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THE ROCK CYCLE |
![](ROCK CYCLE/rock_cycle_nasa.gif) The rock cycle illustrates in a schematic fashion the interrelationships between earth materials and processes. On this web page, one possible 'journey' around the cycle will be examined. The journey will start with a volcanic eruption. (After NASA diagram.) |
IGNEOUS ROCKS - VOLCANIC |
![](buttonon_red.gif) Click on the red button to see a volcano erupt. |
![](ROCK CYCLE/Cascadex.jpg) Erupting lava. |
![](ROCK CYCLE/Domex.jpg) Erupting lava. |
![](ROCK CYCLE/Curtainx.jpg) Erupting lava. |
![](ROCK CYCLE/ropy_aa_614.jpg) Cooling lava. |
![](ROCK CYCLE/craters_moon_16.jpg) Cooled lava - Volcanic rock. |
![](ROCK CYCLE/craters_moon_13.jpg) Foreground: cooled lava. Background: loose volcanic cinders. |
![](ROCK CYCLE/craters_moon_8.jpg) Loose volcanic cinders. |
![](ROCK CYCLE/craters_moon_18.jpg) Rough-surfaced volcanic lava rock. |
![](ROCK CYCLE/lassen_6.jpg) Volcanic glass. |
![](ROCK CYCLE/parump_2.jpg) Poorly consolidated volcanic ash. |
IGNEOUS ROCKS - INTRUSIVE |
![](ROCK CYCLE/pbppgx2.jpg) Igneous intrusion (pink) cutting across metamorphic rock. |
![](ROCK CYCLE/acadia_71.jpg) Molten magma intruded into metamorphic rock (dark brown) has cooled to form cross-cutting igneous bodies (speckled light orange). |
![](ROCK CYCLE/maine_73 copy.jpg) Detail of magma that has cooled to form granite. Note the orange, white, grey and black minerals that constitute the granite. |
WEATHERING |
![](buttonon_red.gif) Click on the red button to see a rock broken apart by frost action. |
![](ROCK CYCLE/dorset_3.gif) Chalk bedrock (white) has weathered to loose chalk fragments and dark soil. |
![](ROCK CYCLE/grand_canyon_74.gif) A weathered boulder begins to fall apart. |
![](ROCK CYCLE/joshua_tree_10,11x.gif) Weathered granite (top photo) falls apart at the touch (bottom photo). |
TRANSPORT |
LANDSLIDES |
![](ROCK CYCLE/gc_50.gif) A cliff gradually disintegrates. The pieces of rock fall to the valley floor. |
WIND TRANSPORT |
![](ROCK CYCLE/great_dunes_93.gif) Wind blown sediment accumulates as sand dunes. |
![](ROCK CYCLE/white_s_11.gif) Wind blown sediment accumulates as sand dunes. |
![](ROCK CYCLE/sinai_5.gif) Wind blown sediment accumulates as sand dunes. |
STREAM TRANSPORT |
![](ROCK CYCLE/misc_14.gif) A stream laden with suspended milky colored sediment flows into a clear stream. |
![](ROCK CYCLE/klamaths_8.gif) Cobbles and pebbles line the bottom of a mountain stream. After a storm, when the stream is in flood, the cobbles and pebbles will be moved downstream. |
![](ROCK CYCLE/arches_70.gif) During low water time, the sediment this stream was carrying temporarily comes to rest in the channel. |
GLACIAL TRANSPORT |
![](ROCK CYCLE/glac001845.jpg) Glacial ice carries along sediment that has fallen onto it from nearby mountain slopes. |
![](ROCK CYCLE/glac1515.jpg) Glaciers are capable of carrying huge boulders. |
![](ROCK CYCLE/catskills_45.jpg) This mountainous area was once covered by a great thickness of glacial ice. As the ice melted away, a boulder that it was carrying was lowered down onto this mountain top. |
![](ROCK CYCLE/mt_rainier_51.jpg) As glacial ice melts, the sediment the ice was carrying is lowered to the ground. |
TRANSPORT BY LIVING ORGANISMS |
![](ROCK CYCLE/dozer_dump.gif) Living organisms, such as people, insects and worms transport huge amounts of sediment every year. |
SEDIMENTARY ROCKS |
![](ROCK CYCLE/olympic_27.gif) Loose pebbles. |
![](ROCK CYCLE/aspen_10.gif) Pebbles cemented to become rock. |
![](ROCK CYCLE/olympic_77.gif) Underwater ripple marks in sand. |
![](ROCK CYCLE/rosendale_8.gif) Ripple marks turned into rock. |
![](ROCK CYCLE/sayerville_2.gif) Wind deposited sand. |
![](ROCK CYCLE/zion_1.gif) Wind deposited sand turned to rock. |
![](ROCK CYCLE/badlands_22.gif) Layered sedimentary rocks. |
![](ROCK CYCLE/angels_peak_3.gif) Layered sedimentary rocks. |
DEFORMATION |
![](ROCK CYCLE/cornwall_bude_125.gif) Deformed sedimentary rocks. |
![](ROCK CYCLE/north_shore_26 copy.jpg) Sedimentary rocks that have been somewhat altered by heat and highly deformed. |
METAMORPHIC ROCKS |
![](ROCK CYCLE/gneiss4.gif) Rock that has been extensively altered by heat and pressure. |
![](ROCK CYCLE/gn_aug1.gif) Rock that has been extensively altered by heat and pressure. |
MELTING |
![](ROCK CYCLE/Cascadex.jpg) Under conditions of high hear and pressure, metamorphic rock my be melted to form magma. That magma may be erupted to the surface as lava. |
![](ROCK CYCLE/rock_cycle_nasa.gif) One 'journey' around the rock cycle has been completed: magma cools to form igneous rocks (volcanic and intrusive); the rocks are weathered to loose material; the loose material (sediment) is transported and then deposited. The sediment turns into sedimentary rock. The sedimentary rock is squeezed and baked to form metamorphic rock. The metamorphic rock then melts to form new magma, and the cycle is ready to repeat. (After NASA diagram.) |