Law of conservation of matter
the law that states that matter can neither be created nor destroyed but can only change forms.
rock
The solid material in the earth's crust that is a natural combination of minerals or other materials.
Petrology
the study of rocks, their classification and their history.
3 main groups of rocks
sedimentary, metaphorphic,& igneous
igneous rock
A type of rock that forms from the cooling of molten rock at or below the surface.
sedimentary rock
A type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together.
metamorphic rock
A type of rock that forms from an existing rock that is changed by heat, pressure, or chemical reaction.
texture
The look and feel of a rock's surface, determined by size, shape, and pattern of a rock's grain.
Rock texture is described by 3 characteristics
pattern, shape, and grain size
grains
The particles of mineral or other rocks that give a rock its texture.
Course-grained
igneous rocks that have large visible grains and are usually intrusive.
Fine-grained
igneous rocks that have small grains that require a magnifying class to be seen and are usually extrusive.
intrusive rock
Igneous rock that forms when magma hardens beneath Earth's surface.
extrusive rock
igneous rock that froms from lava on Earth surface.
What characteristics classify igneous rocks?
origin, texture, & mineral composition
granite
A usually light-colored igneous rock with large crystals that is found in continental crust.
basalt
A dark, dense, igneous rock with a fine texture, found in oceanic crust.
Obsidian
an igneous rock described as black volcanic glass
sediment
Small, solid pieces of material that come from rocks or organisms.
order of formation of sedimentary rock
1. erosion 2. deposition 3. compaction 4. cementation
erosion
The destructive process in which water or wind loosens and carries away fragments of rock.
deposition
The process by which sediment settles out of the water or wind that is carrying it.
compaction
The process by which sediments are pressed together under their own weight.
cementation
The process by which dissolved minerals crystallize and glue particles of sediment together into one mass.
3 major types of sedimentary rock
clastic, organic, chemical
clastic rock
Sedimentary rock that forms when rock fragments are squeezed together under high pressure.
4 examples of clastic rock
breccia shale, sandstone, conglomerate, siltstone
organic rock
Sedimentary rock that forms from remains of organisms deposited in thick layers.
2 types of sedimentary rock that forms from livings
Coal and Limestone
chemical rock
Sedimentary rock that forms when minerals crystallize from a solution.
Evaporation
process causes deposits of rock salt (halites) to form
Under what conditions do metamorphic rocks form?
Heat and pressure deep beneath Earth's surface can change any rock into metamorphic rock
How do geologists classify metamorphic rocks?
Geologists classify the metamorphic rocks by the arrangements of the grains that make up the rocks. >foliated,and nonfoliated
foliated
Term used to describe metamorphic rocks that have grains arranged in parallel layers or bands.
Metamorphic rocks that have their grains arranged in parallel layers or bands are said to be ____________.
Foliated Rocks
Some foliated rocks are
slate (most common), schist and gneiss
they split into layers
nonfoliated rocks
Examples are marbel and quartzite, they do not split into layers.
The Rock Cycle
the processes by which, over many years, Earth's materials form and change back and forth among igneous rocks, sedimentary rocks, and metamorphic rocks