Abstract

In company with the other components and continental successors of the Neoproterozoic to Mesozoic Gondwanaland supercontinent, Phanerozoic Australia has a buoyant cratonic platform characterised by non-marine facies, in contrast to the marine facies of the components of depressed Laurasia. As a supercontinent, Gondwanaland lasted much longer than Laurasia, and was therefore hotter from its more effective insulation of internal heat. Moreover, the Pan-African orogenic cycle, confined to Gondwanaland, augmented the heat supply, and I postulate that Pan-African heat generated a permanently buoyant lower crust by mafic underplating. A crustal layer in the Australian Proterozoic shield with subhorizontal reflectors and velocity (Vp) > 7.5 km s-1 is interpreted as the product of mafic underplating beneath latest Neoproterozoic flood basalt. The Pan-African terrane in East Africa also contains evidence of mafic underplating, and most of Gondwanaland (but not Laurasia) was affected by terminal Pan-African (0.5 Ga) uplift and cooling. In equivalent Late Cretaceous and Late Ordovician stages of the 400 m.y. Pangean supercycle, the Australian (and possibly the South American) platform deviated from the global norm by rising faster than eustatic sea level. In Australia, plate boundary events - steeper subduction, mafic underplating of a lower plate along a divergent back-arc boundary - explain uplift in the east, but not that in the west, which relaxed to its natural buoyant state.
Google map showing geographic bounding box with values North bound East bound West bound South bound
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Product Type/Sub Type

nonGeographicDataset

Constraints

Creative Commons Attribution 4.0 International Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Date (publication)

1997-01-01T00:00:00

Product Type

nonGeographicDataset

Topic Category

geoscientificInformation

GA Catalogue Number

81482 Product http://www.ga.gov.au/metadata-gateway/metadata/record/81482/

Keywords

GA Publication
Journal
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Lineage

Unknown

Digital Transfer Options

onLine

Distributor

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

Source Description

Source data not available.

Metadata File Identifier

fae9173a-71a7-71e4-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 SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
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