Bayon et al.(2006)による〔『The control of weathering processes on riverine and seawater hafnium isotope ratios』(433p)から〕

『河川および海水のハフニウム同位体比に対する風化過程のコントロール』


Abstract
 Hafnium 176Hf/177Hf isotope ratio variations in marine records are thought to reflect changes in continental weathering through time, but the behavior of Hf in rivers, and during weathering, is not well understood. Here, we present 176Hf/177Hf data for rivers, bedrock, soils, and leaching experiments for the Moselle basin, Vosges, France. These data strongly suggest that the 176Hf/177Hf composition of river waters is controlled by preferential dissolution of accessory phases (i.e., apatite, sphene) versus more resistant minerals (e.g., K-feldspar) and linked to the intensity of silicate weathering. Estimates for the global isotopic composition of riverine Hf suggest that the ocean Hf budget may be dominated by river input, and variations seen in marine records can be directly related to changes in silicate weathering intensity.

Keywords: hafnium isotopes; rivers; silicate weathering; ocean chemistry』

Introduction
Materials and methods
Results
Linking Hf isotopes to silicate weathering processes
 Evidence from partition coefficient ratios
 Evidence from granite leaching experiments
 Evidence from river chemistry
Implications for the ocean Hf budget and the evolution of seawater εHf through time
Acknowledgments
References cited


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