Palynofacies, organic geochemistry and depositional environment of the Tartan Formation (Late Paleocene), a potential source rock in the Great South Basin, New Zealand

Significance of sedimentary organic matter input for shale gas generation potential of Mississippian Mudstones, Widmerpool Gulf, UK

“…The discrete gelified OM particles (G) have features in common with phytoclasts, including clear outlines and equant-or lath-like shapes, and particles of similar appearance have been described as degraded phytoclasts by Schiøler et al (2010). It is known that gelified material can be derived from the diagenetic alteration of plant tissue through hydrolysing reactions (e.g.…”

Paleocene–Eocene stratigraphy and paleoenvironment at Tora, Southeast Wairarapa, New Zealand

“…Combined with the dominance of agglutinated taxa (>90%), this indicates a middle to lower bathyal depositional environment. The scarcity of calcareous benthic taxa and the complete absence of planktic foraminifera are typical of Upper Cretaceous and Paleocene sediments of eastern New Zealand, apparently independent of water depth (Moore 1988b;Schiøler et al 2010). The cause is uncertain but this may be the consequence of a combination of factors: high sedimentation rates, relatively cool ocean conditions causing carbonate dissolution or post-depositional dissolution during diagenesis.…”

“…The well-bedded character of the middle member with sharp basal contacts, cross-bedding and normal grading indicates deposition by turbidity currents. The inclusion of a Waipawa Formation-like facies near the base of the upper member suggests an influx of terrestrial organic matter and a possible fall in eustatic sea level (Schiøler et al 2010). The upper member of the Mungaroa Limestone primarily reflects pelagic deposition with minor terrigenous input, with occasional influx of glauconitic sands as redeposited sediments within this otherwise low-energy pelagic environment (Browne 1987).…”

“…In some areas, an organic-rich correlative unit occurs in the uppermost Te Uri Member, also directly underlying the Wanstead Formation (Moore 1988b;Rogers et al 2001;Tayler 2011). Recent studies suggest that the Waipawa Formation is a regressive facies deposited during a fall in global sea level in the early Late Paleocene (Schiøler et al 2010). North of Tora, the unit also appears to herald a longer-term transition from the weakly cal-careous facies of the Whangai Formation to the more calcareous mudstones typical of the Wanstead Formation (Field et al 1997).…”

Hydrocarbon generation modeling and source rock characterization of the Cretaceous–Paleocene Taratu Formation, Great South Basin, New Zealand

“…1), with dimensions extending approximately up to an area of 100,000 km 2 (Evans 1982;Killops et al 1997). This basin comprises primarily grabens and half-grabens, containing sediments from the Late Cretaceous to Early Tertiary (Schiøler et al 2009;Evans 1982;Beggs 1993;Cook et al 1999). Based on hydrocarbon potential studies undergone by Killops et al (1997), Cook et al (1999), and Constable et al (2013), this basin is found to contain promising source rocks despite not having a commercial hydrocarbon production and limited exploration.…”