CRC LEME
Open File Report 157:
ABSTRACT
Teilta regolith project: Basement modelling
L. Ruperto
The basement modelling research initiative, which is part of
the Teilta regolith project of CRC LEME Project 2.1, involved
the development and construction of a 3D depth to basement model
over the area covered by the Teilta 1:100,000 topographic map
sheet. This arid landscape, located just to the north of the Broken
Hill Domain, is dominated by Proterozoic bedrock overlain by various
regolith units. The 3D model is able to provide a visual insight
into the form and nature of the subsurface environment, in particular
visualising the subsurface configuration of the Palaeoproterozoic
Willyama basement under cover. The data used for this project,
although forming a relatively small dataset, was collected from
two major sources: (1) drillhole intersections as collated by
New South Wales Department of Mineral Resources, and (2) ground
observations of bedrock outcrops collated by Steve Hill from Adelaide
University. Following a number of spatial adjustments required
to fit the data to the topography, a variety of GIS products (such
as contours maps, interpolated grids, point datasets) were generated
and form the foundations of the 3D depth to basement model. The
model allows for visualisation of the topographic surface combined
with the interpreted location of the basement as it would appear
in the actual environment in three dimensions. This allows the
viewer to examine the model in a full 360° range of motion,
including enabled zoom in/out features. The 3D model is able to
identify areas where bedrock crops out at the topographic surface
or where it is only very shallow below that surface, while also
displaying significantly deeper bedrock distribution within the
map sheet area.
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