Publication
Names
  • C. Vogt
  • J. Lauterjung
  • R. X. Fischer
Title
Investigation of the clay fraction (< 2 µm) of the clay minerals society reference clays
Abstract
We studied a set of 15 reference clays from The Clay Minerals Society (CMS) Source Clays repository. Our aim was to use them as reference materials in our version of the QUAX mineral database. The QUAX software (Quantitative Phase-Analysis with X-ray Powder Diffraction) has been used successfully at the KTB site (German Continental Deep Drillling) to determine mineral assemblages quickly, in an automatic fashion, on a large number of samples (~40,000). It was also applied to Quaternary marine sediments of the Japan Sea. Our current research focuses on marine and lacrustrine sediments from the Arctic Ocean and Siberia. QUAX is a full-pattern method using a reference materials database. The quality of a particular quantification depends on the availability of the relevant mineral phases in the database. Our aim is to extend and improve the database continuously with new data from our current projects, particularly from clay and feldspar minerals. A reference material in the QUAX software must be monomineralic. Before X-ray diffraction (XRD) patterns of CMS clays could be added to the database, quantification of any impurities was necessary. After measuring the bulk material by XRD, the <2 µm fraction was separated because we assumed it would contain the smallest amount of impurities. Here we present grain-size data, XRD data and X-ray fluorescence (XRF) data for this clay-sized fraction. The results of chemical and mineralogical preparation techniques and (elemental) analysis methods were combined. For XRD, random and oriented clayaggregate samples as well as pressed pellets for QUAX analysis were prepared. Semi-quantitative clay mineral determinations were run for comparison.
Keywords
minerals, Smectites, Kaolinite, Palygorskite, Montmorillonite, Hectorite, Mica-Montmorillonite, Beidelite, Illite
Content
material-matter
Year
2001
Journal
Clays and Clay Minerals
Volume
50
Number
3
Pages
388 - 400
Pages number
13
Document type
article
Publication state
published
Comments
contain analysis of Clay Mineral Repository mineral matters