Biogeographical observations on the Cretaceous biota of Australasia
Henderson, R.A., Crampton, J.S., Dettmann, M.E., Douglas, J.G., Haig, D., Shafik, S., Stilwell, J.D., and Thulborn, R.A. (2000) Biogeographical observations on the Cretaceous biota of Australasia. Memoirs of the Association of Australian Palaeontologists, 23 . pp. 355-404.
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[Extract] The Cretaceous System is well represented in Australasia (Fig. 1). The generation of new seafloor to the west, south, and east of continental Australia, associated with the Cretaceous fragmentation of Gondwana (see Veevers et al. 1991), led to the development of extensive passive margin sedimentary systems. Fragmentation and the generation of new seafloor had commenced by the mid-Jurassic for northwestern Australia (Fig. 2). Although the history of oceanic crust adjacent to much of northern Australia is unknown, the entire sector of continental borderland stretching from North West Cape to Melville Island is considered as a single morphotectonic tract. The North West Shelf and the associated passive margin assemblage is referred to as the Westralian Superbasin (see Bradshaw et al. 1988).
The Cretaceous System comprises a major part of the Westralian Superbasin. Neocomian strata are generally of paralic aspect but some contain nannoplankton indicative of open-marine conditions (Shafik 1994). A widely developed Aptian transgression brought open marine mudstones and siltstones to much ofthe superbasin in late Early Cretaceous time. By the middle of the Late Cretaceous, carbonate sedimentation became dominant in all but the eastern sector of the superbasin. In comparison to the offshore representation of the Cretaceous System, its onshore development is minor. At its western extremity, the superbasin incorporates onshore sequences of the Carnarvon Basin which are essentally continuous from the Aptian to the Maastrichtian (Hocking et al. 1987). To the east, it incorporates the Money Shoals Platform where onshore sequences range from Aptian to Turonian in age (Henderson 1998). Remnants of an ephemeral blanket of upper Lower Cretaceous strata has been widely recognised for the continental borderland to the Westralian Basin, indicating that the Aptian-Albian transgression was widely developed (Frakes et al. 1987).
|Item Type:||Article (Refereed Research - C1)|
|FoR Codes:||04 EARTH SCIENCES > 0403 Geology > 040308 Palaeontology (incl Palynology) @ 100%|
|SEO Codes:||97 EXPANDING KNOWLEDGE > 970104 Expanding Knowledge in the Earth Sciences @ 100%|
|Deposited On:||15 Dec 2010 08:56|
|Last Modified:||12 Feb 2011 03:56|
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