Citation

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Vanden Broek, P.H., 1980. Engineering geology of the proposed Darwin East urban development area, Northern territory. Bulletin  203. Bureau of Mineral Resources, Geology and Geophysics, Canberra.

Abstract

Field mapping, augering, and rotary core drilling have defined the main geological constraints to urban planning in the proposed Darwin East urban development area. The area is underlain by a sequence of subhorizontal Mesozoic rocks unconformably overlying a gently folded sequence of Lower Proterozoic rocks, which include cavernous dolomite. The overlying rocks have in places subsided into the cavernous dolomite to form dolines. A highly plastic clay lining the floor of these dolines has transformed some of them into perennial and ephemeral lagoons. Geomorphological processes have developed four major land surfaces which contain the present-day physiographic features and determine the distribution of the soil types. Of the twelve soil types mapped, planosol and yellow lateritic podzolic soils are expected to be troublesome: they have poor drainage characteristics. The establishment of a piezometer network, and subsequent water-level measurements, indicate that the groundwater catchments for the springs on the southern escarpment are likely to be more extensive than previously thought because the groundwater divide does not correspond to the topographic highs. Of the proposed alternative drainage schemes, a conventional scheme which minimises infiltration is favoured. Some supplementary subsurface drains might have to be installed to effectively drain the ephemeral lagoons and broad flat drainage depressions. Maintenance of the water-levels in the perennial lagoons is preferred to draining them. A plot of earthquake data indicates that nearly all seismic activity originates in the Banda Sea area, north of Australia. A comparison of data recorded from earthquakes in this area since early this century with a more recent Banda Sea earthquake of known felt intensity suggests that an earthquake with a felt intensity of MM V in Darwin can be expected at least once every 50 years. Coarse aggregate is readily available in the area, and resources of fine aggregate, fine sand, gravel, and topsoil may prove to be substantial. Extraction could be integrated with a sanitary method of garbage disposal. Some foundation problems can be expected for large structures sited above subcropping cavernous dolomite or completely weathered mudstone and shale. Planosols in the area have low bearing strengths when they are saturated, but these should not be a problem once urban drains are installed. Excavation for services will be difficult and expensive where quartzite crops out or lies just below the surface. Some sites are worthy of preservation as geological monuments. Rock bars, suitable for the foundation of relatively inexpensive embankments, occur adjacent to East Arm and Elizabeth River. A possible alternative site for an airport, northeast of Knuckeys Lagoon, lies partly within and adjacent to the Darwin East urban development area. Scope exists for the planning of a marina in Hudsons Creek, and for the use of sewerage effluent to irrigate part of the Mitchells Creek catchment.
Google map showing geographic bounding box with values North bound -12.0 East bound 131.5 West bound 130.5 South bound -13.0
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Product Type/Sub Type

dataset - GA Publication - Bulletin

Constraints

license
Creative Commons Attribution 3.0 Australia Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

1980

Product Type

dataset

Topic Category

geoscientificInformation

Keywords

GA Publication
Bulletin
geology
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-12.0
East bound
131.5
West bound
130.5
South bound
-13.0

Lineage

Unknown

Digital Transfer Options

onLine

DISTRIBUTION Format

pdf

Distributor

Role
distributor
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address

Metadata File Identifier

a05f7892-9cfb-7506-e044-00144fdd4fa6

Metadata Standard Name

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Metadata Standard Version

1.1

Metadata Date Stamp

1999-08-03

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
Downloads
For information on acquiring this product,
please contact Geoscience Australia Client Services via:

fax:
+61 2 6249 9960; or
phone:
1800 800 173 (within Australia);
 
+61 2 6249 9966 (outside Australia).