index mineral

2009 ◽  
pp. 460-460
Keyword(s):  
Index Mineral

EVALUATION OF PROFILE DEVELOPMENT OF SOME SOLONETZIC SOILS OF SOUTH CENTRAL ALBERTA

1976 ◽  
Vol 56 (3) ◽  
pp. 149-158 ◽  
Author(s):  
A. BRUNELLE ◽  
S. PAWLUK ◽  
T. W. PETERS
Keyword(s):  
Particle Size ◽  
High Stability ◽  
Clay Fraction ◽  
Fine Sand ◽  
Size Reduction ◽  
Particle Size Reduction ◽  
Sand Fraction ◽  
South Central ◽  
Gain Reduction ◽  
Index Mineral

The process of solodization was studied with respect to its chemical, physical, and mineralogical aspect and with particular emphasis upon the clay fraction. The net gain or loss of clay occurring in each profile upon solodization was calculated with quartz in the fine sand fraction serving as index mineral. Preferential translocation of montmorillonite over illite was evident in all profiles. K2O content in the total clay fraction indicated that illitization had taken place. For each of three sampling sites, the more solodized members of the sequence of Solonetzic profiles showed a net gain of clay while the least solodized members showed either a deficit or a much smaller gain. Reduction in size of the coarse material (sand size) was evident in most profiles studied. In some profiles, particle size reduction of the sand fraction was accompanied by an increase in clay size quartz in the eluvial horizons which suggests that quartz distribution is to some degree also affected by solodization. Although the use of quartz as an index mineral may therefore not provide an absolute degree of accuracy in quantitative pedology, it was felt that its abundance and its high stability insured useful results.

Loss of zirconium from 12 soils derived from granite

1961 ◽  
Vol 12 (2) ◽  
pp. 300 ◽  
Author(s):  
A Wild
Keyword(s):  
Soil Profiles ◽  
Rock Weathering ◽  
South Wales ◽  
Index Mineral

Analyses are given for zirconium in 12 soil profiles formed from granite in Sew South Wales and Queensland. On the basis that on rock weathering there is no change of volume, it is shown that a loss of zirconium is general in the lower horizons of the profiles and amounts to 20–50% of the rock zirconium. The high losses imply loss of zirconium from grains of zircon. In view of the use of zircon ns an index mineral in soil studies, it is important that the size of zircon grains which are affected should be further investigated.

MINERAL DISTRIBUTION AND WEATHERING IN CHERNOZEMIC AND LUVISOLIC SOILS FROM CENTRAL SASKATCHEWAN

1981 ◽  
Vol 61 (1) ◽  
pp. 79-89 ◽  
Author(s):  
R.J. ST. ARNAUD ◽  
M.D. SUDOM
Keyword(s):  
Glacial Till ◽  
Size Fractions ◽  
Chernozemic Soil ◽  
Lacustrine Deposits ◽  
Mineral Components ◽  
Mineral Compositions ◽  
Mineral Losses ◽  
K Depletion ◽  
Gray Luvisol ◽  
Index Mineral

The quartz, feldspar and mica contents of various fractions from soils developed from both glacial till and lacustrine deposits are compared. Similar mineral compositions are noted for both types of deposits. Using quartz as a resistant index mineral, the degree of weathering of micas, K-feldspars, Na-feldspars, Ca-feldspars, dolomite and calcite are evaluated for an Orthic Black Chernozemic soil and an Orthic Gray Luvisol. The latter soil has been more severely weathered than the Chernozemic soil, showing approximately double the losses of mineral components. Mineral losses from the entire solum of the Gray Luvisol include 40% of the Ca-feldspars, 22% of the Na-feldspars, and 17% of the K-feldspars. Although there is evidence of mica loss within upper horizons of both profiles, the K-depletion in upper layers is balanced by mica increases (K sorption) in lower solum horizons. Possible mechansims of K sorption and desorption among different size fractions are proposed.

scholarly journals The First Occurrence of Asbestiform Magnesio-Riebeckite in Schists in the Frido Unit (Pollino Unesco Global Geopark, Southern Italy)

Fibers ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 79 ◽  
Author(s):  
Salvatore Laurita ◽  
Giovanna Rizzo
Keyword(s):  
Southern Italy ◽  
Analytical Techniques ◽  
X Ray ◽  
Toxicological Studies ◽  
Xrf Scanning ◽  
First Occurrence ◽  
Micro Analysis ◽  
First Time ◽  
Index Mineral

In this paper, new mineralogical and petrographical data of asbestiform Magnesio-riebeckite from ophiolite cropping out in the Pollino Unesco Global Geopark (southern Italy) are presented. Magnesio-riebeckite schists with HP-LT index mineral assemblage recorded metamorphic events in blueschist facies in the Frido Unit. Previous toxicological studies showed that asbestiform Magnesio-riebeckite species exhibited high carcinogenicity in previous intraperitoneal injection experiments with rats. The results have been obtained using different analytical techniques such as X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and electron probe micro analysis (EPMA). Results show that all the samples contain fibrous Magnesio-riebeckite and/or prismatic, acicular crystals in aggregates. The concentration of elements in Magnesio-riebeckite crystals is: Na2O (4.12–6.26 wt%), MgO (8.22–10.87 wt%), FeO (19.07–23.81 wt%), SiO2 (52.05–56.06 wt%), CaO (1.12–4.53 wt%), Al2O3 (1.34–1.93 wt%), and MnO (0.10–0.34 wt%). Magnesio-riebeckite crystals are documented in the Pollino Unesco Global Geopark for the first time. For this reason, the aim of this paper is the characterization of Magnesio-riebeckite to improve the knowledge of this mineral in the studied area, because the release of fibers into the environment is dangerous for human health.

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