Earth consists of a solid, mostly iron inner core; a liquid, mostly iron outer core; a crystalline but largely plastic mantle; and a rocky, brittle crust.
Earth’s lithosphere is divided into plates that are in motion with respect to one another. The lithosphere is composed of the crust and upper portion of the mantle. There are two different types of lithospheres — oceanic and continental — that have very different physical and mineralogic characteristics. The ocean lithosphere is relatively thin, young, and dense. The continental lithosphere is relatively thick, old, and less dense.
Most large scale, high-energy events of geologic activity (e.g., earthquakes, volcanoes, and mountain building) occur as a result of relative motion along plate boundaries.
Plate motion occurs as a consequence of convection in Earth’s mantle, including upwelling of material from the deep mantle in rift zones, the lateral movement of tectonic plates, and the sinking dense, old plates at subduction zones
integrate the rock cycle with Plate Tectonics Theory and determine how this is reflected in the geology of Virginia’s five physiographic provinces.
analyze the formation of fossil fuels in terms of the rock cycle and Plate Tectonics Theory, and relate the formation of fossil fuels to ancient biologic and atmospheric conditions and changes and locations within Virginia.
Virginia has five physiographic provinces produced by past episodes of tectonic activity and continuous geologic activity.
integrate and interpret the rock cycle, plate tectonics, and Virginia’s geology in an interacting diagram.
analyze how multiple continental collisions and rifting events over the last billion years have created the current physiography of Virginia.
comprehend and apply the details of Plate Tectonics Theory to the formation of continents, mountain chains, island arcs, deep open trenches, earthquake zones, and continental and mid-ocean volcanism.
analyze the composition and structure of the continental and oceanic lithosphere in terms of topographic features, density, thickness, and rates of motion.
compare and contrast various types of volcanism and geothermal activity (i.e., Hawaii, Iceland, Mount St. Helens, Catoctin Greenstone, Tambora, the Deccan Traps, and Yellowstone).
compare and contrast different types of current and ancient plate boundaries (i.e., Japan, California, New Madrid, Missouri, the Appalachian system, Iceland, and Tonga).
Relative plate motions and plate boundaries are convergent (subduction and continental collision), divergent (seafloor spreading), or transform. Major features of convergent boundaries include collision zones (folded and thrust-faulted mountains) and subduction zones (volcanoes and trenches). Major features of divergent boundaries include mid-ocean ridges, rift valleys, fissure volcanoes, and flood lavas. Major features of transform boundaries include strike-slip faults.
Earthquake activity of varying energy levels and depths is associated with all plate boundaries.
analyze the body of evidence for Plate Tectonics Theory (i.e., seafloor age, magnetic information, seismic profiles, laser-measured motion studies, fossil evidence, rock types associated with particular tectonic environments).
analyze the various structures produced in convergent plate boundaries.
offer interpretations of the tectonic history of an area based on the range and type of rocks found in that area.
compare and contrast the tectonic activity of the east coast and the west coast of North America.