dacitic magma is highly viscous.    From Wordnet, Princeton University. 

The andesitic-dacitic volcano was constructed within a 10-km-wide caldera.    From Wordnik.com.  [Volcanic Activity Appears To Be Working It's Way Around The "Ring of Fire"] Reference

The peaks are the degraded dacitic cores of two lava-dome volcanoes probably formed on the side of a collapsed andesitic strato-volcano.    From Wordnik.com.  [Pitons Management Area, Saint Lucia] Reference

The eastern half of Guadeloupe is called Grande Terre and is composed entirely of limestone overlying older andesitic and dacitic volcanics.    From Wordnik.com.  [Leeward Islands xeric scrub] Reference

Six widespread tephras ~0.1–1.0 cm thick with rhyolitic to dacitic glass and/or phenocrysts of feldspar or hornblende are preserved in the glacial lakes of Las Cajas National Park, southern Ecuador.    From Wordnik.com.  [Tephras in Ecuador « Climate Audit] Reference

The main veins trend northwest, dip to the northeast and are hosted within Miocene age dacitic volcanic rocks.    From Wordnik.com.  [ACN Newswire] Reference

Native GOLD in dacitic to rhyodacitic metavolcanic rocks and graphitic schists, associated with native antimony, minor arsenopyrite and pyrrhotite.    From Wordnik.com.  [Marketwire - Breaking News Releases] Reference

(1974 eruptions of Fuego and Pacaya) and dacitic (1969, 1975 and 1976 eruptions of Santiaguito, Guatemala, and 1980 eruption of Mount St. Helens, U.S.A.).    From Wordnik.com.  [volcanic ash hazards and ways to minimize them] Reference

Residual vuggy silica occurrences are localized by a broader overprint of silica ± alunite, within ubiquitously argillic to advanced argillic altered rhyo-dacitic pyroclastics.    From Wordnik.com.  [Marketwire - Breaking News Releases] Reference

The major exposed rocks in the Dadi Property are Upper Jurassic Baiyinggaolao Formation dacitic tufaceous lava, dacitic tuff, rhyolitic tuff, and tufaceous sendstone and conglomerate, among which dacitic tufaceous lava and dacitic tuff are the main host rocks of mineralization.    From Wordnik.com.  [News] Reference

The samples collected were representative of the several styles of mineralisation already identified within the Seinajoki Project, including: a. Native GOLD in dacitic to rhyodacitic metavolcanic rocks and graphitic schists, associated with native antimony, minor arsenopyrite and pyrrhotite.    From Wordnik.com.  [The Earth Times Online Newspaper] Reference