Heat flow and heat production in Australian Proterozoic terranes: The reality of a hot southern continent  


Authors / CoAuthors

McLaren, S. | Sandiford, M. | Hand, M. | Neumann, N. | Wyborn, L.A.I. | Bastrakova, I.V.

Abstract

Available surface heat flow measurements from Australian Proterozoic terranes (83 1 18 mWm-2) are significantly higher than the global Proterozoic average of ~ 50 mWm-2. Seismic evidence for the presence of relatively cool mantle together with the lack of evidence for neotectonic processes normally associated with thermal transients suggests that anomalous heat flow must reflect crustal radiogenic sources (U, Th and K). This is supported by a compilation of > 6000 analyses from ~ 460 individual granites, granitic gneisses and felsic volcanics which shows that the present day average heat production of these rock types is 4.6 ?Wm-3 when normalized by area of outcrop (over more than 100 000 km2); roughly twice that of "average" granite. At the time of this felsic magmatism (ca. 1850-1500 Ma) heat production rates were some 25%-30% greater than the present day such that the total complement of U, Th and K in many parts of the Australian Proterozoic crust may have contributed as much as 60-85 mWm-2 to the surface heat flow, or 2 to 3 times the present day continental average. This extraordinary enrichment has played a key role in the tectono-thermal evolution of the Australian Proterozoic crust.

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nonGeographicDataset

eCat Id

37428

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Commonwealth of Australia (Geoscience Australia)  
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia

Keywords

  • External PublicationScientific Journal Paper
( Theme )
  • geochemistry
( Theme )
  • geophysics
Australian and New Zealand Standard Research Classification (ANZSRC)
  • Earth Sciences
  • Published_Internal

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2001-01-01T00:00:00

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Creative Commons Attribution 4.0 International Licence    

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