Assessing volumetric strains and mass balance relationships resulting from biotite-controlled weathering: Implications for the isovolumetric weathering of the Boulder Creek Granodiorite, Boulder County, Colorado, USA

Auteur(s) et Affiliation(s)



Description :
The AA. present results from a study of two sites located on the 1.65 Ga Boulder Creek Granodiorite near Boulder, Colorado, USA, in which weakly chemically altered saprock derived from tonalitic and granodioritic–tonalitic bedrock records volumetric strains on the order of 7.6%–8.5% and 7.9%–8.2% respectively. They show that dilation is likely due to the alteration of biotite to vermiculite during the early stages of weathering, and is associated with an expansion normal to the {001} cleavage of ~ 40%. Theoretical calculations of volumetric strains based on the modal biotite present in the protolith support such an interpretation.


Type de document :
Article de périodique

Source :
Catena (Giessen), issn : 0341-8162, 2014, vol. 120, p. 29-45, nombre de pages : 17, Références bibliographiques : 1 p.

Date :
2014

Editeur :
Pays édition : Allemagne, Cremlingen-Destedt, Catena