Some of the rocks related to norite are: 1. Gabbronorite. Gabbronorite is a mafic plutonic rock with mainly calcic plagioclase and roughly equal amounts of orthopyroxene and clinopyroxene. This …

Plutonic Rocks. When magma cools slowly underground and solidifies there, it usually grows crystals big enough to be seen easily with the naked eye. These visible crystals comprise the whole rock, not just part of it as in a porphyritic, fine-grained igneous rock. The texture of an igneous rock made up entirely of crystals big enough to be ...

The formation of ore deposits of the platinum-group elements (PGE) requires that their concentrations be raised about four orders of magnitude above typical …

Plutonic and Volcanic rocks. Answer. Plutonic rock Volcanic rock; They are also called intrusive rocks. ... Rocks are a source of precious metals like gold, silver, platinum etc. Apart from minerals and fossil fuels, even rock wastes have now been used in manufacturing various articles. Question 3(c)

Platinum (Pt) is a rare and valuable metal that is widely used in various industrial applications due to its unique properties. Platinum ore refers to the naturally occurring rocks or minerals that contain significant concentrations of platinum, usually in the form of platinum group minerals (PGMs) and associated minerals. Platinum ore is …

Plutonic rocks differ fundamentally from volcanic rocks in several ways. The most prominent distinction lies in their cooling rate. Plutonic rocks cool slowly beneath the Earth's surface, fostering the growth of large crystals. Volcanic rocks, on the other hand, cool rapidly at the surface, resulting in smaller grains or even glassy textures.

Syenite is a coarse-grained, plutonic (intrusive) igneous rock that primarily consists of the minerals feldspar, typically orthoclase feldspar, and often includes smaller amounts of other minerals such as hornblende, mica, or amphibole.Unlike granite, which is another common intrusive igneous rock, syenite contains minimal to no quartz.The …

Media in category "Plutonic rocks" The following 13 files are in this category, out of 13 total.

A plutonic rock is also called an intrusive rock as it is derived from magma that intruded the rock layers but never reached the earth's surface. If magma does manage to reach the earth's surface, it is no longer insulated by the rocks around it and will, therefore, cool rapidly. Magma that reaches the earth's surface through a fissure or ...

Knowledge of the 187 Os/ 188 Os ratio as well as the inventories of rhenium and platinum group elements (PGE) in oceanic crust allows quantification of the proportion of recycled oceanic crust in oceanic basalt sources. Our knowledge is limited by the availability of well-characterized sections of oceanic crust, specifically of the plutonic, …

While whole-rock peridotite Re-Os isotopic signatures are the core of such investigations, the Re-Os dating of individual peridotite minerals—base metal sulfides (BMS) and platinum group minerals (PGM)—that are the main hosts for Re and Os in the mantle peridotites came into play two decades ago.

A recent paper by Prof. George P. Merrill, Curator of the Department of Geology of the U. S. National Museum, Washington, upon " An Occurrence of Free Gold in Granite," describes an interesting instance of the dissemination of this noble metal in the substance of granite of normal composition believed to be from Sonora, Mexico. He …

On the QAPF diagram of plutonic rocks, syenite is defined as a plutonic rock in which alkali feldspar is 65-90% of total feldspars, and quartz is no more than 5% of QAPF content by volume. This rock has no feldspathoids. As alkali feldspar reduces, it grades into monzonite, while an increase in alkali feldspar grades this rock into alkali ...

15 rowsThe platinum-group elements (PGEs), nickel, and chromite deposits coexist in nature and are primarily hosted by mafic–ultramafic plutonic–volcanic rocks. The …

Local deep-seated volatiles, perhaps associated with floor-rock upwarpings, are responsible for potholes of the Brakspruit type.Pothole and dunite platinum-group mineral characteristics are locally superimposed on the Merensky reef platinum-group minerals, which are in the first place characterized by footwall type and perhaps …

Pyroxenite is an ultramafic plutonic igneous rock. Ultramafic means that more than 90% of the rock is composed of magnesium- and iron-rich minerals like pyroxenes, amphiboles, ... Pyroxenite and peridotite may host economically important metals like chromium, nickel, platinum, iridium, osmium, ...

Here is the chemical and mineral composition of dunite rock: 1. Chemical composition. Dunite is a basic, ultramafic rock that is poor in silica (< 45 wt. %) and high in magnesium with considerable iron. This rock is low in felsic elements like sodium, potassium, and aluminum. Also, it is low in calcium.

The main difference between plutonic and volcanic rocks is that plutonic rocks form under the surface of Earth, whereas volcanic rocks form upon exposure to air.. There three major types of rocks on Earth, which are categorized depending on the source of rock formation. These are the sedimentary rocks, igneous rocks, and metamorphic …

The former group is most commonly found along the oceanic ridges and on the ocean floor; the latter group is characteristic of the volcanic regions of the continental …

Characteristics of Plutonic Rocks. Coarse-grained texture (phaneritic): Plutonic rocks have a coarse-grained texture, characterized by visible mineral crystals that are typically larger than those found in volcanic rocks.This coarse texture results from the slow cooling and solidification of magma beneath the Earth's surface, allowing ample time for mineral …

Granite, coarse- or medium-grained intrusive igneous rock that is rich in quartz and feldspar; it is the most common plutonic rock of the Earth's crust, forming by the cooling of magma (silicate melt) at depth. Learn more about the properties and uses of granite in this article.

Such rocks are called intrusive rocks or plutonic rocks (e.g. Granite). These rocks appear on the surface only after being uplifted and denuded. ... zinc, chromite, manganese, gold, diamond and platinum. Amygdales are almond-shaped bubbles formed in basalt due to escape of gases and are filled with minerals.

The rocks of the early Archean greenstone belts are also known as the Sargur Group (Swami Nath and Ramakrishnan, 1981). The Sargur Group is comprised of conformable units of volcano-sedimentary rocks and sill-like plutonic ultramafic–mafic rocks, all of which are encompassed by the tonalite–trondhjemite-granodiorite suite …

Previous isotopic, petrologic, and geologic studies suggested a close relation in time and space between the volcanic rocks and the ultramafic complexes. Interpretation of 40 …

Such slow cooling allows time for large crystals to form, therefore, intrusive or plutonic igneous rocks have relatively large mineral crystals that are easy to see. Granite is the most common intrusive igneous rock (Figure …

Like volcanic rocks, plutonic rocks can be classified on the basis of chemical and mineralogical composition. They are also alike in that they occur at geologically active zones. Volcanic rocks and plutonic rocks differ mainly in that volcanic rocks form at the surface of a planet whereas plutonic rocks form beneath the surface.

The Itchayvayamsky Ural-Alaskan-type massif is located in the northernmost part of the Koryak-Kamchatka Platinum Belt (Russia) and is surrounded by two rivers (Kamenistaya and Itchayvayam) that both contain specific PGM …

Distribution of Gold Ill • Igneous Rocks By DAVID GOTTFRIED, JACK ].ROWE, and ROBERT I. TILLING GEOLOGICAL SURVEY PROFESSIONAL PAPER 727 An investigation of the abundance and distribution of gold in plutonic and volcanic rocks of diverse magma types and tectonic settings UNITED STATES GOVERNMENT …

platinum group; platinum ores; plutonic rocks; Precambrian; South Africa; Southern Africa; structural controls; troctolite; ultramafic composition; Hout River shear zone; Waterburg Deposit; Latitude & Longitude S26°30'00" - S21°30'00", E26°00'00" - E31°00'00" View Full GeoRef Record.

Palladium, platinum, and rhodium concentrations are reported for rocks belonging to the Peridotite zone of the Ultramafic series and the Basal series of the late Archcan Stillwater Complex, a suite of Stillwater-associated sills and dikes, and the metamorphic rocks lying within the contact aureole of the complex.