A. Gillhaus et al., Quantitative high resolution cathodoluminescence spectroscopy of diagenetic and hydrothermal dolomites, SEDIMENT GE, 140(3-4), 2001, pp. 191-199
A combination of high resolution cathodeluminescence-spectroscopy (HRS-CL =
high resolution spectroscopy of cathodoluminescence emission) with spatial
resolving trace element analyses (PIXE = proton induced X-ray emission) is
used to establish a method for the quantitative determination of the Mn-co
ntent of diagenetic and hydrothermal dolomites using the measurements of pe
ak areas of Mn-activated CL emission bands. This method takes into account
the overlap of the CL broad bands of Mn2+ in the Mg- and the Ca-lattice-pos
ition of dolomite. There is a linear correlation between the peak areas and
Mn concentration up to approx. 1000-1500 ppm. Thus. CL spectroscopy allows
a determination of Mn concentrations below the abilities of PIXE (10-15 pp
m) to less than 1 ppm by extrapolation of this linear relation.
Up to an Fe-content of approx. 2000 ppm, no quenching effect of Fe on this
linear relationship occurs. However, Fe-contents above 2000 ppm result in a
decrease of Mn-induced luminescence. Even at Fe-concentration > 25,000 ppm
spectroscopy reveals that Mn-activated CL of dolomite is not entirely exti
nguished. (C) 2001 Elsevier Science B.V. All rights reserved.