Chapter 9 Volcanoes And Volcanic Landforms Flashcards
The largest fl ood basalt of all – includes both marine and continental deposits distributed throughout the Atlantic Ocean margins recording the break - up of the Pangea supercontinent
the Central Atlantic Magmatic Province (CAMP) –
are the youngest fl ood basalt deposits on Earth, having erupted within the past 17 Ma
The Columbia River/Snake River Plain flood basalts
represent rare examples of ocean ridges exposed above sea level due to unusually large volumes of erupted lava; these ocean islands represent regions where hotspots locally underlie the spreading ridge system.
Iceland, the Galapagos Islands and the Azores Islands
represent rare examples of ocean ridges exposed above sea level due to unusually large volumes of erupted lava; these ocean islands represent regions where hotspots locally underlie the spreading ridge system.
Iceland, the Galapagos Islands and the Azores Islands
Ontong Plateau deposits in the western Pacifi c Ocean basin and the Kerguelen Plateau in the Indian Ocean
Oceanic flood Plateau
white smokers that emit lower temperature (100 – 300 ° C) solutions that precipitate light - colored minerals such as
calcite, gypsum, barite and quartz.
are steep - sided ( ∼ 30 – 35 ° ) conical features composed of tephra
Pyroclastic cones
Steepness of shield volcanoes
2-10
Pyroclastic cones include:
Cinder and scoria cones
consisting of ash, lapilli and bomb - sized particles of various composi-tions that accumulate as circular to oval - shaped conical volcanoes
Cinder cones
composed predominantly of vesicular basaltic material
Scoria cones
consist of alternating layers of pyroclastic debris and lava fl ows that build volcanic cones.
Composite volcanoes
Block lavas lithify as volcanic breccia deposits. T or f
T
consists of smooth - sided blocks up to several meters in diameter that tumble downslope
Block lava
are steep - sided, blister - like forms that occur within volcanic craters
Domes
