GG231 Lecture 2: GG231 LECTURE 2
Document Summary
Tectonic: large scale geologic processes that deform earth"s lithosphere and produce ocean basins, continents, and mountains. Tectonic forces are driven by forces deep within earth movement of lithospheric plates. The lithosphere is broken up into large pieces called lithospheric plates that move relative to one another. Plate tectonics: processes involved in the creation, movement, and destruction of these plates. Seafloor spreading is the mechanism for plate tectonics. Continental drift: the idea that continents move proposed by alfred wegener in 1915. Seafloor spreading: new crust is continuously added to the edges of lithospheric plates at mid- ocean ranges or spreading centres. Oceanic lithosphere is added at spreading centres but destroyed when one plate sinks below another at sites called subduction zones. There are three types of boundaries: divergent, convergent, and transform. Divergent boundaries: occur when two plates move away from each other and new lithosphere is created. Typically this process occurs at mid-ocean ridges and the process is called seafloor spreading.
