Abstract

Refined unit-cell dimensions determined for a suite of perthitic alkali feldspars from a nearsurface plutonic environment were used to construct standard aluminum occupancy plots. From comparison of natural and dry-heated specimens it is apparent that, on heating, aluminum moves from the T1o site into the T1m site faster than into the combined T2o and T2m sites. This suggests a two-step disordering path which is nearly the reverse of the ordering path(s) inferred for igneous and metamorphic Introduction

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.