Abstract

The Albany Canyon complex off southwest Australia extends 700 km from Cape Leeuwin to east of Esperance. The Canyons head on the uppermost continental slope and extend up to 90 km offshore, to the lowermost slope and onto the abyssal plain. The largest have cut down 1500-2000 m in places. In general, on the upper slope they have cut down into harder, older rocks: Canyon walls are steep, thalwegs slope at up to 15?, and ancient structures control their orientation. On the lower slope the Canyons generally have not reached harder rocks, Canyon walls are less steep, thalweg slopes are less, and they are generally oriented down slope. The Canyons have exposed Jurassic and younger sequences: their nature and information from seismic profiles, have helped us build an understanding of Canyon history. Flood plain deposition rather than erosion occurred during Australia-Antarctic rifting in the Late Jurassic, not supporting cutting of river Canyons. Shallow marine sedimentation characterised the Early Cretaceous, when gradients were low and Canyon cutting unlikely. Deep river Canyons were probably cut during uplift and erosion immediately before the Santonian break-up from Antarctica, and their paths controlled later marine Canyons. Only with the onset of rapid seafloor spreading and subsidence in the Middle Eocene (~43 Ma) did gradients steepen and major marine Canyon cutting become possible. The major sea level fall at the Middle/Late Eocene boundary (~40 Ma) brought sediment to the edge of the continental shelf, which may have initiated the Canyons. Carbonate sedimentation replaced siliciclastic sedimentation in the Late Middle Eocene, but carbonate grains from the outer shelf could cut the Canyons, largely during periods of low sea level.
Google map showing geographic bounding box with values North bound -34.0 East bound 121.0 West bound 117.0 South bound -36.0
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Product Type/Sub Type

dataset - External Publication - Article

Constraints

license
Creative Commons Attribution 3.0 Australia Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2005

Product Type

dataset

Topic Category

geoscientificInformation

Keywords

External Publication
Article
marine
bathymetry
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-34.0
East bound
121.0
West bound
117.0
South bound
-36.0

Lineage

Unknown

Digital Transfer Options

onLine

Distributor

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

Metadata File Identifier

a05f7892-c324-7506-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

2004-08-27

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
Related Links
For information on acquiring this product,
please contact the Geoscience Australia Sales Centre via:

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

Please note that support hours are 9 am to 5 pm weekdays