Amino acid racemization (AAR) dating of the eolianite on Lord Howe Island is used to correlate several disparate successions and provides a geochronological framework that ranges from Holocene to Middle Pleistocene time. The reliability of the AAR data is assessed by analysing multiple samples from individual lithostratigraphic units, checking the stratigraphic order of the D/L ratios and the consistency of the relative extents of racemization for a suite of seven amino acids. Three aminozones are defined on the basis of the extent of racemization of amino acids in land snails (Placostylus bivaricosus) and 'whole-rock' eolianite samples. Aminozone A includes Placostylus from modern soil horizons (e.g. mean D/L-leucine ratio of 0.03±0.01) and whole-rock samples from unconsolidated lagoonal and beach deposits (0.10±0.01-0.07±0.03). Aminozone B includes Placostylus (0.45±0.03) and whole-rock samples from beach (0.48±0.01) and dune (0.45±0.02-0.30±0.02) units of the Neds Beach Formation, deposited during OIS 5. The oldest, Aminozone C, comprises Placostylus recovered from paleosols (0.76±0.02) and whole-rock eolianite samples (0.62±0.00) from the Searles Point Formation, which indicate the formation was likely deposited over several Oxygen Isotope Stages (OIS), during and prior to OIS 7. These data support independent lithostratigraphic interpretations and are in broad agreement with U/Th ages of speleothems from the Searles Point Formation and corals from the Neds Beach Formation, and with several TL ages of dune units in both formations. The AAR data reveal that eolianite deposition extends over a significantly longer time interval than previously appreciated and indicate that the deposition of the large dune units is linked to periods of relatively high sea level.

This dataset has been digitised from the 1:25000 vegetation map of Christmas Island (accompanying Mitchells 1985 report). The vector version was completed on behalf of Parks Australia Christmas Island. Geoscience Australia used ArcInfo to heads-up digitise a scanned version of the map. Once digitised the arcs were built into polygons and the map was attributed based on the Geoscience Australia data dictionary guidelines. All information relating to vegetation boundaries was extracted from the map and incorporated in the table. The fields that were used follow: Alias Type Width Decimal -----------------------------------------------Shape FIELD_SHAPEPOLY 80Ufi FIELD_DECIMAL 6 0 - unique numberArea FIELD_DECIMAL 18 5Perimeter FIELD_DECIMAL 18 5Code FIELD_CHAR 80 0 - Vegetation unit (map symbol)Descript FIELD_CHAR 64 0 - Description of unitCategories FIELD_CHAR 50 0 - vegetation categoriesFeature FIELD_CHAR 12 0 - (GA field)Plotrank FIELD_DECIMAL 1 0 - (GA field)

The ANCA directory contains two scanned images, geology.tif and veg.tif. The geology map contains the following information: Base map compiled from topographic base sheets prepared by Australian Aerial Mapping Pty. Ltd. and supplied by The British Phosphate Commissioners. Geology and compilation by J. Barrie 1965-66 Drawn by J. Kopros Bureau of Mineral Resources, Geology and Geophysics CHRISTMAS ISLAND SURVEY 1965-66. To accompany Record 1967/37. The vegetation map contains the following message: Vegetation map - Accompanies Mitchells 1985 Report. ONLY COPY!! See File 80/13 for Report. It is based on J Barries geology map.

Exploration fundamentals related to predicted world economic growth and higher oil prices suggest a resurgence in exploration for oil and gas liquids in the Timor Sea in the next two years, despite a slow down in exploration drilling in the last 12 months.

This document describes a format of the AVNIR-2 (Advanced Bisible Near-Infrared Radiometer) products generaged by the ALOS Data Processing Subsystem.

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

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

This dataset contains polygons that bound parts of Irvine Hill forest. The polygons were constructed by drawing lines that join points which were pegged out as being boundaries of the Irvine Hill area. The main points were supplied by Whelans. The line joins and polygon making process was done by Geoscience Australia. The shapefile containing the data is: forestedge_irvineh.shp. Details of the fields can be seen below: Field Type Width Decimal---------------------------------------------------Shape FIELD_SHAPEPOLY 8 0Area FIELD_DECIMAL 12 3Perimeter FIELD_DECIMAL 12 3Plot3pef2_ FIELD_DECIMAL 11 0Plot3pef2_ FIELD_DECIMAL 11 0Entity FIELD_CHAR 14 0Layer FIELD_CHAR 32 0Elevation FIELD_DECIMAL 18 5Thickness FIELD_DECIMAL 18 5Color FIELD_DECIMAL 11 0Pointnumbe FIELD_DECIMAL 11 0Pointheigh FIELD_DECIMAL 18 5Pointcode FIELD_CHAR 8 0Sourcethm FIELD_CHAR 16 0Hectares FIELD_DECIMAL 16 3

A useful spin off of the soft photogrammetry is the opportunity to get one metre contours over the disturbed areas of the Island. For the north-east area of the Island 2km X 2km DEM contour tiles have been trialed in the CIGIS. Most are at a contour interval of 5 metres but tiles 2269 and 2469 have been done at a one metre contour interval. The DEM contours are surface contours. They pick up the reflective surface beneath the aircraft. The reflective surface may be the ground or it may be a dense vegetation canopy or rooftops etc. Further one metre contour coverage can be prepared on a cost recovered basis.

Lithostratigraphy, grain sizes and down-hole logs of Site 1166 on the continental shelf, and Site 1167 on the upper slope, are analyzed to reconstruct glacial processes in eastern Prydz Bay and the development of the Prydz trough-mouth fan. In eastern Prydz Bay upper Pliocene-lower Pleistocene glaciomarine sediments occur interbedded with open-marine muds and grade upward into waterlaid tills and subglacial tills. Lower Pleistocene sediments of the trough-mouth fan consist of coarse-grained debrites interbedded with bottom-current deposits and hemipelagic muds, indicating repeated advances and retreats of the Lambert Glacier-Amery Ice Shelf system with respect to the shelf break. Systematic fluctuations in lithofacies and down-hole logs characterize the upper Pliocene-lower Pleistocene transition at Sites 1166 and 1167 and indicate that an ice stream advanced and retreated within the Prydz Channel until the mid Pleistocene. The record from Site 1167 shows that the grounding line of the Lambert Glacier did not extend to the shelf break after 0.78 Ma. Published ice-rafted debris records in the Southern Ocean show peak abundances in the Pliocene and the early Pleistocene, suggesting a link between the nature of the glacial drainage system as recorded by the trough-mouth fans and increased delivery of ice-rafted debris to the Southern Ocean.