How is granodiorite formed?
Granodiorite is a plutonic igneous rock, formed by intrusion of silica-rich magma, which cools in batholiths or stocks below the Earth’s surface. It is usually only exposed at the surface after uplift and erosion have occurred.
Is feldspar a granite?
The principal constituent of granite is feldspar. Both plagioclase feldspar and alkali feldspar are usually abundant in it, and their relative abundance has provided the basis for granite classifications.
Is monzonite a rock?
Monzonite is an intermediate igneous intrusive rock composed of approximately equal amounts of K–feldspars and Na–plagioclase with minor amount of quartz (<5%) and ferromagnesian minerals (hornblende, biotite and pyroxene).
Where can granodiorite be found?
An intrusive igneous rock, granodiorite often forms large masses in the roots of mountain ranges, such as the Andes. It also often occurs in association with granitic batholiths. Indeed, granodiorite is often confused with granite, a rock with which it shares a similar appearance, texture, and composition.
Does granodiorite contain gold?
In Federal open pit, the granodiorite is coarse-grained in the northern half, and a fine-grained granodiorite in the south, with both hosting gold. These two types of granodiorite are rather similar in both mineralogy and geochemistry. There is also a subordinate fine- grained monzodiorite.
What makes feldspar red?
The color is from the presence of lead. The high potassium content and high strength of K-feldspar make it the best mineral for potassium-argon dating. Alkali feldspar is a crucial ingredient in glass and pottery glazes. Microcline has a minor use as an abrasive mineral.
Where can I find monzonite?
monzonite is not a common rock, but is typically found around the edges of other felsic plutons, such as plagiogranites or granodiorites. That is, it is typical of continents. In this detail we see the white translucent plagioclase, and some hints of faint pink orthoclase.
Is quartz a Phaneritic?
It is typically a light colored phaneritic (coarse-grained) to porphyritic granitic rock. The plagioclase is typically intermediate to sodic in composition, andesine to oligoclase. Quartz is present in significant amounts.
What is granodiorite rock?
Granodiorite, medium- to coarse-grained rock that is among the most abundant intrusive igneous rocks. It contains quartz and is distinguished from granite by its having more plagioclase feldspar than orthoclase feldspar; its other mineral constituents include hornblende, biotite, and augite.
Is gold found in basalt rock?
Mid ocean ridge basalt has lower gold concentration than ocean-island and volcanic-arc basalt, due mainly to lower oxygen fugacity at MOR settings that causes sulphur saturation. Gold concentrations in sedimentary rocks increase with increasing abundance of diagenetic sulphide minerals and organic matter.
Where is basalt found?
It is found all over Earth, but especially under the oceans and in other areas where Earth’s crust is thin. It formed in the Isle Royale-Keweenaw region because of the Midcontinent Rift. Most of Earth’s surface is basalt lava, but basalt makes up only a small fraction of continents.
Where are the monzogranites found in the world?
In Northern Portugal, along the Vigo-Régua Shear Zone, the monzogranites belong to the syn-F3 biotite granitoid group. They present a porphyritic texture (potassium feldspar megacrysts) and mafic microgranular enclaves that decrease in frequency from South to North.
What are the granodiorites of the monzogranite granite?
The granites are composed of quartz + potassium feldspar + plagioclase (andesine/oligoclase) + biotite + zircon + monazite + apatite + ilmenite ± muscovite. The studied granodiorites-monzogranites are moderately peraluminous, [ (A/KNC)m:1.19–1.39], with SiO 2 contents between 62 and 70%. (Simoes, 2000).
What kind of igneous rock is monzoite?
Monzonitic magma most likely forms only a part of a generally more acidic (granitic) intrusions. Although monzonite itself is not a particularly well-known or widespread rock type, but it has given part of its name (monzo-) as a prefix to several other varieties of plutonic rocks (monzogranite, monzogabbro, foid monzosyenite, etc.).
Where was the monzogranite pluton found in Egypt?
Granitoids in the Gabal El-Urf area in eastern Egypt consist of a monzogranite pluton, belonging to the Younger Granite province, emplaced in granodioritic rocks.
