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 ...
scale of individual grains, mass transport takes place during all phase transformations; on the scale of a thin section, it is probably the rule for regional metamorphism; on the scale of a hand (-sized) specimen, it can be observed frequently; and on a larger scale, it is the exception...
Cataclasite (kat-a-CLAY-site) is a fine-grained breccia produced by grinding rocks into fine particles, or cataclasis. This is a microscopic thin section. 05 of 18 Eclogite Andrew Alden Eclogite ("ECK-lo-jite") is an extreme metamorphic rock formed by regional metamorphism of basalt under ...
Garnet mica schist in thin section: This is a microscopic view of a garnet grain that has grown in schist. The large black grain is the garnet, the red elongate grains are mica flakes. The black, gray, and white grains are mostly silt or smaller size grains of quartz and feldspar. The...
Quartzite Under a Microscope: A specimen of the Bo Quartzite collected near South Troms, Norway, observed through a microscope in thin-section under cross-polarized light. The quartz grains in this view range in color from white to gray to black depending upon their optical orientation. The ...
Section snippets Geological outline The Sanbagawa HP metamorphic belt extends roughly in an E–W direction from the Kanto Mountains to Kyushu Island for over 800 km in central to SW Japan (Fig. 1). It occurs as a subhorizontal thin tectonic slice bounded by a normal fault on the top and...
Off the southern margin of Tasmania is a large area of thin continental crust (South Tasman Rise and East Tasman Plateau) derived from Mesozoic Gondwana. Dredging during two scientific cruises in this area recovered metamorphic rocks at 28 localities. Upper amphibolite facies paragneiss, from the ...
In sample 91CH08b, theSr/Ca value of the epidote varies from grain to grain evenwithin a single thin section, and some epidote grains have 244NAGASAKI AND ENAMI: Sr-BEARING ZOISITE AND EPIDOTE IN UHP ROCKSFIGURE3.Histograms of SrO concentrations (wt%) in zoisite and epidote from eclogite ...
Our observations during mineral exploration east of Yamethin and elsewhere in the belt between Tatkon and north of Mandalay (Fig. 3) now allow correlation of rock-types among the individual quarries, providing a sequence of geological events for this part of the MMB. This sequence is of ...
The observation of microdiamonds below the polished surface of the thin section, their octahedral crystal shape, the existence of aggregated crystals, dissolution pits on diamond surfaces, variation of their grain size, and occurrence of coesite, all confirm their in-situ origin, as opposed to any...