Orthogneiss

orthogneiss

[′ōr·thə‚nīs]
(geology)
Gneiss originating from igneous rock.

Orthogneiss

 

rock formed as the result of change, or metamorphosis, of such igneous rocks as granites and quartz diorites. Orthogneiss is distinguished from paragneiss, which derives from sedimentary rock.

References in periodicals archive ?
2005, Exotic orthogneiss pebbles from Paleocene flysch of the Dukla Nappe (Outer Eastern Carpathians, Poland).
2008): (1) the deformed and metamorphosed rocks of the Precambrian Bucaramanga Gneiss Complex, the Lower Paleozoic Silgara Formation and the Ordovician Orthogneiss and (2) a Triassic-Jurassic post-orogenic magmatism with calc-alkaline affinity which developed after the Paleozoic syn-orogenic magmatism with alkaline affinity (e.
In contrast, the Melford Formation has somewhat different rock types, including biotite, biotite-cordierite, sillimanite, and garnet-bearing schist, marble, quartzite, and granitic orthogneiss (White and Boehner 2008).
In the study area lithological units is outcrops the second to fourth periods, which from old to new are as follows: phyllite, ouartzite, paragneiss, marble, shell, sandstone with tufa, volcanic rocks, crystalline limestone locally with fosolina, metamorphic volcanic and tufa, cherty limestone, phyllite, metamorphic quartzarenite, micaschist, metadolomite, amphibolite, limestone, shale and sandstone, schist hornfels, orthogneiss, granodiorite, oput rock, shale and phyllite sandstone, granite, granodiorite, diorite, dolomitic lime, radiolarit breccia, rodist lime, orbitoline, radiolarat, black and blue marl with limestone, alluvium.
The Early Proterozoic Beesham Complex which comprises of hornblende-biotite granodiorite gneiss leucogranite pegmatites biotite orthogneiss and mafic intrusion is overlain by the Early to Late Proterozoic rocks collectively termed as Karora group (Treloar et al.
In the mid-1960s, clefts in orthogneiss around the Ritter Pass and on the Gischihorn (horn = "peak") and Helsenhorn, about 10 km south of the Binntal, yielded slightly corroded but still sharp, deep rose-pink octahedral fluorite crystals to a remarkable 8 cm on edge (Graeser, 1995).
Western gradient (G2) is located at the boundary between orthogneiss of the Orlice-Snieznik Complex (G3) and rocks of the Stronie Group and the Stare Mesto Belt (G4 + G5), which continues to north as the Hranicna Belt.
The Trousers Lake suite also includes minor amphibolite (metabasalt and metagabbro) and felsic orthogneiss that have been correlated with volcanic rocks of the Bathurst Supergroup (Fyffe et al.
The Northern Karakoram Terrane comprises sedimentary units such as Pasu limestones, Pasu slates, chiastolite slates and precollision K2 orthogneiss and granites.
A pre-tectonic granodioritic orthogneiss of this belt has been dated by U-Pb SHRIMP in zircons at ca.