Abstract The New Guinea Limestone Group was deposited across much of New Guinea, including the Indonesian provinces of West Papua and Papua, as part of a widespread shallow-water carbonate platform during the Paleogene and Neogene. This platform was drowned beneath deeper-water strata from the Middle to Late Miocene. Review of biostratigraphic and seismic data from the Aru Basin, offshore New Guinea, reveals a drowning succession c. 600 m thick deposited during a drowning event that lasted around 4 Ma. The objective of this study was to create a well-to-seismic tie from a single well in the study area using biostratigraphic, seismic and log data. The well-to-seismic tie was built to constrain a new velocity model to better image the drowned carbonate platform and understand the reservoir potential of the drowning succession in the zone of interest using two complimentary techniques: seismic reservoir characterization and numerical stratigraphic forward modelling. The well-to-seismic tie was achieved by matching significant biostratigraphic events, such as unconformities, with seismic horizons using stratigraphy-to-seismic. Modern stratigraphic and seismic reservoir characterization techniques, including stratigraphy-to-seismic, numerical forward modelling, velocity model building, rock physics and seismic inversion, were applied to predict rock properties such as lithology and porosity within the drowning succession.

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We review mantle redox models and present new data for xenolithic and megacrystic intrinsic oxygen fugacity (IOF) studies from varied geologic settings. The roles of fluid inclusions, carbon, autoreduction, auto-oxidation, Ti 3+ , crystal defects, disproportionation, metasomatism, and gravity are examined with regard to their possible influences on redox data. In several IOF studies, the geothermometric determination for a multimineral sample yields very close temperature concordance with totally different geothermometric techniques; these specific studies mandate some confidence in the IOF f O 2 values obtained. Also of high confidence are the IOF data that come from nearly flawless, gem-quality megacrysts (GQ) of various silicates. Both types of these high-confidence IOF data indicate that the redox state of the mantle is nearer the wüstite-iron (WI) buffer than the quartz-fayalite-magnetite (QFM) buffer. The f O 2 data of the ilmenite-containing xenolithic assemblages that have either been calculated (Eggler, 1983), IOF-measured (Arculus and others, 1984), or gas mixture-equilibrated (McMahon, 1984) have all shown reasonable overlap in f O 2 -T values, and all indicate that these samples come from a mantle region more like (QFM). The ilmenitic xenoliths subjected to IOF analysis in our laboratory have exhibited auto-oxidation and therefore are difficult to interpret unequivocally. The high-confidence IOF data do argue strongly for mantle redox inhomogeneity, but much more work is needed to establish whether there is a general systematic redox decrease with depth into the mantle, on which the observed redox inhomogeneity is superimposed.