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Browsing by Author "Walsh, John J."

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2D distinct element modeling of the structure and growth of normal faults in multilayer sequences : 1. Model calibration, boundary conditions, and selected results

Schöpfer, Martin P. J. ; Childs, Conrad ; Walsh, John J. (American Geophysical Union, 2007)

The distinct element method is used for modeling the growth of normal faults in layered sequences. The models consist of circular particles that can be bonded together with breakable cement. Size effects of the model ...
2D distinct element modeling of the structure and growth of normal faults in multilayer sequences : 2. Impact of confining pressure and strength contrast on fault zone growth and geometry

Schöpfer, Martin P. J. ; Childs, Conrad ; Walsh, John J. (American Geophysical Union, 2007)

The growth of normal faults in periodically layered sequences with varying strength contrast and at varying confining pressure is modeled using the Distinct Element Method. The normal faulting models are comprised of strong ...
Calibrating fault seal using a hydrocarbon migration model of the Oseberg Syd area, Viking Graben

Childs, Conrad ; Sylta, Oyvind ; Moriya, S. ; Morewood, Nigel ; Manzocchi, Tom ; Walsh, John J. ; Hermanssen, D. (Elsevier, 2009-06)

It is widely acknowledged that fault rock capillary properties are important in controlling the distribution of hydrocarbons in sedimentary basins, and methods exist for predicting the capillary seal capacity of prospect ...
Definition of a fault permeability predictor from outcrop studies of a faulted turbidite sequence, Taranaki, New Zealand

Childs, Conrad ; Walsh, John J. ; Manzocchi, Tom ; Strand, Julian ; Nicol, Andrew ; Tomasso, Mark ; Schöpfer, Martin P. J. ; Aplin, Andrew C. (Geological Society, London, 2007)

Post-depositional normal faults within the turbidite sequence of the Late Miocene Mount Messenger Formation of the Taranaki basin, New Zealand are characterised by granulation and cataclasis of sands and by the smearing ...
Earthquake histories and Holocene acceleration of fault displacement rates

Nicol, Andrew ; Walsh, John J. ; Mouslopoulou, Vasiliki ; Villamor, Pilar (Geological Society of America, 2009-10)

Displacement rates for normal and reverse faults (N = 57) are generally higher when averaged for the Holocene (~10 ka) than for the late Quaternary (~300 ka) and longer time scales. Holocene acceleration of displacement ...
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 ...
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 ...
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 ...
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. ...