from The American Heritage® Dictionary of the English Language, 4th Edition
- n. See gabbro.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A granular crystalline rock consisting essentially of a triclinic feldspar (such as labradorite) and hypersthene.
from the GNU version of the Collaborative International Dictionary of English
- n. A granular crystalline rock consisting essentially of a triclinic feldspar (as labradorite) and hypersthene.
from The Century Dictionary and Cyclopedia
- n. A rock which consists essentially of a mixture of a plagioclase feldspar with a rhombic pyroxene (enstatite, bronzite, hypersthene). See gabbro.
Masses sufficiently large for cutting are found in the norite of the Kupferberg in the Fichtelgebirge, and in the serpentine of Kraubat near Leoben in Styria.
The granitic rocks included granite, gneisses, syenites and norite.
However, the intimate association of the ores with the primary minerals in the magma, together with their absence from higher parts of the norite and from the extraneous rocks far from the contact, indicate to other investigators that they were not brought in from outside in vagrant solutions which followed the intrusion of the main magma, but that they were segregated within the magma essentially in place.
Their textures and their intercrystallization with the primary minerals of the igneous rock have suggested that they are essentially a part of the norite mass, and that they crystallized during some segregative processes which were effective before the magma had solidified.
The occurrence of these heavy ores near the base of the norite naturally suggests that they were segregated by sinking to the bottom of the molten magma, but this conclusion implies certain physical conditions of the magma which have not yet been proved.
York the emery deposits are segregations of aluminum and iron oxides in norite (a basic igneous rock).
The few ore bodies known have been formed as the result of unusual segregation of the nickel in highly magnesian igneous rock of the norite or gabbro type, at the time of its solidification or soon after; and in some cases, in order to produce the nickel ore, still further concentration by the agency of weathering has been necessary.
Near the ores there are likely to be granitic rocks, which, like the ores, seem to be segregations from the norite magma.
These are situated in the basal portions of a great norite intrusive, and are ascribed to segregation of the sulphides as the rock solidified.
Locally both the ores and the associated granitic rocks replace the main norite body in such a fashion as to indicate their slightly later crystallization.