StudentShare
Contact Us
Sign In / Sign Up for FREE
Search
Go to advanced search...

Origin and evolution of peralkaline rhyolite - Research Paper Example

Cite this document
Summary
All around the world alkaline rocks normally occur in several diverse petrological associations, tectonic settings, and have such varied chemical compositions. Therefore, all alkaline rocks cannot be produced by single parental magma. In addition, alkaline rocks occur in…
Download full paper File format: .doc, available for editing
GRAB THE BEST PAPER92.4% of users find it useful
Origin and evolution of peralkaline rhyolite
Read Text Preview

Extract of sample "Origin and evolution of peralkaline rhyolite"

Download file to see previous pages

Rhyolites in most cases are porphyritic, glassy groundmass or fine-grained. Often, it is not easy to recognize rhyolites without doing a chemical analysis because they have a glassy groundmass nature. Most rhyolites principally consist of glass, and are referred to as obsidian or are partly devitrified and are called pitchstones. In addition, most are lined because of the small disparities in composition of the glass, thereby resulting to differences in crystallites content. Alkali rhyolites are considered alkali feldspars if their content is >90% feldspars.

They are peralkaline and in most instances contain alkali pyroxenes and/or amphiboles. The alkali rhyolites can either be pantellerite or commendite, and peralkaline rhyolites are grouped under pantellerite. Peralkaline rhyolites are mostly widespread in continental rift settings. They contain alkali quartz and feldspar as their key phenocryst phase. Peralkaline rhyolites are distinguished from metaluminous rhyolites because of the presence of amphiboles and sodic pyroxenes in them. They may at times be found in oceanic island settings.

In addition, they are commonly associated with, trachytes, hawaiites, mugearites, and basalts that are slightly alkaline and silica-saturated. Additionally, peralkaline rhyolites have high iron levels and low aluminum levels compared to comendite like the peralkaline igneous rock. An example of peralkaline rhyolite is the Pantelleria, which is usually found occurring as a vitrophyre that comprises phenocrysts of sanidine or anorthoclase. Furthermore, quartz occurs in peralkaline rocks that are strong.

Mafic minerals can include aenigmatite, aegirine, ilmenite, fayalite, and sodic amphibole (normally ferrorichterite or arfvedsonite) (Ray, Gautam, and Biswajit, p.47). White et al. (p.133) asserts that often, the formation of peralkaline magmas comes as a result of the sodium-rich clinopyroxene (i.e., aegirine and

...Download file to see next pages Read More
Cite this document
  • APA
  • MLA
  • CHICAGO
(“Origin and evolution of peralkaline rhyolite Research Paper”, n.d.)
Origin and evolution of peralkaline rhyolite Research Paper. Retrieved from https://studentshare.org/physics/1690483-origin-and-evolution-of-peralkaline-rhyolite
(Origin and Evolution of Peralkaline Rhyolite Research Paper)
Origin and Evolution of Peralkaline Rhyolite Research Paper. https://studentshare.org/physics/1690483-origin-and-evolution-of-peralkaline-rhyolite.
“Origin and Evolution of Peralkaline Rhyolite Research Paper”, n.d. https://studentshare.org/physics/1690483-origin-and-evolution-of-peralkaline-rhyolite.
  • Cited: 0 times

CHECK THESE SAMPLES OF Origin and evolution of peralkaline rhyolite

Origin of Agriculture: Middle East and Mesoamerica

This paper origin of Agriculture: Middle East and Mesoamerica will compare and contrast the origin of agriculture.... Even though localized climate change seem to be the most favored justification for the agricultural origin, the case that domesticated agriculture was 'invented, proposes that social reasons could have been much instrumental.... However as of to date, identifying the precise agricultural origin in the region remains problematic for the reason that the change from...
4 Pages (1000 words) Essay

Evolution and Origin of Diseases: Darwinian Medicine

The study on diseases evolution is a continuation of the Darwin evolution of adaptation in which organisms had to adapt to the environment to ensure their survival.... Likewise, an understanding of evolution of causes of diseases ensures effective understanding of the necessary treatment.... The evolution of these pathogens makes there antibiotics ineffective and cannot be use as a cure (Nesse & George 39).... … evolution and Origin of Diseases: Darwinian Medicine Darwin medicine plays a critical role in the understanding of diseases and their subsequent treatment....
6 Pages (1500 words) Essay

Origin and Evolution of Tetrapods and Fossils

The paper "origin and evolution of Tetrapods and Fossils" explain that fossils are creations transformed from other creatures.... The recently found fossil fish shows similarities with the species famous as Eusthenopteron.... Its large proportions seem to be alike tetrapod than just of any other fish....
4 Pages (1000 words) Term Paper

Origins of hominid bipedalism

This hypothesis is widely accepted as it explains the evolution of human characteristics such as walking on two limbs.... There are numerous hypothesis developed by anthropologists trying to reconnect this… Therefore, bipedalism evolution in human beings cannot be pointed to energy saving purposes during locomotion but bipedalism in humans is as efficient as quadrapedalism in land 5 April Origins of hominid bipedalism Most terrestrial mammals use four limbs for locomotive a purpose that is they are quadrepedal humans and other great apes (though circumstantially) use their limbs to locomotive purposes....
2 Pages (500 words) Essay

JavaScript-Same Origin Policy

This essay talks about a security concept, the same origin policy, a concept used when there is a need to isolate documents retrieved from distinct origins.... hellip; This origin policy always starts with trust; a web page owns its data and is free to submit that data to the original website.... JavaScript-Same origin Policy Introduction As a security concept, the same origin policy is a concept used when there is a need to isolate documents retrieved from distinct origins....
1 Pages (250 words) Essay

The origin of humans

The evolution of man contrasts the biological definition of species in the aspect of appearance.... They concur in appearance but form different species hence more confusion when dating the human evolution.... The challenge is that, most living species interbreeding documentation is imperative since past fossils can no longer mate although the need for dating human evolution and origin is still crucial.... Human evolution (1st ed....
1 Pages (250 words) Coursework

Definition of Igneous Rocks

 This paper aims to expand on the igneous rock phenomenon by focusing on the descriptions and explanations of the petrography and petrochemistry of the rock types in reference to maps and diagrams of the locations where these rocks are found.... hellip;  Rocks are divided into three categories namely sedimentary, metamorphic, and igneous rocks....
4 Pages (1000 words) Term Paper

Tectonic Setting of the Devils Waterhole

This paper ''Inks Lake Field '' tells that Devil's Waterhole is situated within the eastern edge of the Mesoproterozoic acquaintance in the Llano Uplift.... The Devil's Waterhole rocks regarding the Inks Lake Gneiss and granitic gneiss are 1231 million years old.... hellip; Valley Spring gneiss was formed initially from the corresponding remelted rhyolitic volcanic rocks, tuffaceous and corresponding cash-flow tuffs sediments, which intensely bury them....
6 Pages (1500 words) Essay
sponsored ads
We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.
Contact Us