

Displacements on tectonic faults primarily accrue during earthquakes at rates that vary through time. To examine the processes that underlie the temporal changes in fault displacement rates we analyse displacements and ...
A first evaluation of the spatial gradients in δ18Orecorded by European Holocene speleothems

McDermott, Frank ; Atkinson, Tim ; Fairchild, Ian J. ; Baldini, Lisa M. ; Mattey, David P. (Elsevier, 2011-12)

Oxygen isotope data for well dated Holocene speleothems from Europe have been compiled for the first time. The data were analysed at 1 ka time slices through the Holocene by taking averages of 50 year duration. After filtering ...
Geometrical analysis of the refraction and segmentation of normal faults in periodically layered sequences

Schöpfer, Martin P. J. ; Childs, Conrad ; Walsh, John J. ; Manzocchi, Tom ; Koyi, Hemin A. (Elsevier, 2007-02)

Normal faults contained in multilayers are often characterised by dip refraction which is generally attributed to differences in the mechanical properties of the layers, sometimes leading to different modes of fracture. ...
Geometric and kinematic controls on the internal structure of a large normal fault in massive limestones : the Maghlaq Fault, Malta

Bonson, Chris G. ; Childs, Conrad ; Walsh, John J. ; Schöpfer, Martin P. J. ; Carboni, Vincent (Elsevier, 2007-02)

The Maghlaq Fault is a large, left-stepping normal fault (displacement >210 m) cutting the Oligo-Miocene pre- to syn-rift carbonates of SW Malta. Two principal slip zones separate the deformed rocks of the fault zone from ...
The impact of porosity and crack density on the elasticity, strength and friction of cohesive granular materials : insights from DEM modelling

Schöpfer, Martin P. J. ; Abe, Steffen ; Childs, Conrad ; Walsh, John J. (Elsevier, 2009-02)

Empirical rock properties and continuum mechanics provide a basis for defining relationships between a variety of mechanical properties, such as strength, friction angle, Young’s modulus, Poisson’s ratio, on the one hand ...
K-feldspar sand-grain provenance in the Triassic, west of Shetland : distinguishing first-cycle and recycled sediment sources?

Tyrrell, Shane ; Leleu, Sophie ; Souders, A. Kate ; Haughton, P. D. W. ; Daly, J. Stephen (John Wiley and Sons, 2009-11)

Sandstone provenance studies can help constrain palaeogeographic reconstructions and ancient drainage system scales and pathways. However, these insights can be obscured by difficulties in geochemically distinguishing or ...
Large-scale, linked drainage systems in the NW European Triassic: insights from the Pb isotopic composition of detrital K-feldspar

Tyrrell, Shane ; Souders, A. Kate ; Daly, J. Stephen ; Shannon, Patrick M. ; Haughton, P. D. W. (The Geological Society, 2012-05)

Pb isotopic data from K-feldspars in Middle Triassic (Anisian) sandstones in the Wessex Basin, onshore southwest UK, and the East Irish Sea Basin, some to the north, show that the same grain populations are present. This ...
A late-Holocene climate record in stalagmites from Modrič Cave (Croatia)

Rudzka, Dominika ; McDermott, Frank ; Suric, Masa (Wiley, 2012)

Few terrestrial Holocene climate records exist from Southeastern Europe despite its important geographic position as a transitional climatic zone between the Mediterranean and mainland continental Europe. In this study we ...
Localisation of normal faults in multilayer sequences

Schöpfer, Martin P. J. ; Childs, Conrad ; Walsh, John J. (Elsevier, 2006-05)

Existing conceptual growth models for faults in layered sequences suggest that faults first localise in strong, and brittle, layers and are later linked in weak, and ductile, layers. We use the Discrete Element Method (DEM) ...
Reconciliation of contrasting theories for fracture spacing in layered rocks

Schöpfer, Martin P. J. ; Arslan, Arzu ; Walsh, John J. ; Childs, Conrad (Elsevier, 2011-04)

Natural and man-made brittle layers embedded in a weaker matrix and subjected to layer-parallel extension typically develop an array of opening-mode fractures with a remarkably regular spacing. This spacing often scales ...
Sedimentology, sandstone provenance and palaeodrainage on the eastern Rockall Basin margin : evidence from the Pb isotopic composition of detrital K-feldspar

Tyrrell, Shane ; Souders, A. Kate ; Haughton, P. D. W. ; Daly, J. Stephen ; Shannon, Patrick M. (The Geological Society of London, 2010)

The Rockall Basin, west of Ireland, is a frontier area for hydrocarbon exploration but currently the age and location of sand fairways through the basin are poorly known. A recently developed provenance approach based on ...
Source separation on seismic data : application in a geophysical setting

Moni, Aishwarya ; Bean, Christopher J. ; Lokmer, Ivan ; Rickard, Scott (Institute of Electrical and Electronic Engineers, 2012-05)

This article gives a brief description of the Degenerate Unmixing Estimation Technique (DUET) and applies it in a geophysical setting. Source separation has not been fully addressed by geophysicists and is a crucial first ...
Static and dynamic connectivity in bed-scale models of faulted and unfaulted turbidites

Manzocchi, Tom ; Walsh, John J. ; Tomasso, Mark ; Strand, Julian ; Childs, Conrad ; Haughton, P. D. W. (Geological Society, London, 2007)

A range of unfaulted and faulted bed-scale models with sheet-like bed geometries have been built and analysed in terms of static bed connectivity and fractional permeability assuming permeable sands and impermeable shales. ...
Zn, Fe and S isotope fractionation in a large hydrothermal system

Gagnevin, Damien ; Boyce, Adrian ; Barrie, Craig ; Menuge, Julian ; Blakeman, Robert (Elsevier, 2012-07-01)

The genesis of hydrothermal ore deposits is of crucial economic importance. This study investigates the extent, causes and consequences of zinc and iron isotope fractionation in a large hydrothermal system at the world-class ...