Impacts of Neogene-Recent compressional deformation and uplift on hydrocarbon prospectivity of the passive southern Australian margin

Cenozoic deformation in the Otway Basin, southern Australian margin: implications for the origin and nature of post‐breakup compression at rifted margins

“…Along this margin, compressional structures have been most commonly identified within the post‐rift Cenozoic successions of the Otway, Gippsland and Bass basins (Hill et al ., ; Perincek & Cockshell, ; Dickinson et al ., ; Hillis et al ., ), and many significant oil and gas producing fields in these basins are hosted within Cenozoic anticlines (Bernecker et al ., ; Holford et al ., ). Similar Cenozoic anticlines occur within the Torquay sub‐basin (Holford et al ., ) but drilling has shown that they do not contain significant quantities of hydrocarbons (Trupp et al ., ), implying that the relative timing of compressional deformation with respect to hydrocarbon generation and charge is a key factor in defining prospectivity along the margin (Duddy, ; Holford et al ., ).…”

Quantifying Neogene plate-boundary controlled uplift and deformation of the southern Australian margin

“…Modified from Holford et al (2011a). Sub-basin such as the Nerita Anticline (Figs 4 & 5; Holford et al 2010Holford et al , 2011a. Similar Late Neogene exhumation magnitudes are inferred from apatite fission track data from the onshore Anglesea-1 well in the Torquay Sub-basin (c. 0.85 km; Green et al 2004) and from the Olangolah-1 well that was drilled into the Otway Ranges (c. 1 km; Cooper & Hill 1997;Fig.…”

“…Apatite fission-track data from the Anglesea-1 and Nerita-1 wells indicate that cooling and exhumation of Miocene and older rocks in the eastern Otway Basin commenced between 10 and 5 Ma ( Fig. 3c; Green et al 2004;Holford et al 2010), which compares well with the age of the Late Miocene -Early Pliocene unconformity (Fig. 3b).…”

“…Both the regional Late Miocene -Early Pliocene unconformity and some of the Neogene compressional structures in the Otway Basin are locally associated with substantial exhumation. The timing, magnitude and distribution of this exhumation have been independently constrained by analysing the thermal histories of Miocene and older sediments using apatite fission-track data from hydrocarbon exploration wells (Figs 4 & 5;Cooper & Hill 1997;Green et al 2004;Holford et al 2010Holford et al , 2011aunpublished Geotrack International reports). Apatite fission-track data from the Anglesea-1 and Nerita-1 wells indicate that cooling and exhumation of Miocene and older rocks in the eastern Otway Basin commenced between 10 and 5 Ma ( Fig.…”

Quantifying Cretaceous–Cenozoic exhumation in the Otway Basin, southeastern Australia, using sonic transit time data: Implications for conventional and unconventional hydrocarbon prospectivity

“…Clearly, in these areas, significant burial during the Late Cretaceous to Cenozoic (as much as >1700 m [∼5580 ft]) has been sufficient to overcome the effects of any earlier mid-Cretaceous exhumation or possible elevated heat flow ( Figure 16D). Although evidence for fault reactivation and inversion in the Port Campbell Embayment and Shipwreck trough has existed since the late Miocene (e.g., Sandiford, 2003;Holford et al, 2010), accompanying exhumation has been minor and insufficient to switch off hydrocarbon generation (Duddy, 1997;Holford et al, 2010), such that hydrocarbon charge rates may be exceeding leakage rates.…”