Definition of extrusive in US English:



  • Relating to or denoting rock that has been extruded at the earth's surface as lava or other volcanic deposits.

    • ‘The presence of extrusive volcanic rocks during the rifting stages suggests that a large volume of melt may also have been added to the crust intrusively.’
    • ‘Although there are no outcrops of Devonian extrusive volcanic rocks in NW Scotland, they can be found in southern and central Scotland and the Orkney Islands.’
    • ‘On the basis of geochemical analysis and field studies the extrusive volcanic rocks are generally interpreted as being associated with crustal extension.’
    • ‘In practice pyroclastic and volcaniclastic rocks include all the products of extrusive volcanic activity except lava flows.’
    • ‘The northern margin of the melange is marked by a thrust contact with both the Carboniferous sedimentary rocks and extrusive volcanic sequence.’
    sticking out, protuberant, protruding, prominent, jutting, jutting out, overhanging, standing out, proud, bulging, bulbous
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