Note that this Record has now been published as Record 2014/050, GeoCat number 78802

Weathering, erosion and deposition are all around us. Without these processes we would not have our mountains, river valleys, sandy beaches or even the soil in which we grow our food. This booklet outlines the processes of weathering, erosion and deposition for the information of teachers and students. Inlcudes case studies about the formation of many Australian landforms such as Uluru, the Warrumbungles and the Bungle Bungles. The booklet also includes reproducible student activities that provide students with fun and easy ways to learn about the processes that shape the Earth. - 50 page booklet - 8 student activities - suggested answers A comprehensive resource to introduce your students to the concept of regolith, an important way of looking at, and mapping, the landscape. Suitable for primary Years 5-6 and secondary Years 7-12.

We examine surface sediment and water column total nutrient and chlorophyll a concentrations for 12 estuaries with average water depths <4 m, and calculated sediment loads ranging from 0.2 to 10.8 kg m-2 year-1. Sediment total nitrogen, phosphorus and organic carbon concentrations vary inversely with sediment loads due to: (i) the influx of more mineral-rich sediment into the estuaries; and (ii) increasing sediment sulfidation. Sediment total organic carbon (TOC) : total sulfur (TS) and TS : Fe(II) ratios correlated to sediment loads because enhanced sedimentation increases burial, hence the importance of sulfate reduction in organic matter degradation. Curvilinear relationships were found between a weathering index and organic matter 13C in sediment, and sediment load. The rising phase of the curve (increasing weathering, lighter isotopic values) at low to intermediate loads relates to soil erosion, whereas regolith or bedrock erosion probably explains the declining phase of the curve (decreasing weathering, heavier isotopic values) at higher sediment loads. The pattern of change for water column total nutrients (nitrogen and phosphorus) with sediment loads is similar to that of the weathering index. Most water quality problems occur in association with soil erosion, and at sediment loads that are intermediate for the estuaries studied. Limited evidence is presented that flushing can moderate the impact of sediment loads upon the estuaries.

Interpretation of apatite fission track and vitrinite reflectance data for samples from nine petroleum exploration wells in the eastern part of the Bowen and Gunnedah basins, eastern Australia, indicates that peak palaeotemperatures were reached during the Early Cretaceous, through progressive exposure to higher temperatures due to increased depth of burial. The palaeotemperatures were 28-58oC higher than at present. Cooling from the peak temperatures took place in the mid-Cretaceous, at some time during the interval 100-80 Ma, with the greatest amount of cooling occurring in the northern part of the study area. Palaeogeothermal gradients were generally in the range 21-35oC/km, similar to present day geothermal gradients in the region. The estimated maximum amount of denudation in the study area is approximately 1.9 km, with a significant portion of the eroded succession being Jurassic to Early Cretaceous in age. The synchronicity between the times of cooling inferred from all the sampled wells, regardless of their location with respect to the fault system near the present eastern margin of the Bowen Basin, suggests that the uplift was widespread, rather than being localised by faults during the mid-Cretaceous. This can be correlated with uplift along much of the eastern margin of Gondwanaland at the sme time, including all of eastern Australia, in New Zealand and in Marie Byrd Land, Antarctica. The onset of this mid-Cretaceous regional cooling and denudation coincided with a period of continental extension after the cessation of volcanism and subduction at about 95 Ma, and prior to the initiation of sea-floor spreading at about 84 Ma and formation of the current passive margin.

The Smartline Coastal Geomorphic Map of Australia is a detailed map of the coastal landform types - or 'geomorphology' of the whole of continental Australia and most adjacent islands (excluding the Great Barrier Reef). It has been compiled by combining mapped coastal landform data from over 200 diverse pre-existing datasets into a single nationally-consistent format and classification scheme. The Smartline map project was commissioned by the Department of Climate Change (formerly the Australian Greenhouse Office) and Geoscience Australia in 2007, because it was recognised that assessing the vulnerability of Australia's coast to sea-level rise required, amongst other things, detailed but national-scale mapping of coastal landform types.

To be completed

The floodplain of the lower Balonne River is in the upper reaches of the Murray Darling Basin. The region has been extensively developed for agriculture, in particular irrigated cotton, and is highly productive. Multidisciplinary investigations to inform land management generated extensive sets of remotely sensed data including Landsat TM, airborne gamma-ray radiometrics, aerial photography, ASTER imagery, and digital elevation models. These datasets provided the basis for regolith and geomorphic mapping. The wealth of data has allowed characterisation of the lower Balonne River system which is typical of many of the dryland rivers of southern Queensland. The geomorphic map of the lower Balonne floodplain has 8 major units based on landform and geomorphic processes. Bedrock consists of the slightly deformed and extensively weathered marine Cretaceous Griman Creek Formation. Coincident with erosion and weathering, Paleogene quartz gravels were deposited and are now extensively cemented and preserved as remnants forming zones of inverted relief. Much of the present landscape consists of a series of juxtaposed depositional units that have infilled an incised valley system. The different depositional units show the palaeo-Balonne River migrating to the west. This is interpreted to be a result of tectonic depression and tilting to the west, causing avulsion and anastomosing of the palaeo-channels. The modern Balonne River system consists of a number of easily recognised segments. In the north, the modern channel is incised as a single channel. To the south the channel opens out onto an anastomosing plain with branching and reconnecting small-scale channels. Source bordering dunes, currently inactive, have also formed along the western and eastern sides of the modern river and are prominent in large dunes in the south along the present Moonie River. Their absence in older landscape elements points to increasing aridity over time in the river system.

No abstract available

The morphology and chronostratigraphy of seven beach ridges at Beachmere, southeastern Queensland, Australia, provide a record of changes in shoreline accretion and relative sea level over the last 1,700 years. Optical dating of beds of pebbly sand that form the inner 7th ridge reveals that 1,700 -140 yrs ago relative sea level at the site was approximately 1 m higher than at present. During the subsequent 600 yrs, the coast prograded at ~ 0.16 m yr-1 until ridge 6 was emplaced 1,140 ?80 yrs ago; this increased to a rate of ~0.40 m yr-1 as ridges 5 (optical age: 860 ?70 yrs) to 1 (140 - 50 yrs) were emplaced. A relatively wide (~200 m) intertidal to supratidal flat between ridges 4 (690 - 60 yrs) and 3 (190 ?40 yrs) marks a change from well-defined and regularly spaced ridges, 7 - 4 (~ 95 m apart), to lower amplitude closely spaced ridges, 3 ? 1 (< 33 m apart). Ridges 3 ? 1 have Optical ages that overlap within their 1 ? uncertainty and probably represent a rapid phase of shoreline accretion related to an increase in sediment supply associated with European settlement. The optical age of ridge 1 (140 ? 50 yrs), which sits immediately behind the modern beach, provides a maximum age for the onset of the modern erosional regime at the site.

This record contains the raw Ground Penetrating Radar (GPR) data and scanned field notes collected on fieldwork at Old Bar and Boomerang Beaches, NSW for the Bushfire and Natural Hazards CRC Project, Resilience to Clustered Disaster Events on the Coast - Storm Surge. The data was collected from 3 - 5 March 2015 using a MALA ProEx GPR system with 250 MHz shielded and 100 MHz unshielded antennaes. The aim of the field work was to identify and define a minimum thickness for the beach and dune systems, and where possible depth to any identifiable competent substrate (e.g. bedrock) or pre-Holocene surface which may influence the erosion potential of incident wave energy. Surface elevation data was co-acquired and used to topographically correct the GPR profiles.