Largely composed of liquid iron The source of the Earth’s liquid iron The source of the Earth’s magnetic field A low viscosity fluid that is in rapid convection Entirely composed of MgSiO3 in the mineral structure of perovskite 93% of the chemical elements that comprise the Earth could be modelled by the mineral olivine with a 1:1 magnesium-iron ratio. What is the Mg:Fe ratio of the olivine xenoliths that are brought to the surface in basaltic lava flows? Mg: Fe= 1:1 Mg: Fe= 3.2 Mg: Fe=1.2 Mg: Fe-1.9 Mg: Fe= 9.1 Which of these simple models best describes Earth’s interior structure? A thin rocky crust underlain by a silicate mantle which overlies a fluid iron core with a solid iron core at the centre. The two most common gasses of Earth’s atmosphere and their percentages are: Nitrogen (N 2 ), 78%, and Oxygen (0 2 ), 21% Choose the list that shows rock composition decreasing in silica and increasing in iron and magnesium. Granite, peridotite, basalt Basalt, peridotite, granite
The question is invalid; they’re all equally rich in iron and magnesium Granite, basalt, peridotite Peridotite, basalt, granite Identify the FALSE statement: The Moho marks the boundary between the mantle and the core Ocean crust is denser than continental crust Continental crust can be four times as thick as ocean crust Ocean crust consists of basalt and gabbro; continental crust consists of a great variety of rock types Continental crust is less mafic than ocean crust (The Moho is the boundary between the mantle and the crust) Which of the following is caused by the interaction of the solar wind with magnetic lines of force and gases in polar regions? The aurorae Roughly 50% of Earth’s surface is covered by oceans and seas. False Iron, Oxygen, Silicon, and Potassium make up most of the mass of the whole Earth False (Magnesium, not Potassium) A rock is a solid organic substance in which atoms are arranged either in an orderly pattern (crystalline) or as irregularly shaped grains; a mineral is an aggregate (mixture) of rocks. False Basalt and gabbro are fine-grained mafic rocks FALSE: basalt is fine-grained and mafic, but gabbro is coarse-grained and mafic. The Kola Peninsula deep hole is the deepest well ever drilled. It penetrates halfway through the continental crust. False—it penetrated a third of a way through the Baltic continental crust Sudden fracture of rocks and rapid movements along faults cause earthquakes
True The core amounts for most of the volume of the earth False. The mantle accounts for most of the volume of the Earth Earth's core is known to be dense and thought to be mostly composed of iron, nickel with small quantities of oxygen, sulphur, silicon and carbon. What proportion of Earth's mass is contained within the core?
- Fall '09
- Plate Tectonics, north american plate, Basalt