Detailed mapping, three-dimensional modelling and upscaling of a mixed-influence delta system, Mitchell River delta, Gulf of Carpentaria, Australia

Abstract

Data from satellite imagery, field measurements and analogues were used to construct a three-dimensional (3D) geocellular facies model of the Mitchell River Delta, Australia; a modern mixed-influence delta system. Detailed mapping identified 16 different facies elements and classified the delta as tide dominated, fluvially influenced and wave affected. The 3D model was subjected to varying degrees of upscaling of the horizontal and vertical dimensions and allowed comparison of volume and connectivity changes throughout. The upscaling process, to coarser grid cells up to 100 m horizontally and 4 m vertically, created false compartmentalization of facies bodies and significant changes in facies bulk volumes. The vertically upscaled models produced greater changes when compared to the horizontally upscaled models. Key changes in reservoir facies connectivity and bulk volume due to upscaling are associated with the facies architecture, including the elongate and thin morphology of beach ridge and channel facies in this mixed-influence delta system. Recognition of the defining reservoir features and incorporation into reservoir modelling methodology can improve volumetric estimation and allow for better predictions of reservoir connectivity in ancient delta systems.

Process variations of a Neoproterozoic delta system in response to the influence of mixed-energy systems and sea-level fluctuation: an insight from Simla Group, Lesser Himalaya, India

“…these deltas represent a coarsening upward subaqueous successions overlain by a fining-upward subaerial successions (delta plain deposits). But contrary to this, Table 2 shows that Pleistocene Arente delta (Fabbricatore et al 2014) and Holocene Mitchell River delta (Massey et al 2013;Lane et al 2016) exhibit fining upward succession (though mixedenergy processes prevailed during their development). When lithology and depositional trend is considered, the Chhaosa represents a sand-rich delta system like recent as well as ancient deltas such as Copper River delta (Galloway 1976), Mekong delta (Ta et al 2005(Ta et al , 2002aXue et al 2010) Gule Formation (Eide et al 2016) and Lajas Formation, (Rossi and Steel 2016).…”

The application of outcrop analogues in geological modelling: a review, present status and future outlook

“…The papers cover a range of clastic depositional environments from fluvial (Alsop et al 2013;Pranter et al 2013;Rittersbacher et al 2013;Keogh et al 2014;Nordahl et al 2014) through paralic (Massey et al 2013;Rarity et al 2013) to deep marine (Eschard et al 2013). Two deal with LiDAR and virtual outcrop techniques from a ground base (Rarity et al 2013) and from a helicopter platform (Rittersbacher et al 2013); ground-based LiDAR was also used by Keogh et al (2014).…”

“…The study by Massey et al (2013) of the modern Mitchell delta in northern Australia illustrated the value of modern analogues and the utilization of the wealth of high-quality freely available remote sensing data (such as Google Earth) that has become available to geologists in the last 10 years. In their study, sediment bodies were mapped from Google Earth and then quality controlled on the ground.…”

Use of Remote-Sensing to Quantify the Distribution of Progradation/erosion Along a Forced-Regressive Modern Coastline: Driving Factors and Impact on the Stratigraphic Record

“…1). High-frequency cyclic erosion and depositional styles and Holocene rates of progradation have been well-documented for these systems (Jones et al, 1993(Jones et al, , 2003Lane et al, 2017;Massey et al, 2014;Nanson et al, 2013;Porritt et al, 2020;Rhodes, 1982). The relatively limited anthropogenic modification of these systems over the last 200 years (Nanson et al, 2013) provides a natural laboratory to investigate the roles of various autogenic and allogenic controls on coastal change, and to frame considerations of preservation potential in the stratigraphic record.…”