Volcanoes and Other Igneous Activity

Volcanoes and Other Igneous Activity 1) ________ is a major dissolved volatile constituent in both magmas and volcanic gases. A) Water B) Carbon monoxide C) Hydrogen chloride D) Methane 2) Which type of basaltic lava flow has a fairly smooth, unfragmented, ropy surface? A) aa B) pegmatitic C) pahoehoe D) scoria 3) In 1980, ________ was the first Cascade Range volcano to erupt since Mt. Lassen in 1915-16. A) Mt. Rainier B) Mt. Shasta C) Kilauea D) Mt. St. Helens 4) The ________ ocean basin is rimmed by the most subduction zones. A) Atlantic B) Indian C) Pacific D) Arctic 5) Cinder cones ________. A) have very steep slopes B) are usually less than 300 meters (1000 feet) high C) consist largely of pyroclastics D) all of these 6) ________ are usually the most abundant gases emitted during basaltic volcanism. A) Chlorine and sodium B) Neon and ammonia C) Oxygen and nitrogen D) Water and carbon dioxide 7) Mount Pel?e on Martinique is an example of a ________. A) shield volcano B) cinder cone C) lava dome D) composite volcano 8) ________ tend to increase the explosive potential of a magma body beneath a volcano. A) High viscosity and dissolved gas B) High viscosity, low dissolved gas content C) Low silica content, low viscosity D) Low viscosity, low dissolved gas content 9) ________ destroyed the city of St. Pierre, Martinique, in 1902. A) Mudflows B) Basaltic lava flows C) Heavy ashfall D) A nue? ardente 10) Which kind of eruptive activity is most likely to be highly explosive? A) lava flows from a large shield volcano on an oceanic island B) fissure eruptions feeding lava to flood basalt accumulations C) eruptions of big, continental margin, composite cones or stratovolcanoes D) lava flows from a large cinder cone complex 11) Kilauea and Mauna Loa are ________. A) explosive, rhyolitic volcanoes B) andesitic stratovolcanoes C) basaltic shield volcanoes D) small, basaltic cinder cones 12) A ________ is an intrusive, igneous rock body that is tabular and concordant. A) laccolith B) dike C) pluton D) sill 13) Which region has the greatest concentration of currently active volcanoes? A) the coastal plain of western Africa B) European Russia and Siberia C) the area surrounding the Red Sea D) the circum-Pacific area 14) The recent (geologically) volcanic activity in Yellowstone National Park is ________. A) related to plate subduction B) related to a divergent plate boundary C) related to a transform plate boundary D) related to intraplate, hot spot volcanism 15) Spreading center volcanism most generally produces rocks that are ________. A) granitic in composition B) basaltic in composition C) rhyolitic in composition D) ultramafic in composition 16) A ________ is a near-surface, intrusive igneous rock body that results from local inflation of a horizontal sill, giving it a mushroom-shaped dome-like top. A) batholith B) dike C) laccolith D) volcanic neck 17) Volcanic bombs originate ________. A) as laser-guided, granite blocks launched from a supersonic jet B) as blocks of volcanic rock ejected from an erupting volcanic crater C) as erupted magma blobs that partly congeal before falling to the ground D) as ash particles that join together in the eruptive plume and fall as cobble-sized objects 18) Paricutin is an example of a ________. A) shield volcano B) cinder cone C) lava dome D) composite volcano 19) Which type of basaltic lava flow has its surface covered with sharp-edged, angular blocks and rubble? A) scoria B) pahoehoe C) pillow lava D) aa 20) Most of the active volcanoes on Earth are located in a belt known as the ________. A) Ring of Fire B) Gulf Coast Zone C) Mid-Pacific Ridge D) Red Sea rift