Forbes (SI5507) Depth to bedrock 1:250 000 scale Map - 1st Edition

Created 17/10/2025

Updated 17/10/2025

The image and contours show the depth to slightly weathered bedrock. In many areas, for instance in the deep palaeovalleys of the Lachlan River and Bland and Goobang Creeks, this is most probably broadly equivalent to the depth of transported sediment cover. However, from the drill hole logs available, it is generally not possible to distinguish between transported material and highly weathered saprolite. It is therefore difficult in some areas to estimate the thickness of transported versus in situ regolith material. The model of depth to slightly weathered bedrock is derived primarily from the NSW Department of Land and Water Conservation database of almost 2000 water bores drilled on the Forbes 1:250,000 sheet. These drill holes were supplemented with point and contour data from over 300 mineral exploration industry drill holes. The model was also constrained by the boundaries of outcropping bedrock, and by known and inferred palaeochannel locations interpreted largely from seismic and aeromagnetic surveys. The data were gridded using the TOPOGRID module of ESRI's Arc/Info software, which is based on the ANUDEM program developed by M. Hutchinson ("A new procedure for gridding elevation and stream line data with automatic removal of spurious pits", Journal of Hydrology, 106, 211-232, 1989).

Files and APIs

Tags

Additional Info

Field Value
Title Forbes (SI5507) Depth to bedrock 1:250 000 scale Map - 1st Edition
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/86da9b4c-b471-4338-b37d-f63a91c8ae85
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period
Geospatial Coverage
Map data © OpenStreetMap contributors
{
  "coordinates": [
    [
      [
        147.0,
        -34.0
      ],
      [
        148.5,
        -34.0
      ],
      [
        148.5,
        -33.0
      ],
      [
        147.0,
        -33.0
      ],
      [
        147.0,
        -34.0
      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "Forbes (SI5507) Depth to bedrock 1:250 000 scale Map - 1st Edition". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/forbes-si5507-depth-to-bedrock-1-250-000-scale-map-1st-edition