The Geometry and Growth of Normal Faults
The relationship between normal drag, relay ramp aspect ratio and fault zone structure
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Published:January 01, 2017
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CiteCitation
C. Childs, T. Manzocchi, A. Nicol, J.J. Walsh, A.M. Soden, J.C. Conneally, E. Delogkos, 2017. "The relationship between normal drag, relay ramp aspect ratio and fault zone structure", The Geometry and Growth of Normal Faults, C. Childs, R. E. Holdsworth, C. A.-L. Jackson, T. Manzocchi, J. J. Walsh, G. Yielding
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Abstract:
The boundaries between pairs of adjacent fault segments within normal fault arrays define a spectrum of structures, from relay ramps where the length of overlap between the fault segments is much larger than the separation, through low aspect ratio (overlap/separation) relay ramps and ultimately to underlapping fault segments. Where fault segments underlap, transfer of displacement between them is accommodated by a connecting monocline. When displacement increases and a through-going fault forms, relay ramps are preserved as fault-bounded zones of elevated bed dip and monoclines are preserved as areas of normal drag. Therefore, the orientation and magnitude of bed dips within and adjacent to a fault zone, and the numbers of segments seen on a cross-section through it, depend largely on the aspect ratios of relay ramps in the initial fault array. The aspect ratio of relay ramps varies between different fault systems. An analysis of the geometry of 512 relay ramps from 13 different fault systems suggests that the main controls on aspect ratio are the strength of the sequence at the time of faulting and the underlying structure.
- accommodation zones
- Australasia
- bedding faults
- controls
- cross sections
- dip
- displacements
- drag folds
- Europe
- fault zones
- faults
- folds
- geometry
- geophysical profiles
- Grand County Utah
- Greece
- Greek Macedonia
- Macedonia
- Moab Utah
- monoclines
- New Mexico
- New Zealand
- normal faults
- North Island
- orientation
- ramps
- segmentation
- seismic profiles
- Southern Europe
- spatial distribution
- spatial variations
- stiffness
- strength
- structural analysis
- structural geology
- systems
- three-dimensional models
- United States
- Utah
- weak rocks
- Yellow Cat Flat
- Sand Hills Fault
- aspect ratio
- relay ramps
- relay zones
- Ptolemais Macedonia