Format

Send to

Choose Destination
Science. 2012 Mar 16;335(6074):1334-6. doi: 10.1126/science.1216066.

A change in the geodynamics of continental growth 3 billion years ago.

Author information

1
Department of Earth Sciences, University of St. Andrews, St. Andrews, UK. b.dhuime@bristol.ac.uk

Abstract

Models for the growth of continental crust rely on knowing the balance between the generation of new crust and the reworking of old crust throughout Earth's history. The oxygen isotopic composition of zircons, for which uranium-lead and hafnium isotopic data provide age constraints, is a key archive of crustal reworking. We identified systematic variations in hafnium and oxygen isotopes in zircons of different ages that reveal the relative proportions of reworked crust and of new crust through time. Growth of continental crust appears to have been a continuous process, albeit at variable rates. A marked decrease in the rate of crustal growth at ~3 billion years ago may be linked to the onset of subduction-driven plate tectonics.

PMID:
22422979
DOI:
10.1126/science.1216066
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center