Breccia — (pronEng|ˈbrɛtʃiə, ˈbrɛʃiə, it. breach) is a rock composed of angular fragments of several minerals or rocks in a matrix, that is a cementing material, that may be similar or different in composition to the fragments. A breccia may have a variety … Wikipedia
breccia — /brech ee euh, bresh /, n. Petrol. rock composed of angular fragments of older rocks melded together. [1765 75; < It < Gmc; cf. OHG brecha breaking] * * * Coarse sedimentary rock consisting of angular or nearly angular fragments larger than 0. 08 … Universalium
volcanic neck — noun : a column of igneous rock that is formed by congelation of lava or the consolidation of volcanic breccia in the conduit of a volcano and that may later be left standing above the adjacent country by the removal of surrounding rocks by… … Useful english dictionary
Volcanic glass — A sand grain of volcanic glass under the petrographic microscope. Its amorphous nature makes it go extinct in cross polarized light (bottom frame). Scale box in millimeters. Volcanic glass is the amorphous (uncrystallized) product of rapidly… … Wikipedia
volcanic cone — noun : a conical mountain or hillock built up of cinders, tuff, breccia, and lava by volcanic eruptions * * * Geol. a conical hill produced by volcanic eruption of ash, cinders, or lava. Cf. cinder cone. * * * volcanic cone, a hill around the rim … Useful english dictionary
volcanic dome — ▪ geology also called Lava Dome, any steep sided mound that is formed when lava reaching the Earth s surface is so viscous that it cannot flow away readily and accumulates around the vent. Sometimes domes are produced by repeated outpourings… … Universalium
Geology of the Lassen volcanic area — The geology of the Lassen volcanic area presents a record of sedimentation and volcanic activity in the area in and around Lassen Volcanic National Park in Northern California, U.S.. The park is located in the southernmost part of the Cascade… … Wikipedia
flow breccia — Petrol. a volcanic breccia that has solidified from a lava flow. * * * … Universalium
flow breccia — Petrol. a volcanic breccia that has solidified from a lava flow … Useful english dictionary
Back River volcanic complex — The Back River volcanic complex is an Archean stratovolcano, located km to mi|num=480|abbr=no|spell=Commonwealth|precision=0|wiki=yes northwest of Yellowknife, Northwest Territories, Canada. The volcano constitutes the Back Group of the… … Wikipedia