Basaltic andesite
Encyclopedia
Basaltic andesite is a black volcanic rock
containing about 55% silica. Minerals in basaltic andesite include olivine
, augite
and plagioclase
. Basaltic andesite can be found in volcanoes around the world, including in Central America
and the Andes
of South America
. Basaltic andesite is common in the volcanoes near McKenzie Pass
in Oregon
, United States
.
Volcanic rock
Volcanic rock is a rock formed from magma erupted from a volcano. In other words, it is an igneous rock of volcanic origin...
containing about 55% silica. Minerals in basaltic andesite include olivine
Olivine
The mineral olivine is a magnesium iron silicate with the formula 2SiO4. It is a common mineral in the Earth's subsurface but weathers quickly on the surface....
, augite
Augite
Augite is a single chain inosilicate mineral, 2O6. The crystals are monoclinic and prismatic. Augite has two prominent cleavages, meeting at angles near 90 degrees.-Characteristics:Augite is a solid solution in the pyroxene group...
and plagioclase
Plagioclase
Plagioclase is an important series of tectosilicate minerals within the feldspar family. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a solid solution series, more properly known as the plagioclase feldspar series...
. Basaltic andesite can be found in volcanoes around the world, including in Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and the Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
of South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. Basaltic andesite is common in the volcanoes near McKenzie Pass
McKenzie Pass
McKenzie Pass is a mountain pass in the Cascade Range in central Oregon, United States.It is located at the border of Linn and Deschutes counties, approximately 20 mi northwest of Bend, between the Three Sisters to the south and Mt. Washington to the north...
in Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.