Quartz monzonite is an intrusive,

felsic In geology, felsic is a modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz.Marshak, Stephen, 2009, ''Essentials of Geology,'' W. W. Norton & Company, 3rd ed. It is contrasted with mafic rocks, whi ...

igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock ...

that has an approximately equal proportion of

orthoclase Orthoclase, or orthoclase feldspar (endmember formula K Al Si3 O8), is an important tectosilicate mineral which forms igneous rock. The name is from the Ancient Greek for "straight fracture," because its two cleavage planes are at right angles t ...

and

plagioclase Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more prope ...

feldspar Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feldsp ...

s. It is typically a light colored

phaneritic A phanerite is an igneous rock whose microstructure is made up of crystals large enough to be distinguished with the unaided human eye. In contrast, the crystals in an aphanitic rock are too fine-grained to be identifiable. Phaneritic texture fo ...

(coarse-grained) to

porphyritic Porphyritic is an adjective used in geology to describe igneous rocks with a distinct difference in the size of mineral crystals, with the larger crystals known as phenocrysts. Both extrusive and intrusive rocks can be porphyritic, meaning all ...

granitic rock. The plagioclase is typically intermediate to sodic in composition, andesine to oligoclase.

Quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...

is present in significant amounts.

Biotite Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula . It is primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more alumino ...

and/or

hornblende Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole. Hornblende minerals are common in igneous and metamorphic rocks ...

constitute the dark minerals. Because of its coloring, it is often confused with

granite Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...

, but whereas granite contains more than 20% quartz, quartz monzonite is only 5–20% quartz. Rock with less than five percent quartz is classified as

monzonite Monzonite is an igneous intrusive rock, formed by slow cooling of underground magma that has a moderate silica content and is enriched in alkali metal oxides. Monzonite is composed mostly of plagioclase and alkali feldspar. Syenodiorite is an o ...

. A rock with more alkali feldspar is a

syenite Syenite is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at all, occurs in relatively small concentrations (< 5%). Some syenites contain larger proport ...

whereas one with more plagioclase is a

quartz diorite Quartz diorite is an igneous, plutonic ( intrusive) rock, of felsic composition, with phaneritic texture. Feldspar is present as plagioclase (typically oligoclase or andesine) with 10% or less potassium feldspar. Quartz Quartz is a hard, ...

.Classification of Igneous Rocks
The fine grained

volcanic rock Volcanic rock (often shortened to volcanics in scientific contexts) is a rock formed from lava erupted from a volcano. In other words, it differs from other igneous rock by being of volcanic origin. Like all rock types, the concept of volcanic r ...

equivalent of quartz monzonite is

quartz latite A quartz latite is a volcanic rock or fine grained extrusive rock composed mostly of alkali feldspar and plagioclase with some quartz. It forms from the rapid cooling of magma of intermediate composition but moderately enriched in alkali metal ...

. The term adamellite was originally applied by A. Cathrein in 1890 to

-bearing tonalite (likely a

granodiorite Granodiorite () is a coarse-grained (phaneritic) intrusive igneous rock similar to granite, but containing more plagioclase feldspar than orthoclase feldspar. The term banatite is sometimes used informally for various rocks ranging from gra ...

) at Monte Adamello, Italy, in 1890, but later came to refer to quartz monzonite. The term is now deprecated. Quartz monzonite porphyry is often associated with

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

mineralization in the

porphyry copper Porphyry copper deposits are copper ore bodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Predating or associated with those fluids are vertical dikes of ...

ore Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 Apr ...

deposits.

Geographic distribution

United States

In the White Mountains and western highlands of

New Hampshire New Hampshire is a U.S. state, state in the New England region of the northeastern United States. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Gulf of Maine to the east, and the Canadian province of Quebec t ...

, the Kinsman Quartz Monzonite is an extensive formation that underlies

Kinsman Mountain Kinsman Mountain is a mountain located in Grafton County, New Hampshire. It is named after Nathan Kinsman, an early resident of Easton, New Hampshire, and is part of the Kinsman Range of the White Mountains. To the northeast, Kinsman is connec ...

, parts of

Franconia Notch Franconia Notch (elev. ) is a major mountain pass through the White Mountains of New Hampshire. Dominated by Cannon Mountain to the west and Mount Lafayette to the east, it lies principally within Franconia Notch State Park and is traversed by ...

Mount Cardigan Mount Cardigan is a prominent bare-rock summit in the towns of Orange and Alexandria in western New Hampshire, USA. While its peak is only above sea level, it has extensive areas of bare granite ledges and alpine scrub, giving it the feel to hik ...

, and

Mount Sunapee Mount Sunapee (or Sunapee Mountain on federal maps) is a mountain ridge in the towns of Newbury and Goshen in western New Hampshire, United States. Its highest peak, at the north end of the mountain, is above sea level. The mountain has three ...

Stone Mountain Stone Mountain is a quartz monzonite dome Inselberg, monadnock and the site of Stone Mountain Park, east of Atlanta, Georgia. Outside the park is the small city of Stone Mountain, Georgia. The park is the most visited tourist site in the state o ...

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

is a large quartz monzonite

monadnock An inselberg or monadnock () is an isolated rock hill, knob, ridge, or small mountain that rises abruptly from a gently sloping or virtually level surrounding plain. In Southern Africa a similar formation of granite is known as a koppie, a ...

. Quartz monzonite extracted from a quarry in

Little Cottonwood Canyon Little Cottonwood Canyon lies within the Wasatch-Cache National Forest along the eastern side of the Salt Lake Valley, roughly 15 miles from Salt Lake City, Utah. The canyon is part of Granite, a CDP and "Community Council" designated by Salt ...

was used to build several buildings in

Salt Lake City Salt Lake City (often shortened to Salt Lake and abbreviated as SLC) is the Capital (political), capital and List of cities and towns in Utah, most populous city of Utah, United States. It is the county seat, seat of Salt Lake County, Utah, Sal ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

, including

the Church of Jesus Christ of Latter-day Saints The Church of Jesus Christ of Latter-day Saints, informally known as the LDS Church or Mormon Church, is a Nontrinitarianism, nontrinitarian Christianity, Christian church that considers itself to be the Restorationism, restoration of the ...

Salt Lake Temple The Salt Lake Temple is a temple of the Church of Jesus Christ of Latter-day Saints on Temple Square in Salt Lake City, Utah, United States. At , it is the largest Latter-day Saint temple by floor area. Dedicated in 1893, it is the sixth temple ...

Church Administration Building The Church Administration Building (CAB) is an administrative office building in Salt Lake City, Utah, United States serving as the headquarters of the Church of Jesus Christ of Latter-day Saints (LDS Church), the fourth-largest Christian denomin ...

, and

Conference Center A convention center (American English; or conference centre in British English) is a large building that is designed to hold a convention, where individuals and groups gather to promote and share common interests. Convention centers typica ...

, as well as the

Utah State Capitol The Utah State Capitol is the house of government for the U.S. state of Utah. The building houses the chambers and offices of the Utah State Legislature, the offices of the Governor, Lieutenant Governor, Attorney General, the State Auditor and ...

. The large boulders of

Joshua Tree National Park Joshua Tree National Park is an American national park in southeastern California, east of San Bernardino and Los Angeles and north of Palm Springs, California, Palm Springs. It is named after the Joshua trees (''Yucca brevifolia'') native to t ...

in southern California are quartz monzonite. A large pluton in the Atlanta lobe of the

Idaho Batholith The Idaho Batholith is a granitic and granodioritic batholith of Cretaceous- Paleogene age that covers approximately of central Idaho and adjacent Montana. The batholith has two lobes that are separate from each other geographically and geo ...

, near McCall,

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

, is made of quartz monzonite.Idaho Batholith
/ref> The

Guilford Quartz Monzonite The Guilford Quartz Monzonite is a Silurian or Ordovician quartz monzonite pluton in Howard County, Maryland. It is described as a biotite-muscovite-quartz monzonite which occurs as discontinuous lenticular bodies which intrude mainly throug ...

and

Woodstock Quartz Monzonite The Woodstock Quartz Monzonite is a Silurian or Ordovician quartz monzonite pluton in Baltimore County, Maryland. It is described as a massive biotite-quartz monzonite which intrudes through the Baltimore Gneiss at a single locality surrounding ...

, probably comagmatic, are located in central

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

Australia

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

, Castle Hill, Mount Stuart and Mount Louisa around

Townsville Townsville is a city on the north-eastern coast of Queensland, Australia. With a population of 180,820 as of June 2018, it is the largest settlement in North Queensland; it is unofficially considered its capital. Estimated resident population, 3 ...

represent a large quartz monzonite province.

References

External links

* {{commonscat-inline Igneous petrology Granitic rocks