Craig's seeps is a wonderful example of scientific work.

There is growing global concern for the impact of increased fluvial sediment loads on tropical coral reefs and seagrass ecosystems. The Fitzroy River is a macrotidal, tide-dominated estuary in the dry tropics of central Queensland and is a major contributor of sediment to the southern Great Barrier Reef (GBR) lagoon. The estuary currently receives most of its sediment during large episodic flood events commonly associated with cyclonic depressions. The sediment dynamics of macrotidal estuaries and especially of wet-dry tropical systems, with intermittent flows and sediment discharge are poorly understood. Average annual sediment budgets for such a system are also difficult to estimate due to the sporadic nature of flood discharge events. Therefore we have estimated a long-term sediment accumulation rate of catchment-derived sediment trapped in the estuary using the Holocene stratigraphic sequence, determined from a series of sediment cores, dated with radiocarbon and optically stimulated luminescence (OSL), and integrated with industry borehole data. We estimate that 17,400 million tonnes (Mt) of river sediment has accumulated in the estuary during the last 8000 years. This suggests a minimum mean annual bulk sediment discharge of the Fitzroy River of 2000 kt yr-1. This estimated 2175 kilotonnes per year (kt yr-1) of bulk sediment is equivalent to 25% of the estimated average annual modern bulk sediment discharge of the Fitzroy River of 8800 kt yr-1, (Kelly and Wong, 1996) suggesting that the sediment trapping efficiency of the Fitzroy estuary during the Holocene has been approximately 25%. This implies that 75% of the river sediment has been exported from the estuary into Keppel Bay and the adjacent GBR lagoon during the Holocene. With minimal accommodation space left in the floodplain, modern sediment accumulation appears to be focussed around the mangroves and tidal creeks, which cover an area of 130 km2. Cores from the tidal creeks were dated using 137Cs, excess 210Pb, and OSL and display sedimentation rates of approximately 1.5 cm yr-1 for the last 45-120 years, or 1700 kt yr-1, and suggest a modern sediment trapping efficiency for the estuary of around 19%. These results provide useful insights into the long-term sedimentation and quantification of the sediment trapping efficiency of a subtropical macro-tidal estuary with episodic floods, where sediment trapping will vary seasonally and inter-annually.

The collection consists of seabed samples collected by Geoscience Australia and other organizations since the 1950s. Samples consist of various shallow cores types, rocks derived from dredging, and sea bed sediments collected by grab and dredge methods. A large proportion of samples are refrigerated.

This dataset provides the spatially continuous data of seabed mud content (sediment fraction < 63 µm) expressed as a weight percentage ranging from 0 to 100%, presented in 0.01 decimal degree resolution raster format. The dataset covers the Australian continental EEZ, including seabed surrounding Tasmania. It does not include areas surrounding Macquarie Island, and the Australian Territories of Norfolk Island, Christmas Island, and Cocos (Keeling) Islands or Australia's marine jurisdiction off of the Territory of Heard and McDonald Islands and the Australian Antarctic Territory. This dataset supersedes previous predictions of sediment mud content for the Australian Margin with demonstrated improvements in accuracy. Accuracy of predictions varies based on density of underlying data and level of seabed complexity. Artefacts occur in this dataset as a result of insufficient samples in relevant regions. This dataset is intended for use at national and regional scales. The dataset may not be appropriate for use at local scales in areas where sample density is insufficient to detect local variation in sediment properties. To obtain the most accurate interpretation of sediment distribution in these areas, it is recommended that additional samples be collected and interpolations updated.

Geoscience Australia carried out a marine survey on Carnarvon shelf (WA) in 2008 (SOL4769) to map seabed bathymetry and characterise benthic environments through co-located sampling of surface sediments and infauna, observation of benthic habitats using underwater towed video and stills photography, and measurement of ocean tides and wave-generated currents. Data and samples were acquired using the Australian Institute of Marine Science (AIMS) Research Vessel Solander. Bathymetric mapping, sampling and video transects were completed in three survey areas that extended seaward from Ningaloo Reef to the shelf edge, including: Mandu Creek (80 sq km); Point Cloates (281 sq km), and; Gnaraloo (321 sq km). Additional bathymetric mapping (but no sampling or video) was completed between Mandu creek and Point Cloates, covering 277 sq km and north of Mandu Creek, covering 79 sq km. Two oceanographic moorings were deployed in the Point Cloates survey area. The survey also mapped and sampled an area to the northeast of the Muiron Islands covering 52 sq km. Seabed sediment samples were collected by a Smith McIntyre grab at a total of 275 locations, divided between Mandu Creek (n=81), Point Cloates (n=92), Gnaraloo (n=92) and Muiron Islands (n=10). The full sample set represents 102 sampling stations at which two sediment grabs were collected in close proximity. The exception to this was at Mandu Creek where three grabs were collected at 19 stations and at Gnaraloo where single grabs were taken at three stations. At Muiron Islands, single grabs were collected at five stations and two grabs at three stations (see Brooke et al. 2009).

There is growing global concern for the impact of increased fluvial sediment loads on tropical coral reefs and seagrass ecosystems. The Fitzroy River is a macrotidal, tide-dominated estuary in the dry tropics of central Queensland and is a major contributor of sediment to the southern Great Barrier Reef (GBR) lagoon. The estuary currently receives most of its sediment during large episodic flood events commonly associated with cyclonic depressions. The sediment dynamics of macrotidal estuaries and especially of wet-dry tropical systems, with intermittent flows and sediment discharge are poorly understood. Average annual sediment budgets for such a system are also difficult to estimate due to the sporadic nature of flood discharge events. Therefore we have estimated a long-term sediment accumulation rate of catchment-derived sediment trapped in the estuary using the Holocene stratigraphic sequence, determined from a series of sediment cores, dated with radiocarbon and optically stimulated luminescence (OSL), and integrated with industry borehole data. We estimate that 17,400 million tonnes (Mt) of river sediment has accumulated in the estuary during the last 8000 years. This suggests a minimum mean annual bulk sediment discharge of the Fitzroy River of 2000 kt yr-1. This estimated 2175 kilotonnes per year (kt yr-1) of bulk sediment is equivalent to 25% of the estimated average annual modern bulk sediment discharge of the Fitzroy River of 8800 kt yr-1, (Kelly and Wong, 1996) suggesting that the sediment trapping efficiency of the Fitzroy estuary during the Holocene has been approximately 25%. This implies that 75% of the river sediment has been exported from the estuary into Keppel Bay and the adjacent GBR lagoon during the Holocene. With minimal accommodation space left in the floodplain, modern sediment accumulation appears to be focussed around the mangroves and tidal creeks, which cover an area of 130 km2. Cores from the tidal creeks were dated using 137Cs, excess 210Pb, and OSL and display sedimentation rates of approximately 1.5 cm yr-1 for the last 45-120 years, or 1700 kt yr-1, and suggest a modern sediment trapping efficiency for the estuary of around 19%. These results provide useful insights into the long-term sedimentation and quantification of the sediment trapping efficiency of a subtropical macro-tidal estuary with episodic floods, where sediment trapping will vary seasonally and inter-annually.

Seismic reflection data show the existence of two major sedimentary basins along the continental margin of Wilkes Land and Terre Adélie, East Antarctica, that contain more than 5 s TWT (> 9 km) of sediments. Four seismic megasequences are identified (MS4 to MS1) that are bounded by: basement, unconformities of interpreted Turonian, Maastrichtian and early Middle Eocene age, and the seafloor. The 4-5 km thick rift and pre-rift sediments are concentrated in a margin-parallel basin (Sabrina Basin). On the basis of seismic correlation with the Australian margin, this basin is interpreted to be of Late Jurassic to mid-Cretaceous age. The post-rift sediments are generally thick along the margin and in the adjacent deep-ocean basin, but are particularly thick in a major depocentre off west Wilkes Land, named here the Budd Coast Basin (BCB). The BCB contains a maximum observed thickness of 5 s TWT (9 km) of post-rift sediments and its location suggests that the sediments were largely derived from a sub-glacial basin currently occupied by the Totten Glacier.

Two facies models are proposed to explain siliciclastic and carbonate depositional systems of 1800 Ma to 1640 Ma age in the Western Fold Belt of the Mt Isa Inlier. Both models record the response of depositional systems to storm-driven processes of sediment transport, dispersal and deposition on a shallow water shelf. The same suite of facies belts can also be identified in sedimentary successions of the Eastern Fold Belt. Slope driven processes of sediment transport and dispersal characterise turbidite and debrite deposits of the Soldiers Cap Group and Kuridala Formation and provide evidence for significantly greater water depths in this part of the basin from ~1685 Ma. Through the recognition of unconformity surfaces, their correlative conformities, maximum flooding and ravinement surfaces the facies belts are packaged into 7 supersequences for the interval 1800-1640 Ma. The new correlations are shown in an Event Chart that correlates linked depositional systems across the entire Mt Isa Inlier. Thick successions of turbidite and debrite deposits are restricted to the eastern parts of the Mt Isa Inlier and do not occur in the Western Fold Belt. A major phase of extension and rifting commenced at ~1740 Ma and by ~1690 Ma led to significant crustal thinning and increased rates of accommodation over an area east of the Selwyn Fault and Burke River Structural Belt. In the Mitakoodi and Selwyn Blocks the rapid transition from shallow water shelf depositional systems of the Prize Supersequence to significantly deeper water slope environments of the Gun Supersequence coincided with the development of a platform margin, the deposition of turbidite and debrite deposits in deep water on the continental slope and the intrusion of mafic sills and dykes. Turbidite and debrite depositional systems of the Soldiers Cap Group and Kuridala Formations are restricted to a lowstand wedge of siliciclastic facies deposited basinward of a platform margin. Basin geometries and sediment architectures associated with this extensional event and recorded in the Gun Supersequence (~1685 Ma to 1650 Ma) provide an explanation for the geographic separation and fluid evolution pathways responsible for the Mt Isa Type and Broken Hill Type Zn-Pb-Ag deposits.

The Fitzroy catchment is the largest Queensland catchment discharging to the Great Barrier Reef (GBR) lagoon. Sediments and nutrients together with anthropogenic pollutants originating upstream in the catchment are discharged from the Fitzroy River via the Fitzroy Estuary (FE) and ultimately into Keppel Bay (KB). The estuary and the bay act as natural chemical reactors where the materials delivered undergo chemical and physical transformations before some are deposited and stored in the growing deltaic and beach areas, with the remainder transported eastward to the southern zone of the GBR lagoon.

The Lower Darling Valley (LDV) Cenozoic sequence contains Paleogene and Neogene shallow marine and shoreline as well as fluvial and shoreline sediments overlain by Quaternary lacustrine, aeolian and fluvial units. Recent investigations in the LDV using multiple datasets have provided new insights into the nature of post-Blanchetown Clay Quaternary fluvial deposition which differs to the Mallee and Riverine Plain regions elsewhere in the Murray Basin. In the LDV Quaternary fluvial sequence, multiple scroll-plain tracts are incised into higher, older and more featureless floodplain terrain. Prior to this study, these were respectively correlated to the Coonambidgal and Shepparton Formations of the Riverine Plain in the eastern Murray Basin. These formations were originally associated with the subsequently discarded Prior Stream/Ancestral River chronosequence of different climatically controlled depositional styles. In contrast to that suggestion, we ascribe all LDV Quaternary fluvial deposition to lateral-migration depositional phases of one style, though with variable stream discharges and channel and meander-scroll dimensions. Successively higher overbank-mud deposition through time obscures scroll traces and provides the main ongoing morphologic difference. A new morphostratigraphic unit, the Menindee Formation, refers to mostly older and higher floodplain sediments, where scroll traces are obscured by overbank mud which continues to be deposited by the highest modern floods. Younger inset scroll-plain tracts, with visible scroll-plain traces, are still referred to as the Coonambidgal Formation. Another new stratigraphic unit, the Willotia beds, refers to even older fluvial sediments, now above modern floodplain levels and mostly covered by aeolian sediments.