Search results
Results from the WOW.Com Content Network
Andesite (/ ˈ æ n d ə z aɪ t /) [1] is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica -poor basalt and silica-rich rhyolite . It is fine-grained ( aphanitic ) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende .
Volcanic rocks are classified based on their formation environment and particle size. They can originate from lava flows or be ejected explosively as fragmented material known as tephra. Lava – When molten rock erupts and solidifies on the Earth's surface, it forms coherent volcanic rocks such as basalt, andesite, and rhyolite. The size and ...
An igneous, volcanic rock with a high iron content. It is an extrusive rock of the same general composition as andesite, but a less calcic feldspar. Synonymous with quartz andesite. daughter product Any distinct isotope produced by the radioactive decay of an atomic nucleus. delta
The individual crystals in an aphanitic igneous rock are not distinguishable to the naked eye. Examples of aphanitic igneous rock include basalt, andesite, and rhyolite. Glassy or vitreous textures occur during some volcanic eruptions when the lava is quenched so rapidly that crystallization cannot occur. The result is a natural amorphous glass ...
Plutonism is the geologic theory that the igneous rocks forming the Earth originated from intrusive magmatic activity, with a continuing gradual process of weathering and erosion wearing away rocks, which were then deposited on the sea bed, re-formed into layers of sedimentary rock by heat and pressure, and raised again.
Arguably their best team — in 2007 — was the first to go 18-0 … only to lose at the end. It’s not a shock that some team would come along to challenge that run of greatness.
This article related to petrology is a stub. You can help Wikipedia by expanding it.
Editor’s Note: In Snap, we look at the power of a single photograph, chronicling stories about how both modern and historical images have been made.. By his own admission, James Crombie knew ...