Dacite information

Dacite (/ˈdeɪsaɪt/) is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained...

although the majority are of intermediate composition (such as Santiaguito, dacite-andesite, present day) The characteristic dome shape is attributed to high...

called the Pagosa Peak Dacite, made of dacite that is very similar to that of the Fish Canyon Tuff. The Pagosa Peak Dacite, which has characteristics...

ranges from 63 to 69 percent. The dacite volcanic plugs, lava domes, intrusive sheets, and felsitic rhyolite-dacite between Morro Rock and Islay Hill...

(611 m), about 1,400 feet (430 m) above the flat prairie. This Pleistocene dacite lava dome is part of the Cascade Volcanic Arc, and with an age of only about...

is dacite. The columns, or pipes, were formed in the later stages of Mount Boucherie's volcanic period, as evidenced by the fact that the dacite columns...

Rhyodacite is a volcanic rock intermediate in composition between dacite and rhyolite. It is the extrusive equivalent of those plutonic rocks that are...

erupt from the vent were hornblende-pyroxene andesites with a hornblende dacite dome at its summit. Glacial erosion has since modified its shape.[citation...

often felsic, having high to intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less viscous mafic magma. Extensive...

percentage (>63%) of silica, the lava is described as felsic. Felsic lavas (dacites or rhyolites) are highly viscous and are erupted as domes or short, stubby...

basalt, ferro-basalt, tholeiitic basaltic andesite, tholeiitic andesite, dacite and rhyolite. The variety of basalt in the series was originally called...

'slate' or 'bluestone', a metamorphic phyllite rock, with both andesite and dacite mineral composition. Dacitic phyllite is a predominant type of rock found...

smaller dacite domes formed around Lassen. The largest of these, Chaos Crags, is just north of Lassen Peak. Phreatic (steam explosion) eruptions, dacite and...

rich in silica extrusive rock obsidian and sometimes dacite domes form the extrusive rock dacite, like in the case of Mount St. Helens. Calderas are volcanic...

Monte Amiata, Tuscany Glynn Hill, County Antrim, Northern Ireland Scafell Dacite (including Great Gable), Cumbria, England Skerry Fell Fad, Argyll and Bute...

which converts (devitrification) the volcanic glass (obsidian, rhyolite, dacite) present in the ash into clay minerals. In the mineral alteration process...

containing orthopyroxene Enderbite – Igneous rock of the charnockite series Dacite – Volcanic rock intermediate in composition between andesite and rhyolite...

lava flows and lava domes. The volcano's eruptions have produced mostly dacite along with andesite and rhyolite. Past glaciation has left moraines on Guallatiri...

corner of the Long Valley Caldera and consists of about 12 rhyodacite and dacite overlapping domes. These domes formed in a long series of eruptions from...

then, smaller dacite domes such as the 1,100-year-old Chaos Crags have formed around Lassen. Phreatic (steam explosion) eruptions, dacite and andesite...

Mazama has produced 43 percent rhyodacite, 42 percent andesite, 15 percent dacite, and less than 1 percent basaltic andesite. All of the rhyodacite has been...

Esprit, and Mt. Grand Magazin, all greater than 1 Ma in age. Andesitic and dacite pyroclastic flows from these volcanoes are found at Morne Tabac dome (532...