The role of neotectonism in the recent landscape evolution of the Eastern Blue Mountains, NSW Dan Clark, Andrew McPherson and Kerrie Tomkins 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. More than a dozen major faults and monoclinal flexures have been mapped along its extent. The Lapstone Monocline is the most prominent of the flexures, and accounts for more than three quarters of the deformation across the complex at its northern end. Opinion varies as to whether recent tectonism, erosional exhumation of a pre-existing structure, or a combination of both, best accounts for the deeply dissected Blue Mountains plateau that we see today. We present results from an ongoing investigation of Mountain Lagoon, a small fault-bound basin bordering the Kurrajong Fault in the northern part of the LSC. Drilling has identified 15 m of fluvial, colluvial and lacustrine sediments overlying shale bedrock trapped behind a sandstone fault barrier corresponding to the Kurrajong Fault. Dating of pollen grains preserved in the basal sediments overlying shale 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 postdates the emplacement of basalts at Green Scrub at ca. 18.8 Ma. Our results indicate that only 15 m of the 130 m of throw across the Kurrajong Fault is Neogene in age. From this it may be deduced that erosional exhumation is the dominant process responsible for formation of the deeply dissected Blue Mountains landscape. However, it is also possible to demonstrate the influence of ongoing tectonism on stream channel over-steepening, knick point initiation, and the continuing dissection of the plateau.

For the purpose of obtaining a general understanding of the geology of North Stradbroke Island, field work was carried out on the island from January 8th to February 17th, 1948. Altimeter traverses were made from Dunwich, Amity, Point Lookout and Blue Lake, and from the connecting roads. The southern portion was covered from landing points on the west coast near Russel Island. The results of observations were plotted on to Military Map Queensland Zone 8, No. 182 (Brisbane Valley). Altimeter readings were corrected from the readings of a weekly barograph stationed at Dunwich, on the western side of the island. This report is comprised in two parts. In Part I, the physiography and the geology of the island are described. In Part II, an account is given of the history of the development of the island.

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.

The overarching theme of this book (and for the GeoHab organisation in general) is that mapping seafloor geomorphic features is useful for understanding benthic habitats. Many of the case studies in this volume demonstrate that geomorphic feature type is a powerful surrogate for associated benthic communities. Here we provide a brief overview of the major geomorphic features that are described in the detailed case studies (which follow in Part II of this book). Starting from the coast we will consider sandy temperate coasts, rocky temperate coasts, estuaries and fjords, barrier islands and glaciated coasts. Moving offshore onto the continental shelf we will consider sandbanks, sandwaves, rocky ridges, shallow banks, coral reefs, shelf valleys and other shelf habitats. Finally, on the continental slope and deep ocean environments we will review the general geomorphology and associated habitats of escarpments, submarine canyons, seamounts, plateaus and deep sea vent communities.

Continental Australia is characterised overall by relatively high levels of seismic activity in comparison with intracratonic areas worldwide. However, the link between earthquake events and earthquake-related geomorphology in Australia remains poorly understood for all except the largest events, because landscape impact unambiguously attributable to seismic activity is typically difficult to recognise. In this context, we describe several unusual fracture systems of possible tectonic origin that transect granite pavements in the Archaean eastern Pilbara Craton of Western Australia. Occurring at four localities (Gallery Hill, North Shaw, Mulgandinnah Hill and Muccan) separated by up to 150 km, the fracture systems typically range up to 100 m in length and 20 m in width, locally offset pavement surfaces by up to 15 cm vertically, and expose uniformly fresh-looking rock. At one locality (Muccan), the fractures directly crosscut two generations of aboriginal petroglyphs etched into the pavement surface, which suggests that fracture formation occurred relatively recently, and probably quite rapidly. All four localities are characterised by extensional structures (tension fractures and dilated joints) striking 020?040?, and three preserve compressional structures (steeply-dipping reverse faults at Gallery Hill and North Shaw, A-tent crestal fractures at Mulgandinnah Hill) trending 100?135?. These strongly correlated alignments militate against an origin controlled purely by weathering-related phenomena, and the observed pattern is compatible with the formation of all documented fracture systems within a single East Pilbara-wide stress field, dominated by pure shear and characterised by NE?SW to NNE?SSW directed maximum horizontal compression. This orientation is consistent with that derived via spatial averaging of the stress orientation data available from northwestern Australia. The results are preliminary, but have exciting implications for: (1) inexpensive field-based determination of regional stress orientation, and (2) probabilistic seismic hazard assessment and the identification of earthquake-prone regions using granitic landforms.

A short article as a side bar in the Australian Antarctic Magazine published by the Australian Antarctic Division. The sidebar article will accompany a longer article by Lt Peter Waring of the Royal Australian Navy survey team that conducted a multibeam survey in Casey Harbour during season 2013-14

The historical record reveals that at least five tsunamis generated by earthquakes and volcanic eruptions along the Sunda Arc have impacted the West Australian coast (1883, 1977, 1994, 2004 and 2006). We have documented the geomorphic effects of these tsunamis through collation of historical reports, collection of eyewitness accounts, analysis of pre- and post-tsunami satellite imagery and field investigations. These tsunamis had flow depths of less than 3 m, inundation distances of up to several hundred metres and a maximum recorded run-up height of 8 m. Geomorphic effects include off-shore and near-shore erosion and extensive vegetation damage. In some cases, vegetated foredunes were severely depleted or completely removed. Gullies and scour pockets up to 1.5 m deep were eroded into topographic highs during tsunami outflow. Eroded sediments were redeposited as sand sheets several centimetres thick. Isolated coral blocks and rocks with oysters attached (~50 cm A-axis) were deposited over coastal dunes however, boulder ridges were often unaffected by tsunami flow. The extent of inundation from the most recent tsunamis can be distinguished as strandlines of coral rubble and rafted vegetation. It is likely that these features are ephemeral and seasonal coastal processes will obscure all traces of these signatures within years to decades. Recently reported evidence for Holocene palaeotsunamis on the West Australian coast suggests significantly larger run-up and inundation than observed from the historical record. The evidence includes signatures such as chevron dunes that have not been observed from historical events. We have compared the geomorphic effects of historical tsunami with reported palaeotsunami evidence from Coral Bay, the Cape Range Peninsula and Port Samson. We conclude that much of the palaeotsunami evidence can be accounted for via more traditional geomorphic processes such as reef evolution, aeolian dune formation and archaeological site formation.

Australian estuaries and coastal waterways were classified into six subclasses according to the wave-, tide- and river-energies that shape them, and also according to their overall geomorphology. The geomorphic classification confirmed the energy classification. Within this framework: - 17% were classified as wave-dominated estuaries; - 11% were classified as tide-dominated estuaries; - 10% were classified as wave-dominated deltas; and - 9% were classified as tide-dominated deltas Therefore, only ~28% of Australian coastal waterways are actually estuaries. The remainder are delta's (19%), strandplains (~5%), or tidal creeks (~35%). A seventh subclass others (13%) includes: Drowned River Valleys, Embayments and Coastal Lakes/Lagoons/Creeks. Strandplains and Tidal Creeks are indicative of very low river-energy, and their joint dominance in the data set (~40%) reflects the fact that Australia is a dry continent, with relatively little river runoff by world standards.

Publicly available bathymetry and geophysical data can be used to map geomorphic features of the Antarctic continental margin and adjoining ocean basins at scales of 1:1-5 million. These data can also be used to map likely locations for some Vulnerable Marine Ecosystems. Seamounts over a certain size are readily identified and submarine canyons and mid ocean ridge central valleys which harbour hydrothermal vents can be located. Geomorphic features and their properties can be related to major habitat characteristics such as sea floor type (hard versus soft), ice keel scouring, sediment deposition or erosion and current regimes. Where more detailed data are available, shelf geomorphology can be shown to provide a guide to the distribution in the area of the shelf benthic communities recognised by Gutt (2007). The geomorphic mapping method presented here provides a layer to add to benthic bioregionalistion using readily available data.

The Australian exclusive economic zone (EEZ) contains1.6 million km2 of submarine plateaus, equal to about 13.8% of the world's known inventory of these features. This disproportionate occurrence of plateaus presents Australia with an increased global responsibility to understand and protect the benthic habitats and associated ecosystems. This special volume presents the results of two major marine surveys carried out on the Lord Howe Rise plateau during 2003 and 2007, during which benthic biological and geological samples, underwater photographs, video and multibean sonar bathymetry data were collected. The benthic habitats present on Lord Howe Rise include hard/rocky substrates covering a small area of volcanic peaks (around 31 km2) and parts of other larger seamounts (eg. the Lord Howe Island seamount) which support rich and abundant epifaunal assemblages dominated by suspension feeding invertebrates. These habitats appear to qualify as ecologically and biologically significant areas under the United Nations Convention on Biological Diversity (CBD) scientific selection criterion 1 (uniqueness or rarity), 4 (vulnerability, fragility, sensitivity or slow recovery) and 7 (naturalness). The collection of papers included in this special volume represents a major advance in knowledge about benthic habitats of the Lord Howe Rise, but also about the ecology of plateaus in general.