Geomorphic landscape features and associated surface materials are fundamental to groundwater recharge processes as they form the first layer through which surface water passes before it becomes groundwater. Different surface materials exhibit different water-holding capacity and hence permeability characteristics. In the Broken Hill Managed Aquifer Recharge project, surface-materials mapping in conjunction with geomorphic mapping, has assisted hydrogeological investigations, including recharge predictions, salinity hazard and the identification of potential infiltration basins. Prior to landform identification, LiDAR DEM data was levelled using trend surfaces to eliminate regional slope (~20m). As a consequence of this, an ArcGIS interactive contour tool could be used to identify specific breaks in elevation associated with landform features. Multivariate image analysis of elevation, high resolution SPOT and Landsat-derived wetness further enhanced the contrast between geomorphic elements to confirm mapping boundaries. While specific landforms can be characterised by particular surface materials, these sediments can vary within a single geomorphic feature. Consequently, SPOT multispectral satellite imagery was used to identify surface materials using principal component analysis and unsupervised classification. This approach generated 20 classes; each assigned a preliminary cover/landform attribute using SPOT imagery. Field data (surface and borehole sample, and observations at shallow pits) were used to refine the classification approach. Interactive mapping using a de-trended DEM provided a rapid, effective and accurate alternative to time consuming manual landform digitisation. The combination of these two new products - surface-materials and geomorphic maps - has assisted in the identification of potential recharge sites and naturally occurring infiltration sites.

The Ord is one of the largest rivers in northern Australia and is located in the Kimberley region of Western Australia. In this study we show that the lower Ord landscape near Kununurra in Western Australia consists of a large scale ancient landscape, possibly pre-Cambrian, being exhumed from beneath flat-lying Cambrian to Carboniferous cover rocks. Additional post-Permian landscapes are being formed by this process. The Ord Valley alluvium is of late Pleistocene to Holocene in age and consts off upward fining gravels, sands and clays infilling an inset valley profile. The Ord River initially flowed to the sea via the keep River estuary, however a major avulsion, possibly due to sedimentatain topping a low point in the surrounding valley walls, occurred possibly as recently as 1,800 years ago. As a result to mouth of the Ord shifted some 100 km to the east, to Cambridge Gulf, its course through the former alluvial plain and along the new course across the coastal plain was incised, and a scabland formed across the low point of Tararar Bar. This association of very ancient (pre-Paleozoic) landscape elements and by thin, very young weathering profiles and young sedimentary accumulations in alluvial valleys is paradoxical in the broader Australian pattern where very ancient landscape elements are associated with ancient sedimentary infill and weathering profiles.

An examination of regionally extensive hill-shaded SRTM 90m resolution and DLI 10 m resolution digital elevation data and discussions with government and industry geologists familiar with the local geology has resulted in the identification of thirty eight previously unrecognised linear topographic scarps in the southwest and central west of Western Australia. I contend that most of these relate to Quaternary surface-rupturing earthquakes. If validated, this more than doubles the number of Quaternary fault scarps known from this area, bringing the total to sixty. The newly recognised scarps average between 25 km and 50 km in length and from ~1.5 m to 20 m in height. The geometric, recurrence and spatial attributes of these features makes it possible to propose a model describing the causative seismicity. The model contends that uniform contractional strain in the ductile lithosphere manifests as localised, transient and recurrent brittle deformation in zones of pre-existing crustal weakness in the upper lithosphere. The data presented allow for ready calculation of the maximum probable magnitude earthquake for the southwest of Western Australia, and identify 'earthquake prone' regions of interest to seismic hazard assessors.

Literature review and spatial analysis of the sedimentology and geomorphology of the Northwest Marine Region (boundary as defined by the Department of the Environment, Water, Heritage and the Arts 2007). Sedimentology information is based on consistent quantitative point assays of grainsize (weight % sand/mud/gravel) and carbonate content (weight % carbonate) of sediments in the MARS database at 01/08/07.

This record is a review and synthesis of geological research undertaken along the south western margin of Australia. The record has been written in support of regional marine planning and provides fundamental baseline scientific information for the South Western Marine Planning Area.

Measured probability distributions of shoreline elevation, swash height (shoreline excursion length) and swash maxima and minima from a wide range of beach types are compared to theoretical probability distributions. The theoretical distributions are based on assumptions that the time series are weakly steady-state, ergodic and a linear random process. Despite the swash process being inherently non-linear, our results indicate that these assumptions are not overly restrictive with respect to modeling exceedence statistics in the upper tail of the probability distribution. The RMS-errors for a range of exceedence level statistics (50, 10, 5, 2, and 1 percent) were restricted to <10 cm (and often <5 cm) for all of the swash variables that were investigated. The results presented here provide the basis for further refinement of coastal inundation modeling as well as stochastic-type morphodynamic modeling of beach response to waves. Further work is required, however, to relate the parameters of swash probability distributions to wave conditions further offshore.

This report describes the field survey carried out in Cockburn Sound, Western Australia by Geoscience Australia (GA) staff for the Coastal Geomorphology and Classification Subproject (CG) of the Coastal Water Habitat Mapping Project (CWHM). It documents the various sampling techniques and procedures used to collect surface and subsurface samples from the Sound; details of the vibracores and grab samples recovered and the proposed analyses to be performed on these samples. The results of the analysis of the grab samples will be used to classify the various surface sediment types encountered as well as map their distribution within Cockburn Sound. The analysis and interpretation of the vibracores will allow the reconstruction of the stratigraphic framework of Cockburn Sound. This information will be used in conjunction with the findings of the other subprojects in the CWHM Project. For example, it will assist in ground-truthing the results of the both the single and multi-beam sonar surveys that have and are to be carried out within Cockburn Sound by Curtin University. It will also provide key substrate information for incorporation into a more comprehensive benthic habitat classification for the sound.

Keppel Bay is a macrotidal environment that represents the interface of the large catchment of the Fitzroy River with the southern GBR continental shelf. In this study, we assessed the distribution of sediments and their depositional characteristics using a combination of sediment sampling, and acoustic (sonar) seabed mapping tools. Using statistical techniques, we classified the seabed sediments of Keppel Bay into five distinct classes, based on sediment grainsize, chemical composition, and modelled seabed hear stress (the influence of waves and tidal currents).

Controls on the evolution of Tapora Island, an active barrier island located opposite the entrance to the Kaipara Harbour on the high-energy west coast of the North Island of New Zealand are identified. Subsurface facies form an aggradational barrier island succession from subtidal to subaerial elevations. These data, combined with surface samples and geomorphic and geologic relationships, indicate that Tapora Island is the most recent barrier island at this location in the estuary, and forms part of a prograded coast opposite the entrance. Wave data indicate that ocean swell waves penetrate the inlet for approximately two hours either side of high tide and are capable of transporting sand onto the island. The combined effects of swell waves, abundant sediment supply, and exposed aspect are the critical factors that have formed the barrier island. Despite the 'sheltered' estuarine setting, Tapora Island has formed under conditions that are more akin to open ocean coasts. The origin and development of Tapora Island broadly conforms to the accumulating barrier island model.

Measurements of water turbidity, currents, seafloor sediment samples and geophysical data document the sedimentary processes and the Late Quaternary sedimentary history of a continental shelf valley system on the East Antarctic continental margin.