000 03096nab a2200193 4500
005 20260520000236.0
008 260224s2010 xxu
245 0 0 _aExtensional fault segmentation and linkages, Bonaparte Basin, outer North West Shelf, Australia
260 _a
_b
_cjul. 2010
270 _a13/08/2010 ; 13/08/2010
300 _a34 p. ; 977-1010
520 _aTranscripción del resumen del autor. A detailed structural analysis of the Zone of Cooperation A-2 (ZOCA-2) three-dimensional (3-D) seismic survey on the outer northwestern edge of the Sahul Platform, northern Bonaparte Basin, outer North West Shelf, Australia, has identified three major populations of extensional faults. From oldest to youngest, these are (1) Jurassic north-south–trending extensional synrift faults, (2) Jurassic–Cretaceous east-west– to east-northeast–west-southwest–trending extensional faults, and (3) Neogene to present-day northeast-southwest–striking, right-stepping en-echelon faults. Seismic attribute analyses combined with fault-displacement analyses have illustrated the initial segmentation of all of the fault systems and characterized both the horizontal and vertical linkages formed by soft-linkage relay structures. The strongly segmented Neogene to present-day northeast-southwest–striking faults are interpreted to be a result of Neogene reactivation of underlying zones of weakness generated by preexisting east-northeast–trending Jurassic to Early Cretaceous faults. The Neogene to present-day northwest-southeast–directed extension was oblique to the underlying zones of weakness and thus formed characteristic strongly segmented en-echelon fault arrays. The Jurassic to Early Cretaceous extensional faults together with the overlying northeast-southwest–striking Neogene to present-day fault systems form a pseudoconjugate fault system separated by a Cretaceous sequence that acted as a decoupling horizon. Within this Cretaceous interval, which is characterized by polygonal fault systems, vertically segmented, isolated, and overlapping extensional fault arrays form a zone of soft linkage between the underlying Jurassic to Early Cretaceous rift faults and the overlying Neogene to present-day fault systems. This study shows that extension oblique to preexisting deeper fault systems produces en-echelon segmented extensional faults in the overlying sequences. Such en-echelon segmentation does not indicate major strike-slip deformation. The results of this research have implications for understanding the distribution, segmentation, linkages, and ages of extensional faults in many other rift basins as well as for the northern Bonaparte Basin. In addition, the complex 3-D linkage patterns shown in this study have significant implications for understanding trap geometries and fault-seal characteristics in other extensionally faulted basins.
581 _a7
773 0 _tAAPG Bulletin
_g94
942 _cARTICULO
100 1 _aFrankowicz, E.
_946394
100 1 _aMcClay, K.R.
_919087
999 _c175992
_d175992