rocks quiz Flashcards
Extrusive
volcanic
lava solidifies quickly at or near the surface → rocks can be non crystalline/glassy or have crystals <1mm
Intrusive
plutonic
magma solidifies slowly deep underground → rocks
have larger crystals >1mm
Felsic
light in color, low in density (left side of the chart)
Mafic
dark in color, high in density (right side of the chart)
monomineralic
Rocks made of one mineral
polymineralic
Rocks made of many minerals
Formation processes for clastic sedimentary rocks
weathering & erosion; deposition & burial; compaction and/or cementation (in rock cycle diagram on page 6)
Sedimentary rock can contain_____
fossils
Three types
Clastic, Crystalline, Bioclastic
Clastic
made of fragments (pieces of other rocks/sediments) cemented together; classified by grain size
Crystalline
crystals from chemical precipitates or evaporites; monomineralic
Bioclastic
precipitates of biologic origin or cemented shell fragments or compacted plant remains
Metamorphic formed by ______
heat and pressure
Made from__________
other rocks
Two types of Metamorphism
Regional and Contact
Regional
Rock is put under intense pressure and heat over large areas
Contact
Rock is heated by lava or magma
Two categories
Foliated and Non-Foliated
Foliated
show mineral alignment and banding(only gneiss) - layering
Non-Foliated
can be monomineralic or crystalline
Vesicular
formed by expansion of a bubble of gas or steam during solidification of the rock
All the steps for clastic rocks
weathering and erosion- larger rock fragments being broken up and then moved
sediments- outcome of weathering and erosion
deposition- sediments being dropped off
burial- sediments being buried after drop off
compression- the more layer you get, the greater the pressure under the surface
compaction- the pressure causes compaction (sediments getting nice and close together)
cementation- after compaction, sediments get glued through a natural cement
recrystallization
crystals in rocks organizing them selves due to the heat and pressure based off density
