Results 271 to 280 of about 62,824 (310)

Fault displacement gradients on normal faults and associated deformation

AAPG Bulletin, 2014
ABSTRACT Faults are important components of hydrocarbon and other reservoirs; they can affect trapping of fluids, flow pathways, compartmentalization, production rates, and through these, production strategies and economic outcomes. Displacement gradients on faults are associated with off-fault deformation, which can be manifest as ...
Alan P. Morris, Ronald N. McGinnis, DavidA. Ferrill   +2 more
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On the rotation and frictional lock-up of normal faults: Explaining the dip distribution of normal fault earthquakes and resolving the low-angle normal fault paradox

Tectonophysics, 2020
Abstract Classical rock mechanics predicts that normal faults should form at 60–65°, rotating to 30–40° before locking, so widespread slip at around 20° is considered paradoxical. Furthermore, the dip distribution of normal fault earthquakes has a distinct, unexplained peak at ~45°.
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Crossing Conjugate Normal Faults

AAPG Bulletin, 2000
Abstract Normal faults commonly develop in two oppositely dipping sets having dihedral angles of around 60°, collectively referred to as conjugate normalfaults. Conjugate normal faults form at a range of scales from cm to km. Where conjugate normal faults cross each other, the faults are commonly interpreted to accommodate extension ...
David A. Ferrill, Alan P. Morris, John A. Stamatakos, Darrell W. Sims   +3 more
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The Mahelma Fault: An Inverted Normal Fault Of Mitidja Basin?

Proceedings, 2017
Summary This presentation reviews the new data; from both geophysical and geological investigations, carried out through the Sidi-Abdellah microzoning project. As a whole, data indicate that the Mahelma Fault would be an earlier normal fault of the Mitidja basin.
H. Moulouel, A. Bouchelouh, R. Bensalem, E. Oubaiche, Y. Tebbouche, D. Ait-Benamar, D. Machane   +6 more
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Displacement rates of normal faults

Nature, 1997
Previous estimates of displacement rates on individual faults have been limited to neotectonic faults and averaged over time intervals of about 200 kyr or less1,2,3,4,5. These estimates have been highly variable, which has led to a belief that longer-term displacement rates on individual faults are likely to be variable as well.
A. Nicol‡, J. J. Walsh, J. Watterson, J. R. Underhill   +3 more
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Anticlustering of small normal faults around larger faults

Geology, 1997
The Solite quarry in the Mesozoic Danville rift basin contains normal faults that conform to two spatial and size distributions. Larger master normal faults (20 cm < length [ L] < 200 cm) are not numerous and have spanned the mechanical layer. The other faults are numerous, small (~0.1 cm < L < 20 cm), and exhibit anticlustering with respect to the ...
Rolf V. Ackermann, Roy W. Schlische
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Myths about normal faulting

Geological Society, London, Special Publications, 2016
Abstract Analyses of normal faults in mechanically layered strata reveal that material properties of rock layers strongly influence fault nucleation points, fault extent (trace length), failure mode (shear v. hybrid), fault geometry (e.g.
D. A. Ferrill, A. P. Morris, R. N. McGinnis, K. J. Smart   +3 more
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Mechanical stratigraphy and normal faulting

Journal of Structural Geology, 2017
Abstract Mechanical stratigraphy encompasses the mechanical properties, thicknesses, and interface properties of rock units. Although mechanical stratigraphy often relates directly to lithostratigraphy, lithologic description alone does not adequately describe mechanical behavior. Analyses of normal faults with displacements of millimeters to 10's of
David A. Ferrill, Alan P. Morris, Ronald N. McGinnis, Kevin J. Smart, Sarah S. Wigginton, Nicola J. Hill   +5 more
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Normal Fault Structures and Others

AAPG Bulletin, 1946
ABSTRACT This paper emphasizes the importance of shearing as a kind of deformation which is often confused with folding. It presents a type of normal faulting as a mountain-making effect due to uplift against gravity. The structure of the Colorado plateaus is taken as the type. Basin-range faulting is regarded as closely similar.
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flexural rotation of normal faults

Tectonics, 1988
A conceptual model is proposed for the generation of low‐angle normal faults in Metamorphic Core Complexes. The model is based on three assumptions: (1) the isostatic response to normal fault motion is of regional extent; (2) when a fault segment is significantly rotated from the optimum angle of slip, relative to the crustal stress field, it is ...
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