Flashcards
Geological processes
Cards in this deck (10)
- 1The importance of processes that produce local concentrationsThe mineral is a specific compound. Elements are found at widely varied concentrations. Geological processes localised higher purity deposits.
Continental drift two tectonic plates: tinner oceanic and thick continental. Plates float of the denser semi-molten mantle below. Heat in the mantle, generated by radioactive decay which causes convection currents which move the heat around. Friction then causes continental drift. - 2The importance of processes that produce local concentrations - continuedCollision between oceanic and continental: thicker continental plate ride over thinner oceanic. Friction creates heat which produces volcanic activity. Friction can also cause the crust to crumple which produces mountain ranges.
Collision of two continental plates: convection currents in mantle cause movement of plates towards each other, mountain ranges created.
When two oceanic plates move away from one another mantle rises up through the gap and solidifies creating new rust. - 3Three types of rockIgneous - solidification of molten magma
Sedimentary - deposition of material at the surface
Metamorphic - intense heat and pressure on existing rocks - 4Igneous procceses - extrusionExtrusive rocks formed above the surface, basalt for example. Magma cools above hr surface, rapid cooling. Produces small crystals.
- 5Igneous rocks - intrusionsFormed beneath the surface when magma solidifies slowly. Causes large crystals. An example is granite. Hydrothermal deposition: Hot rocks heat water which dissolves minerals in it. Mineral-rich solutions cool and solidify as they crystallize. Metal ores that are deposited by this include tin, lead and copper.
- 6Sedimentary processes- Alluvial depositsPhysical process. Deposition by moving water of wind. Order of deposition depends on the density of solid. Some examples include gold, diamond and clay.
- 7Sedimentary - chemical depositsEvaporites: crystallisation as water evaporates. Minerals are washed into the sea but as water evaporates the minerals crystallise. Leaves a layer of solid minerals. Coastal lagoons can see frequent evaporation and crystallisation as the lagoon floods and ten gets cut off. Example is halite (Sodium Chloride)
- 8Sedimentary - chemicalManganese nodules - Crystallisation of deep ocean floor. Produced by chemical precipitation on the sea bed. Areas with a high concentration of manganese nodules are in very deep water.
- 9Sedimentary - biologicalLiving organisms concentrate chemical compounds such as wood, bones, coral, and shells. Also limestone and chalk.
- 10Metamorphic processesIntense heat and pressure form these rocks. Slate from mudstones. Marble from limestone and Gneiss from Granite.
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- A level Environmental Studies Flashcards on Geological processes, created by Mollie Munday on 02/02/2019.
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- Mollie Munday
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