BY PETER J. SMITH
Department of Earth Sciences
Open University
Milton Keynes, U.K.
" The absence of Hadean sediments at the Earth’s surface need not mean that they were never produced. They could all have been subducted along with the igneous crust after being mixed with dense meteorite impact debris.
A.F.K. van Groos, “Weathering, the carbon cycle, and the differentiation of the continental crust and mantle,” Journal of Geophysical Research, 93 (B8), 8952-8, 10 August 1988
" Dating of Australian Archean crust shows that, locally, greenstones are always older than granites. This leads to a new model for the formation of granite-greenstone terrains in which an asthenospheric thermal anomaly produces greenstones from melted mantle and, with a time lag, granites from melted lower crust.
I.H. Campbell, R.L Hill “A two-stage model for the formation of the granite-greenstone terrains of the Kalgoorlie-Norseman area, Western Australia,” Earth and Planetary Science Letters, ...
