Trachyandesite is an extrusive igneous rock with a composition between trachyte and andesite. It has little or no free quartz, but is dominated by sodic...

targets – Basaltic lava with a flowing, often ropy appearance Basaltic trachyandesite – Naming system for volcanic rocksPages displaying short descriptions...

Trachybasalt. S2 (Basaltic trachyandesite)—*Sodic and potassic variants are Mugearite and Shoshonite. S3 (Trachyandesite—*Sodic and potassic variants...

example in the intrusive dioritic pluton of El Teniente, Chile and in trachyandesite pumice erupted by El Chichón volcano, Mexico. The name anhydrite was...

mafic compositions. Typical intermediate rocks include andesite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks...

basalt-trachybasalt-trachyandesite volcanoes (Ngorongoro also contains trachydacite) and the 1.6-1.5 Ma Oldeani basalt-trachyandesite volcano. The highlands...

rock. More specifically, it is a potassium-rich variety of basaltic trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass...

identified as plagioclase basalt, but now reclassified as basaltic trachyandesite to trachyandesite. The third phase, from 2.75 to 2.52 million years ago, completed...

Andesite Alkali feldspar granite Anorthosite Aplite Basalt Basaltic trachyandesite Mugearite Shoshonite Basanite Blairmorite Boninite Carbonatite Charnockite...

plagioclase-bearing basaltic trachyandesite flows Hog Pen Formation: interbedded debris flows and basalt to basaltic trachyandesite flows These rest on the...

alkaline rocks atypical for oceanic islands, ranging from basalt through trachyandesite and trachyte to rhyolite. Ascension has a hot desert climate (BWh, according...

fields, such as the trachyandesite field, are further classified by the ratio of potassium to sodium (so that potassic trachyandesites are latites and sodic...

have calderas. Ngorongoro Volcano (2.5–1.9 Ma) is primarily basaltic trachyandesite. The caldera is fed by the Munge and Oljoro Nyuki Rivers, while the...

sediments and volcanic rocks. The volcanics consist of rhyolite, basalt, trachyandesite, and trachyrhyolite. Uranium ore bodies are found in the Dornod, consisting...

as an eruption at Ojos del Salado in 1993. The volcano has erupted trachyandesite and trachydacite in the later stages of activity, after a stage with...

Pozzolana containing significantly less volcanic glass, such as a trachyandesite from Volvic (France) with only 25 wt% are less reactive. Apart from...

is the tephra of Deception Island, which is of trachyte and basaltic trachyandesite, richer in potassium and sodium. Quaternary volcanic products of the...

5,000 years ago.[citation needed] The island consists primarily of trachyandesite rock. A major explosive eruption around 8000 BCE decapitated its top...

along ring faults associated with caldera collapse. Rock types include trachyandesite, trachyte, syenite and amphibole - biotite granite. They are commonly...

trachyandesite was interpreted as lacustrine, likely the result of ponding against the volcanic flows. The high relative abundance of trachyandesite and...

an estimated VEI of 7. An estimated 41 km3 (10 cu mi) of pyroclastic trachyandesite were ejected, weighing about 10 billion tonnes. This left a caldera...

phonolite Jabal Arknu Libya Tertiary Otoge Japan Miocene alkali basalt, trachyandesite Zarza Mexico Cretaceous gabbro Houshihushan China Cretaceous granite...

million years ago, above an accumulation of several layers of pyroclastic trachyandesite. The summit is accessible from the ski resort of Super Lioran by a cable...

descended over steep slopes. Tambora has produced trachybasalt and trachyandesite rocks which are rich in potassium. The volcanics contain phenocrysts...

Red Sea region, Eritrea Geology Mountain type Stratovolcano Type of rock Rhyolite, Basalt, Andesite, Trachyandesite and Trachyte Last eruption Unknown...

olivine phenocrysts. This first cone is lengthened to the north by the trachyandesite tuff ring which caused its obstruction. These projections are dark and...

Huechulafquen. This cone has three craters. A tephra layer of black trachyandesite has been linked to Huanquihue and is dated 4028-4212 BP. Varve count...

deposited dacite, rhyolite and ignimbrite, as well as trachyte and trachyandesite. This trend towards the production of more felsic, viscous lavas could...

Cantal massif, Puy Chavaroche is composed of alternating layers of trachyandesite and volcanic breccias. Puy Chavaroche can be reached on foot from the...

million years before present. The volcano's rock type is principally trachyandesite. K-Ar dating of about 1.14 million years was obtained from the Amorong...