Continental igneous rock composition: A major control of past global chemical weathering.

ABSTRACT: The composition of igneous rocks in the continental crust has changed throughout Earth's history. However, the impact of these compositional variations on chemical weathering, and by extension on seawater and atmosphere evolution, is largely unknown. We use the strontium isotope ratio in seawater [(⁸⁷Sr/⁸⁶Sr)_seawater] as a proxy for chemical weathering, and we test the sensitivity of (⁸⁷Sr/⁸⁶Sr)_seawater variations to the strontium isotopic composition (⁸⁷Sr/⁸⁶Sr) in igneous rocks generated through time. We demonstrate that the ⁸⁷Sr/⁸⁶Sr ratio in igneous rocks is correlated to the epsilon hafnium (εHf) of their hosted zircon grains, and we use the detrital zircon record to reconstru

SUBMITTER: Bataille CP 

PROVIDER: S-EPMC5342656 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature