Accessory luminescent minerals like diamond, apatite, bearthite are easy to identify in thin section even if they occur in very small abundance within the matrix or as inclusions.The CL method presented here for UHP-metamorphic rocks is recommended as a pathfinder for the discovery of internal ...
This transformation of minerals marks the point in the rock’s history when it is no longer sedimentary but becomes the low-grade metamorphic rock known as "slate." Slate is has a dull luster, it can be split into thin sheets along the parallel mineral alignments, and the thin sheets will...
important new data became available for green and other clay minerals. It might be remarked that one advantage of green clays is that they can be easily recognized both in thin section and hand specimen. Thus, green clays became the subject of investigation as soon as XRD was coupled with mi...
The high-grade portion of the Sanbagawa “proper” rocks has long been regarded to consist of non-eclogite facies rocks, because petrological studies that used the present minerals in these rocks showed that the peak metamorphic condition in the highest-grade part of the Sanbagawa “proper” ...
The leucosome is surrounded by a thin (ca. 1–2 mm) layer of bio- tite selvages, which represent the melanosome (Figs. 2b–c). The leucosome layers often show ptygmatic folding. Petrography and microstructural relations Migmatites from all three localities contain the minerals plagio- ...
Table 1 Description of cross section colors, micropore morphology, XRD peaks of pyrometamorphic minerals and main and sub bands of FT-IR (transmittance) vibrations for the representative samples (clc: calcite, geh: gehlenite, hem: hematite, ill: illite). Full size table Figure 9 shows the ref...
Unlike feldspars which break down to form clay minerals, the weathering debris of quartzite is quartz. It is therefore not a rock type that contributes well to soil formation. For that reason it is often found as exposed bedrock with little or no soil cover....
and other flat or elongated minerals into thin layers, or foliation. At least 50 percent of the mineral grains in schist are aligned this way (less than 50 percent makes it gneiss). The rock may or may not be actually deformed in the direction of the foliation, although a strong foliation...
are often in direct contact with fine- to coarse-grained, massive to slightly foliated leu- cogranites (Figs. 2, 3) composed of quartz, plagioclase, alkali feldspar, biotite, muscovite ± garnet ± sillimanite; apatite, chlorite, sphene, rutile, ilmenite and zircon are accessory minerals. Roun...
The samples collected in the field were used to prepare the thin sections and to separate the accessory minerals. Rutile and monazite grains were separated from the crushed rock by using heavy liquid and magnetic techniques, handpicked under a binocular microscope and then mounted to disks. Thin ...