Basaltic andesite
Basaltic andesite is a volcanic rock that is intermediate in composition between basalt and andesite. It is composed predominantly of augite and plagioclase. Basaltic andesite can be found in volcanoes around the world, including in Central America[1] and the Andes of South America.[2]
Description
Basaltic andesite is a fine-grained (
Although classification by mineral content is preferred by the
A basaltic andesite (or andesite) enriched in
Occurrence
Basaltic andesite is found in volcanic arcs, such as those of Central America,[1] the Andes of South America,[2] and the Cascades of North America.[7]
Basaltic andesite is also common where the Earth's crust is undergoing extension. For example, mid-Cenozoic volcanic sequences in western Mexico, southwestern New Mexico, and southeastern Arizona are capped by basaltic andesite of the Southern Cordilleran Basaltic Andesite (SCORBA) suite, which may be the most extensive Cenozoic mafic suite in North America.[8] Mount Mazama, a large composite volcano in south-central Oregon, consists of several overlapping basaltic andesite shields.
Basaltic andesite is a component of back-arc basin basalt suites.[9] The Columbia River Basalt Group is composed of 80% basaltic andesites on the basis of silicon content.
Thick sequences of basaltic andesites were erupted in a shallow-marine environment during the
The Mars Global Surveyor has found evidence for basaltic andesite on Mars.[11]
References
- ^ a b Jordan, B.R.; Sigurdsson, H.; Carey, S.; Lundin, S.; Rogers, R.D.; Singer, B.; Barquero-Molina, M. (2007). "Petrogenesis of Central American Tertiary ignimbrites and associated Caribbean Sea tephra". In Mann, Paul (ed.). Geologic and tectonic development of the Caribbean plate boundary in northern Central America. Geological Society of America. p. 161.
- ^ a b Kay, Suzanne Mahlburg; Copeland, Peter (2006). "Early to middle Miocene backarc magmas of the Neuquén Basin: Geochemical consequences of slab shallowing and the westward drift of South America". In Kay, Suzanne Mahlburg; Ramos, Victor A. (eds.). Evolution of an Andean margin: a tectonic and magmatic view from the Andes to the Neuquén Basin (35 degrees-39 degrees S lat). Geological Society of America. p. 209.
- ISBN 9780195106916.
- ^ ISBN 9780521880060.
- ISBN 0877353239.
- ISBN 978-1292021539.
- .
- .
- ^ Gaetani, Glenn A.; Grove, Timothy L.; Bryan, Wilfred B. (1994). "Experimental phase relations of basaltic andesite from hole 839B under hydrous and anhydrous conditions". Proceedings of the Ocean Drilling Program, Scientific Results. 135.
- .
- S2CID 10265805.