Noncoaxial K-feldspar and AMS subfabrics in the Land's End granite, Cornwall: Evidence of magmatic fabric decoupling during late deformation and matrix crystallization

Abstract

A comparative study of the anisotropy of magnetic susceptibility (AMS) and K-feldspar phenocryst fabrics in the Land’s End Granite demonstrates that the AMS data primarily reflect late late magmatic deformation overprints. A general model of fabric development associated with a vertical pure-shear overprint on a variable vertical fabric is evaluated by numerical modeling.

The study demonstrates how the memory of different fabric elements may be dependent upon their grain size, crystallization sequence and recorded previous strain.

Keywords

• Noncoaxial AMS subfabrics
• Land's End granite
• magmatic fabric