THE MICROMORPHOLOGY AND ELECTRON MICROPROBE ANALYSIS OF TWO RESIDUAL SOILS, ONE DEVELOPED ON GRANITE, THE OTHER ON MARBLE, IN PETERBOROUGH COUNTY, ONTARIO

1972 ◽  
Vol 52 (1) ◽  
pp. 79-89 ◽  
Author(s):  
J. E. GILLESPIE ◽  
R. PROTZ

Micromorphological studies of two residual soils have revealed a constant mineralogy with depth in each soil and maximum cutan development in the B horizon. Electron microprobe analysis has shown iron, titanium, and carbon in all of the cutans. Calcium was present in the cutans around feldspar grains in the Methuen, a soil derived from granite gneiss, but was not present in the cutans around quartz grains. The inner layer of the grain cutans consisted of iron and titanium, the outer layer having in addition silica and aluminum. These latter elements were indicators of clay minerals. Microprobe analysis of mica grains indicated losses of magnesium and potassium from the mica in the A horizons of both soils compared with the levels of these elements present in the mica in the C1 horizons.

1973 ◽  
Vol 53 (4) ◽  
pp. 349-361 ◽  
Author(s):  
R. BREWER ◽  
R. PROTZ ◽  
J. A. McKEAGUE

A number of thin iron–manganese pans from soils with peaty surface horizons have been examined with a light microscope and electron microprobe analyzer. The results show that: (1) concentrations of Fe and Mn (as oxides, hydroxides, or both) occur distinctly separated from each other even where closely associated, i.e., every unit analyzed was dominantly either Mn or Fe with little contamination by the other; (2) Mn concentrations always increase in proportion to Fe with increasing depth in the pans; generally Mn concentrations underlie Fe concentrations; (3) at least in these pans, the various kinds of Fe and Mn concentrations can be distinguished optically by using both transmitted and reflected light characteristics.


Clay Minerals ◽  
1984 ◽  
Vol 19 (2) ◽  
pp. 243-247 ◽  
Author(s):  
B. Velde

The electron microprobe has been used in petrographic research for almost 20 years and more recently as a tool for investigations of clay minerals. However, to the author's knowledge no information has been published concerning the reliability of such analyses―especially those of the alkali elements. Since the alkali contents of clays are often critical, e.g. in determining the smectite content of mixed-layered minerals, it is important to have some idea of the reliability of an analysis made using an electron microprobe.Three variables can be controlled in electron microprobe analysis—time, beam-current intensity and beam size (the diameter of the beam which excites the sample). Exaggerated conditions of any one of these variables tend to diminish the signal received by the detectors for the alkali elements, especially sodium. As an example, the effect of varying two of these parameters on the intensity of sodium radiation for sodium-aluminumsilicon glass is shown in Fig. 1. The signal decreases (% loss Na) over a 200 s counting time. Beam intensity and beam diameter were varied in this example.


1977 ◽  
Vol 14 (8) ◽  
pp. 1740-1752
Author(s):  
Hewitt H. Bostock

The compositions of seven pairs of coexisting hornblende and grunerite and five assemblages of coexisting hornblende, grunerite, and garnet from Archean silicate iron formation of low and medium metamorphic grade have been obtained by electron microprobe analysis. Important factors affecting the composition of the amphiboles are: (1) the Mg/Fe ratio of the iron-formation beds, which controls the gross Mg/Fe ratio of the amphiboles; (2) the alumina content of the beds, which affects the degree of alumina substitution in hornblende thereby altering the distribution of Mg and Fe in the coexisting amphiboles; and (3) the occurrence of iron-rich garnet, which produces higher Mg/Fe ratios in both amphiboles. A fourth potentially important factor, the oxygen fugacity, cannot be satisfactorily assessed with these data, but has not obscured the effects of the other three. Temperature of crystallization of the amphiboles was an important factor mainly insofar as it affected the crystallization of garnet in the alumina-rich rocks.Four coexisting hornblende–cummingtonite pairs from metatuffs show similar control of Mg–Fe fractionation by alumina substitution in hornblende.


Author(s):  
R. I. Johnsson-Hegyeli ◽  
A. F. Hegyeli ◽  
D. K. Landstrom ◽  
W. C. Lane

Last year we reported on the use of reflected light interference microscopy (RLIM) for the direct color photography of the surfaces of living normal and malignant cell cultures without the use of replicas, fixatives, or stains. The surface topography of living cells was found to follow underlying cellular structures such as nuceloli, nuclear membranes, and cytoplasmic organelles, making possible the study of their three-dimensional relationships in time. The technique makes possible the direct examination of cells grown on opaque as well as transparent surfaces. The successful in situ electron microprobe analysis of the elemental composition and distribution within single tissue culture cells was also reported.This paper deals with the parallel and combined use of scanning electron microscopy (SEM) and the two previous techniques in a study of living and fixed cancer cells. All three studies can be carried out consecutively on the same experimental specimens without disturbing the cells or their structural relationships to each other and the surface on which they are grown. KB carcinoma cells were grown on glass coverslips in closed Leighto tubes as previously described. The cultures were photographed alive by means of RLIM, then fixed with a fixative modified from Sabatini, et al (1963).


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