About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
AAPG Bulletin
Abstract
AAPG Bulletin, V.
DOI: 10.1306/01211917256
Fault
surface development and
fault
rock juxtaposition along deformation band clusters in porous sandstones series
![Previous Hit](/data/images/arrow_left.gif)
![Next Hit](/data/images/arrow_right.gif)
![Previous Hit](/data/images/arrow_left.gif)
![Next Hit](/data/images/arrow_right.gif)
Sven Philit,1 Roger Soliva,2 Gregory Ballas,3 Alexandre Chemenda,4 and Raymi Castilla5
1Géosciences Montpellier, Unité Mixte de Recherche (UMR) 5243, Université de Montpellier–Centre National de la Recherche Scientifique (CNRS), Montpellier, France; [email protected]
2Géosciences Montpellier, UMR 5243, Université de Montpellier–CNRS, Montpellier, France; [email protected]
3Géosciences Montpellier, UMR 5243, Universite de Montpellier–CNRS, Montpellier, France; [email protected]
4Géoazur, Université de Nice-Sophia Antipolis, Valbonne, France; [email protected]
5Research and Development Frontier Exploration, Total, Pau, France; [email protected]
ABSTRACT
Our field study examines two sites revealing the processes responsible for fault
surface development and
fault
rock juxtaposition along normal faults in porous-sandstone–dominated formations. At the first site, we show that a cluster of cataclastic deformation bands made in an initially poorly consolidated sandstone localizes overprinting of a
fault
slip surface and brecciation during a subsequent tectonic episode, after a significant diagenesis of the formation induced by burial. Because the permeability of the clusters ranges between 6 × 100 and less than 5 × 10−1 md and because the breccia was highly dilatant, we deduce that the
fault
behaved as a baffle for cross-
fault
fluid flow at an early age of the formation and as a conduit after significant diagenetic evolution and subsequent
fault
surface development. At the second site, we show that the presence of clay-rich layers as thin as 80 cm (31 in.) are responsible for the initiation of a major
fault
slip surface in the underlying and overlying sandstone. The propagation of the
fault
prevents further cataclastic deformation and cluster development in these sandstones.
Fault
displacement juxtaposes
fault
surfaces, clusters of cataclastic deformation bands, clay-rich gouges, and different sedimentary units. Because both
fault
rocks have low permeability, their spatial juxtaposition provides a continuous baffle for cross-
fault
fluid flow. Our study shows that
fault
surface localization is related to an increase in the contrast of mechanical behavior between the cluster and the adjacent material (diagenetic hardening of the cluster or softening of the clay-rich gouge). Lithological contrasts and diagenesis are favorable conditions for localizing faulting and
fault
rock juxtaposition, allowing significant three-dimensional anisotropy of permeability during and/or after deformation. These processes must, therefore, be considered for
fault
-seal analyses in sandstone reservoirs.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |
AAPG Member?
Please login with your Member username and password.
Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].