Titanite low-temperature alteration and Ti mobility

Date

2005

Authors

Tilley, David
Eggleton, Richard

Journal Title

Journal ISSN

Volume Title

Publisher

Clay Minerals Society

Abstract

A pseudomorphous aggregate after titanite composed of smectite, anatase and residual titanite of composition (Ca0.98,Mn0.02)(Ti0.65,Al0.35)[SiO4](O0.65,OH0.35), from a depth of 450 m in the Broken Hill South Mine, New South Wales, Australia, was investigated by electron microscopy and microanalysis to characterize the alteration products and the mobility of Ti. Examination of the pseudomorph showed randomly oriented anatase crystals dispersed throughout a matrix of beidellite, with 9% porosity. Around the periphery and along the (110) cleavage plane of titanite, alteration was most developed. The range of Ti mobility was found to be limited to ∼500 nm, and the ratio between the average diameter of anatase crystals and the average distance between them is ∼1.3. This ratio is consistent with an alteration process in which Ti is conserved and the anatase crystals grow from the Ti available immediately around them. It is unlikely that Ti migrated beyond the titanite pseudomorph.

Description

Keywords

Keywords: Aggregates; Crystal growth; Crystals; Porosity; Titanium compounds; Transmission electron microscopy; Anatase crystals; Beidellite; Low temperature alteration; Titanite; Clay minerals; mineral alteration; titanite; Pseudomorpha Aluminous titanite; Anatase; Beidellite; Mobility; Montmorillonite; Smectite; Sphene; Titanium

Citation

Source

Clays and Clay Minerals

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1346/CCMN.2005.0530110

Restricted until

2037-12-31