2012. "Otway Basin", Atlas of Australian and New Zealand Hydrocarbon Seals: Worldwide Analogs for Cap Rocks and Intraformational Barriers in Clastic Depositional Settings, Richard (Ric) Daniel, John Kaldi
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The Otway Basin is one of several passive margin-type basins found along the southern margin of Australia. It formed as a result of the Gondwana rifting during the Jurassic and Cretaceous that ultimately led to the separation of Antarctica and Australia (Stagg et al., 1990). Early Mesozoic rifting evolution in the Otway Basin, and especially in the western Otway Basin, was characterized by the for-mation of a series of east-west trending, half grabens, which were controlled by steep, northward dipping, extensional faults (Hill, 1995) (Figure 19). Onset of the major rifting phase in the Late Jurassic led to the development of the Robe, Colac, and Gellibrand troughs. The Penola Trough and most of the early half-grabens in the western part of the Victorian Otway Basin may have formed as oblique or transtensional rift segments. The sediments of the Otway Group, which consists of the Casterton, Pretty Hill, Laira, and Eumeralla formations (see examples from South Australia, Figure 19), were deposited in a range of syn-tectonic sedimentary environments (Kopsen and Scholefield, 1990).