| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 3,909,719,549 visitors served. |
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
Dacite |
Also found in: Dictionary/thesaurus, Wikipedia | 0.03 sec. |
|
|
dacite [′dā‚sīt]
(geology) Very fine crystalline or glassy rock of volcanic origin, composed chiefly of sodic plagioclase and free silica with subordinate dark-colored minerals. Dacite a magmatic rock that is the effusive equivalent of granodiorite and quartz-diorite. Dacite consists of a finegrained or vitreous basic mass and phenocrysts of plagioclase and quartz, more rarely, of hornblende, biotite, and pyroxene, and sometimes, sanidine. Where albitization processes are widely developed, dacite turns into quartz al-bitophyre. Dacites were ejected by volcanoes in the Paleozoic (in the Urals, for example), Mesozoic, and Cenozoic (in the Caucasus, for example). They are also found among modern lavas on Kamchatka. Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
|
| Encyclopedia |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup |
|---|