Glomerocrysts: Textural Evidence for Mineral Resorption during Crystallization of Igneous Rocks.
The Digdeguash-Flume Ridge transition on the eastern flank of the Fredericton trough is marked by four significant changes: a rapid shift from non-calcareous to at least slightly calcareous sandstone; a decrease in grain size of the coarsest beds from granules and coarse sand to fine sand and silt; a sharp decrease in the amount of pelite (aluminous slate in D and E horizons of Digdeguash Bouma sequences is replaced by quartzofeldspathic siltstone in the Flume Ridge); and an increase in clast maturity of the coarse fraction, with typical sand-to granule-sized lithic fragments in the Digdeguash mostly giving way to monomineralic
quartz and feldspar grains in the Flume Ridge.
Objective: The worlds greatest resources of platinum-group elements, Cr and V are found in almost monomineralic
, metre-scale, layers of Cr- and Fe-Ti oxides that formed during solidification of large bodies of basaltic magma trapped in the Earths crust (i.
character of each grain is proven by its electron diffraction pattern, checking the existence of a single network and, therefore, a single crystalline phase.
The most efficient separation techniques operate on monomineralic
particles obtained after crushing and grinding, but obviously this ideal situation can hardly be achieved and most often multiphasic or so-called unliberated particles are present in the process.
The highest grade, nearly monomineralic
brucite deposits are found in aureoles where the protolith consists of magnesite with little or no calcite, clays, chert or other mineral impurities.
Although the thermal conductivity in monomineralic
systems is mainly controlled by porosity and the thermal conductivity of pore fluid, the exact mathematical function between these two parameters is not self-evident due to variations in pore structure, microfracturing, and degree of saturation.
Most of the metacarbonate rocks are monomineralic
(calcite or dolomite) but locally contain talc, muscovite, phlogopite, garnet, and minor tremolite.
The veins are surprisingly close to monomineralic
from a collector's point of view, especially in the sandstones.
2005) suggested that the quartz-rich nature of the sandstone is the result of a monomineralic
source area rather than a unique environment of deposition.
The nearly monomineralic
ore zone at Xikuangshan is about 2 kilometers wide and 9 kilometers long.
Calcite occurs as monomineralic
clusters and crusts, and also in association with fine crystals of realgar and orpiment (though generally not with the two simultaneously).