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GL1 II KI 3c The various elements of the rock cycle may be linked directly to plate tectonic processes: (i) IGNEOUS – basaltic magmatism at oceanic spreading centres and island arcs (ii) SEDIMENTARY – erosional processes and depositional environments (iii) REGIONAL METAMORPHISM – in subduction and orogenic belts Rock cycle The rock cycle turns Everest mountains into rock fragments by erosion and weathering http://www.youtube.com/watch?v=nIfJouzUmno&feature=related Plate tectonics BUILD at constructive plate boundaries DESTROY at convergent plate boundaries IGNEOUS – constructive plate boundary Partial melt of upper mantle material at constructive plate boundaries Produces BASALTIC magma, silica poor, runny magma IGNEOUS – convergent plate boundary Ocean : Ocean and ocean:continent collision Partial melting of subducted oceanic plate and overlying mantle rocks Produces ‘BASALT’ and ANDESITE silica rich ... Thick sticky magma ....explosive SEDIMENTARY Erosional processes and depositional environments are influenced by tectonic movements Uplift by compression eg. faults and folds Renews erosional surfaces New mountains (OROGENIC BELT) are built (OROGENESIS) at convergent boundaries to be eroded METAMORPHISM Convergent plate boundaries Partial melting of subducted crust and overlying rocks Produces: REGIONAL METAMORPHISM in the orogenic belt and GRANITE plutons at depth Websites: www.platetectonics.com/index.htm www.platetectonics.com/TharpeHeezen/index.htm http://dl.ccc.cccd.edu/classes/telecourses/geol ogy100/IntroLecture2.htm http://pubs.usgs.gov/of/1999/ofr-99-0132/