Publication Name: The North West Shelf Australia
Authors: S.C. Eriyagama, L.B. Collins and R.M. Hocking
Date Published: July 1988
Number of Pages: 26
Reference Type: Book Section
Abstract:
Deposition of Barrow Group sediments took place in the rift-related Barrow Sub-basin during the Neocomian. The delta progradation was limited on the east by a series of down-to-the-basin normal faults with a NNE-SSW orientation. Fault-controlled basin architecture has influenced Barrow deposition, and younger wrench movements have modified the original structural trends in some parts of the basin. In spite of the diachronous nature ofthe deltaic sedimentary units, lithostratigraphic subdivisions of regional validity, correlatable in the subsurface, have been established. Existing Barrow Group subdivisions into Flacourt and Malouet Formations can be maintained. The Flag Sandstone is a deep water facies of the Barrow Group in the north, and is a lateral equivalent of the Flacourt Formation in the east-central area. In the central part of the Barrow delta-basin complex, both Flacourt and Malouet Formations are present. Regional isopach maps in conjunction with the major structural elements illustrate the structural evolution during Barrow Group sedimentation. Wireline log-lithology correlations together with seismic data reveal regional stratigraphic variations within the Flacourt Formation, and these have exploration significance.Potential play types identified in the study area include en-echelon anticlinal features associated with minor wrench movements, closures in tilted fault blocks and rollover anticlines associated with listric faulting, Barrow Group pinchouts, possible rollover anticlines associated with antithetic faults, and onlap plays related to an intra-Barrow unconformity.