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Diorite was also used for stone vases by Bronze Age craftspeople, who developed considerable skill at polishing diorite and other stones. [38] The Egyptians had become skilled at shaping diorite and other hard stones by 4000 BCE. [39] A large diorite stela in the Louvre Museum dating to 1700 BCE is inscribed with the Code of Hammurabi. [40]
Quartz diorite is an igneous, plutonic rock, of felsic composition, with phaneritic texture. Feldspar is present as plagioclase (typically oligoclase or andesine ) with 10% or less potassium feldspar.
For example, Coastal Batholith of Peru consists of 7–16% gabbro and diorite, 48–60% tonalite (including trondhjemite), and 20–30% granodiorite, with 1–4% granite. [22] These TTG rocks in continental arc batholiths may partially originate from the magma differentiation (i.e. fractional crystallisation ) of the subduction induced mantle ...
Nepheline-bearing diorite is an intrusive rock with a composition intermediate between diorite and nepheline diorite.It is defined in the QAPF classification as coarse-grained igneous rock in which feldspathoids makes up 0% to 10% of the QAPF mineral fraction and are predominantly nepheline; plagioclase makes up 90% or more of the total feldspar content; and the plagioclase is sodium-rich (%An ...
In a few cases, such as the diorite-gabbro-anorthite field, additional mineralogical criteria must be applied to determine the final classification. [20] Where the mineralogy of an volcanic rock can be determined, it is classified using the same procedure, but with a modified QAPF diagram whose fields correspond to volcanic rock types. [20]
The Big Timber Stock, a large igneous intrusion, forms the bedrock in the Crazy Mountains. [1] The stock is of Tertiary age, and consists of diorite and gabbro with zones of Quartz Monzodiorite, which has been intruded by many dikes and sills.
The various rock types that were produced here shows evidence of shallow level degassing, fractional crystallization, and magma mixing. [9] The main crystals present consist of olivine and latite . Geochemical data suggests fractional crystallization of olivine and micas that were accompanied by large-scale mixing of magmas.
The Y level or wye level is the oldest and bulkiest of the older style optical instruments. A low-powered telescope is placed in a pair of clamp mounts, and the instrument then leveled using a spirit level, which is mounted parallel to the main telescope. The term dumpy level (also builder's level) endures despite the evolution in design. They ...