Geochemical analysis method XRD

Preparation

Dried samples were disaggregated by passing through a 400-µcm sieve and lightly pressed into back-loaded sample mounts. Samples were analyzed on a PANalytical X'Pert PRO Materials Research Diffractometer using Cu Kα radiation to collect digital data continuously from 3° to 70° 2θ (scan speed = 0.0567° 2θ per second). PANalytical HighScore Plus software version 2.2a was used for pattern processing, mineral phase identification, and Rietveld quantitative mineral analysis.

Database fields pertinent to XRD

quartz
Mineral: quartz
Units: wt. %
Description: Quartz, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
total K-feldspar
Mineral: total K-feldspar
Units: wt. %
Description: Total potassium feldspar, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
total plagioclase
Mineral: total plagioclase
Units: wt. %
Description: Total plagioclase, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
total feldspars
Mineral: total feldspars
Units: wt. %
Description: Total feldspar, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
total 14Å clays
Mineral: total 14Å clays
Units: wt. %
Description: Total 14Å clays, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
total 10Å clays
Mineral: total 10Å clays
Units: wt. %
Description: Total 10Å clays, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
kaolinite
Mineral: kaolinite
Units: wt. %
Description: Kaolinite, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
total clays
Mineral: total clays
Units: wt. %
Description: Total clays, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
gibbsite
Mineral: gibbsite
Units: wt. %
Description: Gibbsite, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
calcite
Mineral: calcite
Units: wt. %
Description: Calcite, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
dolomite
Mineral: dolomite
Units: wt. %
Description: Dolomite, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
aragonite
Mineral: aragonite
Units: wt. %
Description: Aragonite, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
total carbonate
Mineral: total carbonate
Units: wt. %
Description: Total carbonates, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
analcime
Mineral: analcime
Units: wt. %
Description: Analcime, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
heulandite
Mineral: heulandite
Units: wt. %
Description: Heulandite, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
total zeolites
Mineral: total zeolites
Units: wt. %
Description: Total zeolites, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
gypsum
Mineral: gypsum
Units: wt. %
Description: Gypsum, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
talc
Mineral: talc
Units: wt. %
Description: Talc, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
hornblende
Mineral: hornblende
Units: wt. %
Description: Hornblende and related amphiboles, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
serpentine
Mineral: serpentine
Units: wt. %
Description: Serpentine, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
hematite
Mineral: hematite
Units: wt. %
Description: Hematite, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
goethite
Mineral: goethite
Units: wt. %
Description: Goethite, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
pyroxenes
Mineral: pyroxenes
Units: wt. %
Description: Pyroxene, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
pyrite
Mineral: pyrite
Units: wt. %
Description: Pyrite, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
other minerals
Mineral: other minerals
Units: wt. %
Description: Other mineral phase(s), in percent by weight (wt.%), that were detected occasionally, determined from the interpretation of the XRD scan.
amorphous material
Mineral: amorphous material
Units: wt. %
Description: Amorphous, in percent by weight (wt.%), determined from the interpretation of the XRD scan.
inorganic carbon
Mineral: inorganic carbon
Units: wt. %
Description: Inorganic carbon (C) concentration, in percent by weight (wt.%), reported as the result of stoichiometric calculation of carbon present in calcite, dolomite, and/or aragonite as determined by X-ray diffraction (XRD). The formula used was ((Calcite * 0.12)+(Dolomite * 0.1304)+(Aragon * 0.12)). Calculated values for a very small percentage of samples (less than 0.025%) were lower than 0 and are reported as N.D. (non-detect). Precision of one decimal place.