Geoscience Australia, ACRES distribute Landsat Multispectral Scanner (MSS), Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) data for a series of epochs or time frames covering Australia. The first epoch is 1972. These data have been produced and provided by the Australian Greenhouse Office (AGO). AGO use the data in their National Carbon Accounting System for monitoring land clearing and revegetation. This data is only available through ACRES and ACRES Landsat Distributors, and not through the AGO. More information is available at <a href="http://www.ga.gov.au/acres/prod_ser/agosuite.jsp">http://www.ga.gov.au/acres/prod_ser/agosuite.jsp</a> This data is available in 1:1M tiles or as a full continental Mosaic. Tiles areas are available at: <a href="http://www.ga.gov.au/acres/prod_ser/agotilemap.jsp">http://www.ga.gov.au/acres/prod_ser/agotilemap.jsp</a>

In the Eastern Lachlan Orogen, the mineralised Molong and Junee-Narromine Volcanic Belts are two structural belts that once formed part of the Ordovician Macquarie Arc, but are now separated by younger Silurian-Devonian strata as well as by Ordovician quartz-rich turbidites. Interpretation of deep seismic reflection and refraction data across and along these belts provides answers to some of the key questions in understanding the evolution of the Eastern Lachlan Orogen-the relationship between coeval Ordovician volcanics and quartz-rich turbidites, and the relationship between separate belts of Ordovician volcanics and the intervening strata. In particular, the data provide evidence for major thrust juxtaposition of the arc rocks and Ordovician quartz-rich turbidites, with Wagga Belt rocks thrust eastward over the arc rocks of the Junee-Narromine Volcanic Belt, and the Adaminaby Group thrust north over arc rocks in the southern part of the Molong Volcanic Belt. The seismic data also provide evidence for regional contraction, especially for crustal-scale deformation in the western part of the Junee-Narromine Volcanic Belt. The data further suggest that this belt and the Ordovician quartz-rich turbidites to the east (Kirribilli Formation) were together thrust over Cambrian-Ordovician rocks of the Jindalee Group and associated rocks along west-dipping inferred faults that belong to a set that characterises the middle crust of the Eastern Lachlan Orogen. The Macquarie Arc was subsequently rifted apart in the Silurian-Devonian, with Ordovician volcanics preserved under the younger troughs and shelves (e.g. Hill End Trough). The Molong Volcanic Belt, in particular, was reworked by major down-to-the-east normal faults that were thrust-reactivated with younger-on-older geometries in the late Early - Middle Devonian and again in the Carboniferous.

A 2-D crustal velocity model has been derived from a 1997 364 km north-south wide-angle seismic profile that passed from Ordovician volcanic and volcaniclastic rocks (Molong Volcanic Belt of the Macquarie Arc) in the north, across the Lachlan Transverse Zone into Ordovician turbidites and Early Devonian intrusive granitoids in the south. The Lachlan Transverse Zone is a proposed west-northwest to east-southeast structural feature in the Eastern Lachlan Orogen and is considered to be a possible early lithospheric feature controlling structural evolution in eastern Australia; its true nature, however, is still contentious. The velocity model highlights significant north to south lateral variations in subsurface crustal architecture in the upper and middle crust. In particular, a higher P-wave velocity (6.24-6.32 km/s) layer identified as metamorphosed arc rocks (sensu lato) in the upper crust under the arc at 5-15 km depth is juxtaposed against Ordovician craton-derived turbidites by an inferred south-dipping fault that marks the southern boundary of the Lachlan Transverse Zone. Near-surface P-wave velocities in the Lachlan Transverse Zone are markedly less than those along other parts of the profile and some of these may be attributed to mid-Miocene volcanic centres. In the middle and lower crust there are poorly defined velocity features that we infer to be related to the Lachlan Transverse Zone. The Moho depth increases from 37 km in the north to 47 km in the south, above an underlying upper mantle with a P-wave velocity of 8.19 km/s. Comparison with velocity layers in the Proterozoic Broken Hill Block supports the inferred presence of Cambrian oceanic mafic volcanics (or an accreted mafic volcanic terrane) as substrate to this part of the Eastern Lachlan Orogen. Overall, the seismic data indicate significant differences in crustal architecture between the northern and southern parts of the profile. The crustal-scale P-wave velocity differences are attributed to the different early crustal evolution processes north and south of the Lachlan Transverse Zone.

ACRES Update Monitoring pastures from space Remote sensing research at Coleambally Irrigation Area Satellite imagery helps to classify Australia's estuaries

Structure and Metamorphic Evolution of Key Areas in the Eastern Fold Belt, Mount Isa Inlier Poster, Mohammad Sayab

The basement beneath Australia's offshore basins was the cradle for sediments involved in oil and gas formation. Knowledge of basement depth, boundaries and evolution provides clues to the petroleum potential of Australia's sedimentary basins. The problem is finding the right combination of geophysical techniques to define basement offshore, and knowing what adjustments to make to reduce unwanted effects in definition. Geoscience Australia's Alexey Goncharov outlines his team's exciting new basement and crustal studies that are tackling the problems.

Product no longer exists, please refer to GeoCat #30413 for the data

Product no longer exists, please refer to GeoCat #30413 for the data

Product no longer exists, please refer to GeoCat #30413 for the data

Product no longer exists, please refer to GeoCat #30413 for the data