Citation

Johnston, S.W. & Petkovic, P., 2011. Offshore Northern Perth Basin 2D and 3D Models of Depth to Magnetic Basement. Record  2012/039. Geoscience Australia, Canberra.

Abstract

During 2009-11 Geoscience Australia completed a petroleum prospectivity study of the offshore northern Perth Basin as part of the Australian Government's Offshore Energy Security Program. A significant component of the program was the acquisition of a regional 2D reflection seismic and potential field survey GA-310 in 2008/09, which has aided in furthering the understanding of basement within the northern Perth Basin. Geologic basement in the northern Perth Basin, defined here to be Precambrian and older, is deep and generally not resolved in the reflection seismic data. However the GA-310 magnetic anomaly data combined with Geoscience Australia's magnetic ship-track database and magnetic anomaly grid allowed an assessment of depth to magnetic sources, and estimation of sediment thickness, providing new insight into basement depth and trends. New magnetic susceptibility measurements taken from core of offshore wells of the northern Perth Basin, seismic interpretation and depth to magnetic source estimates using the magnetic spectral method have been used to constrain 2.5D magnetic forward models. These magnetic models indicate that intrusion of the deepest sediments by high-susceptibility bodies is probable. The reflection seismic evidence for these bodies is not clear, though in some cases they may be associated with faults and structural highs. Where the modelled bodies penetrate the sediments they are mostly below or within the Permian strata. A moderate positive magnetic anomaly along the Turtle Dove Ridge is modelled in 2D by massive bodies whose tops are 5-15 km below sea floor. A depth to magnetic basement map highlights sub-basins and structural highs within the northern Perth Basin, and is shown to be a good first order approximation of sediment thickness and basin geometry. For instance maximum sediment thicknesses of the Abrolhos, Zeewyck and Houtman sub-basins are shown to be 10, 13.5 and 12 km respectively.
Google map showing geographic bounding box with values North bound -23.0 East bound 116.0 West bound 108.0 South bound -31.0
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Product Type/Sub Type

dataset - GA Publication - Record

Constraints

license
Creative Commons Attribution 3.0 Australia Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2011

Product Type

dataset

Topic Category

geoscientificInformation

Keywords

GA Publication
Record
sedimentary basins
magnetics
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-23.0
East bound
116.0
West bound
108.0
South bound
-31.0

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

b0140d6f-15cf-55d6-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

2011-10-25

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 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