The essence of stories of human-environment interactions can be preserved in oral contexts for millennia, creating novel opportunities for humanizing the past. This study examines stories (knowledge-rich narratives) about the ancestral being Ngurunderi, told by Ngarrindjeri peoples of South Australia. Three elements of the Ngurunderi narrative are considered. The first recalls his journey along a 170-km long coastal barrier (Younghusband Peninsula) when this was continuous. The second discusses Ngurunderi's encounters with what are now islands off the Fleurieu Peninsula, some of which he created, interpreted as memories of when sea level was lower and "islands" were contiguous with the mainland. The third refers to the crossing of a land connection between modern Kangaroo Island and the Fleurieu Peninsula, later submerged to form Backstairs Passage. Using paleogeographic data, the most recent times at which each narrative element could have taken place and observed by people are estimated. This research suggests that: (1) stories about Younghusband Peninsula may be >6700 years cal BP; (2) islands off the Fleurieu Peninsula were created 6800-10,400 cal BP; and (3) submergence of Backstairs Passage occurred 11,000-10,100 cal BP. Narratives are linked to the period of early Holocene sea-level rise, the rapid 8200-cal BP sea-level rise event, and stabilization of sea level 7000-6000 cal BP. These narratives humanize the past and provide information that can be interpreted as both observed coastal and seascape changes as well as past human responses to rising sea level that can inform our future encounters with coastal-landscape change.

The petroleum industry uses high level dynamic simulations applied to geocellular models to guide forecasts of oil, gas and water production. Uncertainty in model choice and input variable selection is often addressed through large numbers of computationally slow Monte Carlo simulations designed around physics based models. Here, an alternate approach is proposed, which uses a relatively small amount of data and a reduced number of simulations of the high level physics model to train a fast (to evaluate) proxy or surrogate model based on a Polynomial Chaos Expansion. We give details of the theory and incorporated techniques, which significantly increase flexibility. Input variables (e.g. cell-by-cell variations in porosity and permeability) are sampled from unknown probability distributions and sensitivity analysis is based on low level proxy models. The theory is tested by developing proxy models to predict total gas production from a five-spot well configuration in the Hermitage area that taps into the Walloon Coal Measures of the Surat Basin in Queensland. Synthetic training data is simulated using commercial dynamic simulation software based on a high level physics model.

The stratigraphy of the Surat Basin, Queensland, has historically been sub-divided by formation and unit nomenclature with a few attempts by other authors to apply sequence stratigraphy to existing formation boundaries. At a local- to field-scale, lithostratigraphy may be able to represent stratigraphy well, but at regional-scale, lithostratigraphic units are likely to be diachronous. To date, this lithology-driven framework does not accurately reflect time relationships in the sub-surface. An entirely new integrated methodological approach, involving well tied seismic data and sequence stratigraphic well-to-well correlations compared with published zircon age dates, has been applied to hundreds of deep wells and shallower coal seam gas wells. This method sub-divides the Surat Basin stratigraphy into defendable 2nd order to 3rd order sequence stratigraphic cycles and has required the use of an alpha-numeric sequence stratigraphic nomenclature to adequately and systematically label potential time equivalent surfaces basin-wide. Correlation of wells is the first step in building models of aquifers and coal seam gas fields for numerical simulation of fluid flow, which is necessary for responsible resource management. Lithostratigraphic correlations will overestimate the extent and hydraulic connectedness of the strata of interest. The result may be fluid flow models that do not represent a realistic pressure footprint of the flow. The present sequence stratigraphic method more accurately reflects the disconnectedness of sub-surface coals and sandstones (aquifers) on a field-to-field scale, adjacent field-scale, and basin-wide scale. It forms the basis for improved and more representative modelling of the sub-surface.

Coal Seam Gas (CSG) is a significant resource; it makes up 90% of the gas production in Queensland, Australia, most of it from the Surat Basin Walloon Coal Measures, (WCM). However, coal connectivity and distribution are poorly understood resulting in production and modelling challenges. Simplistic, homogeneous models cannot adequately explain volumes or flow rates of gas and water. Initially, the focus of the industry was on optimizing drilling, often without the aid of seismic data, relying on correlations based on wireline logs and cores alone. Those correlations were often based on lithology, and connected sand with sand and coal with coal. Those models seem to overestimate flow between wells and volumes of hydrocarbons or water (Cardwell, 2018). Here, log interpretation is integrated with 3D seismic using a sequence stratigraphic framework. Special attention is placed on the architecture of the WCM revealed by seismic. Seismic mapping of individual coal seams in the Springbok Sandstone or the WCM is difficult on a field scale. Most coals are below seismic resolution, yet have a strong influence on seismic amplitudes. Four methods of spectral decomposition are compared and evaluated on how well they predict known geology at many well locations throughout the 3D seismic survey. Sequence stratigraphy applied to core and log interpretation integrated with seismic produces an improved view of coal distribution and geometries. Coals are mostly thin and discontinuous and segregated by channels cutting through them that appear to be meandering through flood plains. Coal forms along channels and sands are likely to be present in point bars. Therefore, sands or coals identified in wireline logs are not likely to be connected to a large sand sheet, but are rather individual channels or sand bodies likely to be hydraulically isolated. In the next phase, it will be investigated how results of spectral decomposition can be used inform geostatistical algorithms for modelling to produce more representative static geological models.

The Walloon Coal Measures in the Surat Basin are the main target for Coal Seam Gas (CSG) production in Queensland. They are overlain by the Springbok Sandstone, although consistently identifying the boundary between these two extremely heterogeneous intervals is challenging, and different stratigraphic methods may lead to quite different interpretations. This paper discusses the challenges associated with identifying the Walloon-Springbok boundary and highlights some potential impacts of using alternate interpretations of the boundary. Ulimately, resolving this challenging geology is important because different correlations impact the vertical and horizontal propagation of pressure in groundwater and reservoir models.

A new sequence stratigraphic framework (SSF) for the Early–Late Jurassic Surat Basin, eastern Australia, is evolving. A second and third order framework based upon an integrated methodology of well-to-well correlations supported by well tied seismic data is being developed. The integration of an additional dataset (palynology) to test for regionally consistent sequence stratigraphic well correlations offers an improvement in defining sequence boundaries related to the geological timescale. The palynological data from 33 wells covering the north-east Surat Basin were extracted from the Queensland Digital Exploration (QDEX) open-file reports, some of which date back to the 1960s. These data were correlated and superposed on the SSF for age comparison. The dataset used in this study represents only a subset of all existing palynology information, as not all data are captured in QDEX. However, the palynology data in this exploratory study generally fits and supports the new SSF with only one exception, the reason for which is not understood at this stage. We recommend expanding this study to include more data because palynology can support stratigraphic interpretation, especially in wells that do not intercept, or have log data across, regional datums.

The Precipice Sandstone and Evergreen Formation in the Surat Basin, Queensland, are being examined as a reservoir-seal option for future geosequestration of CO2. Effective reservoir modelling, and prediction of dynamic storage capacity, however, depends upon accurate depositional interpretations relating to an understanding of the stratigraphic architecture. Throughout most of the basin, the Precipice Sandstone is generally considered to have good reservoir properties and lateral continuity. Refined depositional models and a widely-applied sequence stratigraphic framework will enhance prediction of the most prospective play segments for CO2 injection.We utilize integrated ichnological-sedimentological facies analysis from core to interpret the Precipice Sandstone as a braided fluvial to braid-delta succession, overlain by lower delta plain to subaqueous delta and estuarine embayment deposits of the Evergreen Formation. Facies successions and core-calibrated wireline logs show brackish-water influenced deposits at several stratigraphic intervals. Brackish-water influenced deposits overlie upper delta plain or braid-plain sediments. They occur laterally adjacent to subaerial lower delta plain strata, and generally cap parasequence-sets. Seismic surveys resolve lower-order cyclicity, showing parasequence-sets within the Precipice succession that retrograde or aggrade and onlap the basal-Surat unconformity. This stratal arrangement reflects the lowstand and early transgressive systems tracts of a 2rd order depositional sequence or a distinct 3th order sequence. Late transgressive and early highstand systems tracts are more abundant within the lower Evergreen Formation and are interpreted to consist of restricted or estuarine central basin deposits; but these may also represent a 3th order sequence. Additional chronometric data is needed to differentiate between these interpretations.Depositional and sequence stratigraphic interpretations suggest the Precipice Sandstone has a higher degree of heterogeneity than previously appreciated. Moreover, we show that the Evergreen Formation is not a simple basin-wide sealing unit due to the presence of sandstone geobodies that complexly cross-cut each other (i.e., the ‘Boxvale Sandstone Member’) that may act as vertical fluid conduits. The sequence stratigraphic characteristics of the reservoir-seal pair should be carefully considered when selecting locations for CO2 sequestration.

The study of modern sedimentary systems and their biotic and abiotic characters are important to produce ichnologic proxies to interpret depositional environments, their biophysicochemical characters, and their variations through short- and long-term timeframes. Research has been conducted on rivers and estuaries of Moreton Bay, however, little work has focused on the neoichnology and its implications to interpreting deep time deposits. Here we provide examples of how the neoichnology reflects the physicochemical conditions in the southern part of this back-barrier system. Moreton Bay contains various depositional environments, bed forms, and geobodies produced by fluvial, tidal, and wave processes. Despite the fluvial input, marine trace-making organisms dominate most of the Moreton Bay ichnology, with the exception of vegetated islands and strandlines that compose the back-barrier islands. Portions of the mouth bar of Logan River are subaerially exposed at low tide. This mud-dominated, coarsening upward succession of fine- to medium-grained sand is highly bioturbated by such necktic and epi- and endobenthic organisms as callianassid shrimp, solider crabs, polychaete worms, a variety of gastropods and bivalves, stingrays, and fishes. This activity produces such trace fossils as Ophiomorpha, Taenidium, Skolithos, Thalassinoides, Planolites, Palaeophycus, Taphrahelminthopsis, Helminthopsis, Lockeia, and large- and small-scale Piscichnus. These traces are overprinted by anisodactyl, incumbent anisodactyl, semipalmate, and palmate bird tracks with associated feeding marks. Such vegetated islands as Kangaroo Island in the Tiger Mullet estuary are dominated by marine crab burrows along the island margins, as well as inland in low-lying areas; mangrove vegetation shows the same pattern. Inland, the island contains grasses and conifers. Root patterns are extremely shallow and nearly horizontal due to the shallow water table. Subaerial sediments experience pedogenesis mediated by solitary, gregarious, and social insect bioturbation, with gleyed- and redoximorphic-mottled patterns associated with incipient peds and crab burrow walls. Gold bank, the eastern tip of Kangaroo Island, contains similar biota to the Logan River mouth bar, but is dominated by soldier and fiddler crabs and stingray feeding pits, which thoroughly bioturbate the fine-grained sand, except where tidal and wave energy rework the sediment.

Abstract Ichnofossils and paleosols are powerful tools for reconstructing paleoenvironments and depositional histories of sediments in the coastal transition zone, where physicochemical factors of the continental and marine realms meet. Distinguishing alluvial, coastal-plain, deltaic, and estuarine environments in this zone is a major issue in outcrop and core. Alluvial environments contain terrestrial and freshwater ichnofossils and paleosols, although deposits in paralic settings may record tidal influence as evidenced by mud drapes, reactivation surfaces, and bidirectional crossbeds. Deltaic, estuarine, and coastal-plain environments contain a variety of marine, terrestrial, and freshwater ichnofossils and paleosols, depending on the salinity, sedimentation rate, groundwater profile, water oxygenation, and depositional-energy flux from fluvial, wave, and/or storm action. Delta-plain environments commonly contain weakly to moderately developed, poorly aerated, and waterlogged paleosols formed in proximal-to-distal settings. Ichnofossils and palynomorphs in the lower delta plain, including the distributary-channel, interdistributary-floodbasin, and associated lacustrine deposits, may reflect fluctuating salinity from freshwater to brackish water. Interdistributary-bay deposits commonly resemble deposits of estuarine settings, recording freshwater through brackish to open-marine water salinities. More marine conditions favor an increase in marine ichnofossil diversity and abundance. Environmental stress resulting from the input of freshwater, fine-grained sediments, and/or terrigenous organic material are recorded by lower ichnofossil diversity and/or greater abundance; freshwater deposits record few and simple ichnofossils not indicative of a particular animal or environment. Subsequent subaerial exposure of these settings by sea-level fall or strandline progradation produce a vertical sequence containing marine ichnofossils overlain by traces of terrestrial plants and animals commonly associated with paleosols. In many cases, continental ichnofossils and other pedogenic features overprint marine ichnofossils and facies. The juxtaposition, tiering, and crosscutting relations among ichnofossils and paleosols in the coastal transition zone, therefore, differentiate sediments deposited in alluvial, coastal-plain, estuarine, and deltaic environments. Introduction The purpose of this paper is to provide a brief overview and synopsis of the use of ichnofossils (i.e., trace fossils) and paleosols for reconstructing the depositional history of sedimentary successions in core and outcrop. In particular, we focus on sedimentary successions formed in alluvial, coastal-plain, and deltaic settings—the transition zone where continental and marine depositional systems and physicochemical controls meet. Here, fluvial, lacustrine, eolian, and palustrine (paludal) systems grade into and interfinger with the marine realm to create beaches, deltas, bays and estuaries, and barrier shorelines and islands (e.g., Reineck and Singh, 1980). Identification of trace fossils and paleosols, when used in conjunction with lithofacies and the understanding of their formation, help identify environments of deposition, subdivide lithofacies and depositional environments, interpret changes in salinity between freshwater and marine aquatic settings, and delineate relative changes in sea level (e.g., Hasiotis, 2002; MacEachern et al., 2007a).

Many publications on lacustrine systems concentrate on reconstructing paleo-environments, deciphering paleoclimate or estimating hydrocarbon source potential. This is the first memoir to give attention to describing the occurrence, distribution and character of sandstones in various lake settings. the volume is the outcome of a Hedberg Conference held in Baku, Azerbaijan in 2004. The memoir is divided into four sections beginning with a global overview, and followed by two sections covering lacustrine systems in compressional and extensional regimes. The volume concludes with a series of papers on modern lake regimes.

Ephemeral sandy fluvial-lacustrine deltas and terminal splays associated with dryland depositional environments are important reservoirs in many basins around the world, in both pericratonic and intracratonic settings (Triassic of Algeria; Triassic of the North Sea; and Pliocene of the Caspian Sea). Research on modern depositional analogues from dryland basins offers insights into these types of reservoirs. Australia’s modern Lake Eyre Basin, an arid to hyper-arid, low-accommodation intracratonic basin in central Australia, provides an ideal natural laboratory.This paper highlights field observations of modern, sand-prone, reservoir analogues from the Neales River and Umbum Creek, on the western fringe of Lake Eyre, including unique aerial observations of sedimentation from a rare flood event in an ephemeral fluvial system. These rivers flow irregularly in a dryland setting, but are prone to flash flooding and highly variable discharge that moves large volumes of sediment over a few hours or days. Although there are variations in sediment type and discharge, similarities exist with the key reservoir elements common to most modern and ancient dryland fluvial-lacustrine systems.Distinctive elements include fluvial point bar and associated overbank deposits, distributive avulsion channels and down-dip terminal splays, either on the floodplain or onto the playa lake fringe. The terminal splays are formed, where there is not a pre-existing standing body of water, during rapidly decelerating flows with high-flow regime, transitional to low-flow regime conditions. Typical structures include parallel lamination, convex-upward parallel lamination, climbing ripples and small-scale 2D and 3D dunes. Flow interference with in-channel and floodplain vegetation is an important sediment-trapping mechanism with reservoir quality implications. Aeolian deflation is also significant as it causes the removal of fine-grained sediments during dry periods. The main controls on sediment preservation include the overall low-accommodation setting and rare major lake-filling events controlled by flooding out-of-phase with flows down the western rivers. Depositional products are either high-net-to gross fluvial- terminal splay sheet sands or lower net-to-gross fluvial- terminal splay-lacustrine delta sand sheets or stringers.

The Donkey Bore Syncline in the Northern Flinders Ranges of South Australia contains a generally finegrained deepwater succession of Early Cambrian age (Bunkers Sandstone) that outcrops on three sides of a syncline and flanks an active salt diapir to the east (Wirrealpa Diapir). Within the succession lies a basal sand-prone interval interpreted as a basin floor fan (BFF) ponded within a mini-basin on a topographically complex slope.The BFF comprises over 30 m of section with deposits that are dominantly massive clean sandstone beds (0.1– 3 m thick) that are stacked or interbedded with siltstones and pinch out along strike.Eight stratigraphic sections and accompanying spectral gamma ray logs (using a hand held scintillometer) were measured through the BFF. Using spectral gamma ray log analysis combined with stratigraphic logs, four alternative correlation panels were constructed.Quantitative analysis of sand-prone intervals interpreted in each of the panels provided data on the vertical and horizontal connectivity within the BFF as different correlation methods were explored and the geological model improved. Quantitative analysis of vertical and horizontal connectivity values indicates a high degree of heterogeneity within the BFF, with poor–moderate vertical connectivity, with individual beds rarely correlating >500 m along strike. This heterogeneity is poorly resolved using conventional wireline log suites, but is greatly improved if spectral gamma ray logs are used (especially Thorium).The data set provides a high-resolution analogue for understanding the internal architecture of deepwater hydrocarbon reservoirs.