This is a compilation of all the processed multibeam bathymetry data that are publicly available in Geoscience Australia's data holding for the Macquarie Ridge.

This report presents the geomorphology and sedimentology of the East Marine Region. The three main outputs of the report include: 1) a review of previous geological research undertaken in the East Marine Region (EMR); 2) the results of a quantitative study of seabed sediment texture and composition for these regions; and 3) a synthesis of this information characterizing regional trends in sedimentology, geomorphology and bathymetry. The study is a collaboration between Geoscience Australia and the Department of the Environment, Water, Heritage and the Arts (DEWHA) and is a continuation of similar work conducted for the North West Marine Region (Potter et al., in press; Baker et al., 2008) and the South West Marine Region (Richardson et al., 2005). By combining results of previous qualitative work and quantitative information generated from existing and new data, this report provides an improved understanding of sedimentology for the EMR. Information contained within this report will contribute to the Department of the Environment, Water, Heritage and the Arts national work program and will also assist in the marine bioregional planning for the East Marine Region. Previous sediment studies in the EMR have predominantly produced qualitative results at local scales. Geomorphic, sedimentary and biological information has previously been utilised to develop a National Bioregionalisation of Australia's Exclusive Economic Zone (EEZ) (Department of the Environment and Heritage (National Oceans Office), 2005; now the Department of the Environment, Water, Heritage and the Arts) and substantive geomorphic features of the eastern continental margins have already been identified and mapped (Heap and Harris, in press). This report adds significantly to these previous studies by incorporating the information in a sedimentological synthesis that includes a discussion of the implications for marine conservation in the EMR. The physical characteristics of the seabed in the EMR, as described by the sediment texture and composition data, can assist in determining the diversity of benthic marine habitats in the EMR. These data represent enduring features which are elements of the physical environment that do not change considerably and they are known to influence the diversity of biological systems. This is important for marine conservation by contributing to the better definition and characterisation of benthic habitats. Seabed texture and composition are easily measurable parameters that when combined with other physical features can be used to create "seascapes" that serve as broad surrogates for benthic habitats and biota (Whiteway et al., 2007). Seascapes have the potential to be used in informing the marine bioregional planning process.

The Petrel Sub-basin Marine Environmental Survey GA-0335, (SOL5463) was undertaken by the RV Solander during May 2012 as part of the Commonwealth Government's National Low Emission Coal Initiative (NLECI). The survey was undertaken as a collaboration between the Australian Institute of Marine Science (AIMS) and GA. The purpose was to acquire geophysical and biophysical data on shallow (less then 100m water depth) seabed environments within two targeted areas in the Petrel Sub-basin to support investigation for CO2 storage potential in these areas. This dataset comprises an interpreted geomorphic map. Interpreted local-scale geomorphic maps were produced for each survey area in the Petrel Sub-basin using multibeam bathymetry and backscatter grids at 2 m resolution and bathymetric derivatives (e.g. slope; 1-m contours). Five geomorphic units; bank, plain, ridge, terrace and valley, were identified and mapped using definitions suitable for interpretation at the local scale (nominally 1:10 000). Maps and polygons were manual digitised in ArcGIS using the spatial analyst and 3D analyst toolboxes.

This cross agency report, highlights the areas of the central NSW continental slope prone to sediment mass wasting over time. It includes the critical factors which contribute to slope failure including basement geometry, angle of slope and thickness of overlying sediments. Evidence of slope failure are observed through: surficial tension cracks; creep features; faulting; redistribution of sediments, multiple relict slides on the sea floor and erosional surface scars.

This record summarises the physical environments of the seabed for the Ceduna and Eyre Sub-basins.

In a recent paper, Dye (2006) analyzed the distribution of species of macrobenthos and meiobenthos within two geomorphic facies of four small intermittently closed and open estuaries in New South Wales, Australia (colloquially known as ICOLLs). We believe that Dye's (2006) study is not an appropriate test of the Roy et al. (2001) habitat classification, and consequently several of the hypotheses posed by Dye do not follow logically from their model.

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In 1946 and 1947 the writer had excellent opportunities to study the effect of lateritisation in the course of geological reconnaissances in Northern Australia. From field evidence which has been collected on several aspects of lateritisation - origin, products and relationship to geomorphological processes - a detailed account of lateritisation in Australia can be given. Lateritisation and the occurrence of opal are discussed in this report.

Faults of the Lapstone Structural Complex (LSC) underlie 100 km, and perhaps as much as 160 km, of the eastern range front of the Blue Mountains, west of Sydney, Australia. More than a dozen major faults and monoclinal flexures have been mapped along its extent. Debate continues as to the age of formation of the ~400 m or more of relief relating to the LSC, with estimates ranging from Palaeozoic to Pliocene. The results of an investigation of Mountain Lagoon, a small basin bound on its eastern side by the Kurrajong Fault in the central part of the LSC, favour a predominantly pre-Neogene origin. Drilling on the eastern margin of the lagoon identified 15 m of fluvial, colluvial and lacustrine sediments, overlying shale bedrock. The sediments are trapped behind a sandstone barrier corresponding to the Kurrajong Fault. Dating of pollen grains preserved in sediments at the base of this sediment column suggest that the fault-angle depression began trapping sediment in the Early to Middle Miocene. Strongly heated Permo-Triassic gymnosperm pollen in the same strata provides circumstantial evidence that sediment accumulation post-dates the ca. 18.8 Ma emplacement of the nearby Green Scrub basalt. Our data indicate that only 15 m of the 130 m of throw across the Kurrajong Fault has occurred during the Neogene suggesting a predominantly erosional exhumation origin for current relief at the eastern edge of the Blue Mountains plateau. Sedimentation since the Late Pleistocene appears to have been controlled largely by climatic processes, with tectonism exerting little or no influence.

In order to protect the diversity of marine life in Australia's Exclusive Economic Zone (EEZ), the federal parliament has passed the Environmental Protection and Biodiversity Conservation (EPBC) Act 1999. The Act is being implemented through the design of a national representative system of marine protected areas (MPAs) that will place under protection a representative portion of Australia's EEZ by 2012. A total of 13 MPAs have already been nominated for the southeast region in 2006. Limited biological data in Australia's EEZ has resulted in biophysical information compiled by Geoscience Australia being used as a proxy for seabed biodiversity in support of marine conservation planning. Information we use to characterise the seabed includes bathymetry, geomorphology, acoustic properties, sediment properties, slope and sediment mobilisation due to waves and tides. To better characterise habitats on the Australian continental shelf, Geoscience Australia is creating 'seascape' maps (similar to geological facies maps) that integrate these multiple layers of spatial data, and are useful for the prediction of the distribution of biodiversity in Australia's EEZ. This information provides 100% spatial coverage based on objective, multivariate statistical methods and offers certainty for managers and stakeholders including the oil and gas industry, who are involved with designing Australia's national MPA system. Certainty for industries operating in the EEZ is enhanced by a reproducible, science-based approach for identifying conservation priorities and the classification of seafloor types within multiple use areas.