Norite is a gabbro with predominantly orthorhombic pyroxene (enstatite or hypersthene) rather than clinopyroxenes. IUGS classification is opx/(opx + cpx) > 95, 0-5% Q, P/(A + P) > 90, and pl/(pl + px + ol) is 10 - 90. The opx may sometimes be identified in hand specimen by the presence of Schiller luster.

2012年11月1日 · Pairs of coexisting Opx-Cpx yielded average igneous crystallization temperatures of 908 °C for the norite and 958 °C for the charnockites. Confirmation for these values has been additionally obtained from calculations based on the geothermometer proposed by Andersen et al. (1993) .

To investigate the potential antiquity and deep crustal origin of the Civet Cat norite, we have undertaken high resolution microstructural analyses of the major, minor, and accessory minerals to characterize the primary igneous textures and secondary overprinting by …

2017年8月4日 · We show that a norite at the contact between a mafic diorite intrusion and a pelitic granulite gneiss formed via a reaction similar to that first postulated by N.L. Bowen in 1928, i.e., clinopyroxene (Cpx) + sillimanite = anorthite (An) + orthopyroxene (Opx).

2020年9月21日 · Phase equilibria modelling and pyroxene thermobarometry constraints on metamorphic conditions of the norite belt. Opx = orthopyroxene, cpx = clinopyroxene, ol = olivine, pl = plagioclase, hb = hornblende, bi = biotite, q = quartz, ru = rutile, sph = sphene, liq = liquid.

To investigate the potential antiquity and deep crustal origin of the Civet Cat norite, we have undertaken high resolution microstructural analyses of the major, minor, and accessory minerals to characterize the primary igneous textures and secondary overprinting by …

The principal difference between norite and gabbro, however, is the type of pyroxene of which it is composed; norite is predominately composed of orthopyroxenes, largely high magnesian enstatite or an iron bearing intermediate hypersthene, whereas the principal pyroxenes in gabbro are clinopyroxenes, generally medially iron-rich augites.

orthopyroxene (opx), and clinopyroxene (cpx). They are common constituents of plutonic, volcanic, and metamorphic rocks, and may show extreme compositional variation. Rocks that are composed only of olivine and/or pyroxenes are known as ultramafics. Plutonic rocks composed of plagioclase and clinopyroxene are gabbros,

2020年9月22日 · (A) Typical norite with granulite-facies assemblage of orthopyroxene (opx), clinopyroxene (cpx), plagioclase (pl), and hornblende (hb). (B) Cross-polarised light photomicrograph of...

Gabbro and norite are basic intrusive rocks composed principally of calcic plagioclase and pyroxene, with or without olivine. In gabbro the dominant ferromagnesian mineral is clinopyroxene, whereas it is orthopyroxene in norite. The expression “gabbroic rocks” includes both gabbro and norite.