Depositional history and paleogeography of the Jurassic Plover formation in Calliance and Brecknock fields, Browse Basin, North West Shelf, Australia

[Truncated abstract] The Early to Middle Jurassic Plover Formation in the Browse Basin (Australian North West Shelf) hosts reservoirs currently targeted for gas exploration and development. The depositional history and paleogeographic evolution of the Plover Formation in the Calliance and Brecknock fields has been established within a sequence-stratigraphic framework through integrated sedimentological analysis of core and borehole image and wireline log analysis incorporating biostratigraphic and seismic data. Seven siliciclastic and one volcano-sedimentary facies associations have been identified through facies analysis of core and interpreted as fluvial channel-fill (FA0), tidally influenced channel- and tidal channel-fill complex (FA1-FA2), crevasse-splay and interchannel marsh (FA3), heterolithic mouthbar (FA4), sandy mouthbar (FA5) and offshoretransition to offshore (FA6) depositional settings. These are associated with igneous and volcaniclastic rocks (FA7) that are distributed at different stratigraphic levels. Evaluation of borehole image fabric and interpretation of lithology from wireline log responses have been used to distinguish fourteen image facies grouped into six image facies associations (IFA0-IFA5). Paleocurrents obtained through image log interpretation show complex distribution of unimodal, bimodal (and bipolar) and polymodal patterns. Core-based and image log analysis have been used to interpret the depositional setting of the Plover Formation in the Calliance and Brecknock areas as a tidally influenced delta plain to delta front. Sandstone composition indicates that sediments were derived from a mixed provenance of recycled sedimentary and plutonic-metamorphic (cratonic) parent rocks. Igneous units are concentrated in the lower part of the formation and have been interpreted as extrusive flows, thus providing evidence for active volcanism during deposition. One shallow subvolcanic intrusion has been interpreted in Calliance-3...