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A Change in the Geodynamics of Continental Growth 3 Billion Years Ago

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Science  16 Mar 2012:
Vol. 335, Issue 6074, pp. 1334-1336
DOI: 10.1126/science.1216066

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Continental Growth Spurts

The appearance and persistence of continents through geologic time has influenced most processes on Earth, from the evolution of new species to the climate. The relative proportion of newly formed crust compared to reworked, or destroyed, older crust reveals which processes controlled continental growth. Based on the combined analyses of Hf-Pb and O isotopes in zircon minerals, Dhuime et al. (p. 1334) measured continuous but variable rates of new crustal production throughout Earth's history. Increased rates of crustal destruction starting around 3 billion years ago coincide with the onset of subduction-drive plate tectonics, slowing down the overall rate of crustal growth.

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