Open AccessHeat Flow Measurements in a Low Radioactivity Area of the Western Australian Pre‐Cambrian Shield
Author(s) -
Hyndman R. D.,
Everett J. E.
Publication year - 1967
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1967.tb06267.x
Subject(s) - shield , crust , heat flow , geology , heat flux , borehole , mantle (geology) , flux (metallurgy) , geophysics , geomorphology , environmental science , heat transfer , petrology , mechanics , thermal , geotechnical engineering , physics , meteorology , chemistry , organic chemistry
Summary Two measurements in basic low radioactivity rocks on the Pre‐Cambrian Shield of Western Australia give heat flows of 0.69 and 0.82 μcal/cm 2 s. The very low heat flows suggest that the crust in these areas is very depleted in radioactive elements and that the heat flux from the mantle is probably less than 0.4 μcal/cm 2 s. Anomalously low temperature gradients appear in the top 50 to 200 m of the measured boreholes. This behaviour is shown to be common and is explained in terms of an increase in mean surface temperature 50 to 100 years before the measurements, caused by a clearing or burning of the bush and tree cover.