Rocks and weathering Flashcards
What is the rock cycle?
1) Weathering or erosion of rocks
2) Deposition into ocean
3) Burial and compaction (sedimentary rocks)
4) Deformation and metamorphism (metamorphic rock)
5) Melting and crystallisation of magma (igneous rocks)
6) Uplift then weathering and erosion
What are the 2 types of igneous rocks?
Intrusive and extrusive
What happens to the silica content after increases density?
lower silica content (less explosive)
What feature are formed from igneous rocks?
Dikes, sills and columnar jointing
What is magma a mixture of?
gas, melt and crystals (size of crystals affects cooling rate)
What is vesticulation?
formation of gas bubbles
How are metamorphic rocks created?
Modificaition of rocks by heat, pressure, chemical solutions and recrystallisation
What are the different types of metamorphism?
Contact (thermal)
Burial
Regional (plate collision)
Shock (impact)
Seafloor (hydrothermal)
What features do metamorphic rocks create?
planar feature in rocks produced by flattening is foliation
How is sedimentary rock formed?
Burial of sediment, pores eliminated forming consolidated rock
What 2 ways are sedimentary rocks drives by?
Compaction
Cementation
Where can sediment from weathering come from?
Physical weathering - ranging particle size
Chemical - dissolved materials
Biochemical - shells and skeleton of organism
What formation can sediment from when reaching body of water?
Alluvial fan
Are covalent or ionic bonds more prone to weathering?
Ionic
What is oxidation weathering?
Weathering of iron bearing minerals, reacts with O to form iron oxides and go red/brown
