Dacite - Wikipedia
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 (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. It is composed predominantly of plagioclase feldspar and quartz.
Dacite: An extrusive igneous rock of the continental crust. - Geology.com
Dacite is a fine-grained igneous rock that is normally light in color. It is often porphyritic. Dacite is found in lava flows, lava domes, dikes, sills, and pyroclastic debris. It is a rock type usually found on continental crust above subduction zones, where a …
Dacite: A Fine-grained, Light-Colored Volcanic Rock
2023年9月14日 · Dacite is a fine-grained, light-colored volcanic or extrusive igneous rock. Its composition is felsic and mainly has plagioclase feldspar, quartz, lesser alkali feldspar, minor hornblende, biotite, and other mafic minerals. Plagioclase is more alkali feldspar in this rock. Guido Stache, an Austrian geologist, proposed the term dacite in 1863.
Dacite: Identification, Pictures, & Info for Rockhounds
Dacite forms when viscous, felsic lava rapidly cools at or near the Earth’s surface, negating the opportunity for the formation of large crystals in the groundmass. This most commonly occurs in volcanic arcs associated with subduction zones but also occurs in hot spots and other settings.
Dacite | Volcanic, Igneous, Magma | Britannica
Dacite, volcanic rock that may be considered a quartz-bearing variety of andesite. Dacite is primarily associated with andesite and trachyte and forms lava flows, dikes, and sometimes massive intrusions in the centres of old volcanoes.
USGS: Volcano Hazards Program Glossary - Dacite
Dacite lavas are viscous and tend to form thick blocky lava flows or steep-sided piles of lava called lava domes. Dacitic magmas tend to erupt explosively, thus also ejecting abundant ash and pumice.
Dacite - an overview | ScienceDirect Topics
The host rock is dacite –quartz-feldspar porphyry intruded into volcanic andesite, andesite breccia, conglomerate, sandstone, and tuff. The basement rocks are granite, schist, and gneiss.
Rock Identification with Willsey: Volcanic Rocks (andesite, dacite ...
Learn to identify and describe andesite, dacite, and rhyolite (three common volcanic rocks) with geology professor Shawn Willsey. Part of my ongoing series on some easy and practical ways to...
Dacite - ALEX STREKEISEN
Dacite, from Dacia, a Roman province, Transylvania, Romania, is a volcanic rock that may be considered a quartz-bearing variety of andesite. Dacite is primarily associated with andesite and trachyte and forms lava flows, dikes, and sometimes massive intrusions in …
Dacite - Encyclopedia.com
2018年5月8日 · Dacites are the volcanic equivalents of granodiorites and are found as members of the calc-alkaline series, typically developed as eruptive products on the continental side of oceanic-continental plate subduction zones. They are often surprisingly coarse-grained for lavas. Pick a style below, and copy the text for your bibliography.
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