2.3 Rocks, Earth and space

vesicular

a rock with many little holes called vesiculas (has a sponge like texture)

mafic

contains small amounts of silica mineral and high amounts of iron and magnesium

felsic

contains high amounts of silica mineral and low amounts of iron and magnesium

intrusive

when a rock cools underground, broad coarse texture

extrusive

when a rock cools above ground, fine texture

clastic sedimentary

pieces of preexisting rock based on size and shape

organic sedimentary

remains of plants, shells, and other living things when deposited and then buried

chemical sedimentary

substances that are originally dissolved in water from rock when water evaporates

foliated

metamorphic rocks that break well along a flat or slightly wavy parallel plane

non-foliated

forms if pressure is the same from all directions or if the minerals it’s made from doesn’t form crystals

igneous

magma rises above earth’s surface and becomes lava, then cools and solidifies as a new rock

metamorphic

existing sedimentary or igneous rock that is exposed to extreme heat and/or pressure

sedimentary

forms when rock particles are transported by water, wind, or gravity to accumulate into layers of sediment

sill

a layer of magma that has cooled and has sandwiched between rock layers

dike

similar to a sill, but cuts across the layers that it intrudes rather than between them

lithification

process that transforms sediments into solid rocks

parent rock

the original rock from which the younger rock is formed

what are the three main igneous textures we talked about in class?

mafic, felsic, intermediate

what is present in an igneous rock to make it mafic?

small amounts of silica minerals

high amounts of iron and magnesium

what is present in an igneous rock to make of felsic?

high amounts of silica minerals

low amounts of iron and magnesium

what causes regional metamorphism?

due to change in temp and pressure over a large area, generally as a result of tectonic forces

what are the three largest igneous intrusions that we talked about from largest to smallest?

batholith

stock

laccolith

what are the characteristics of intrusive rocks?

broad, coarse-grained texture

what are the characteristics of extrusive rocks?

fine grain texture, can be glass like

how do igneous rock form?

form when magma cools and solidifies

how do sedimentary rocks form?

when rock particles are transported by water, wind, or gravity to accumulate into layers of sediment

how do metamorphic rocks form?

from existing sedimentary or igneous rock that is exposed to extreme heat and/or pressure

what causes contact metamorphism?

caused by the intrusion of hot magma into surrounding rocks

order the sediment sizes we talked about in class from largest to smallest:

cobble/pebbles

breccia

sand

clay