Classifying Rocks
Geologists classify rocks into 3 major groups
igneous, sedimentary, and metamorphic
Igneous rock that formed from magma and cooled very slowly UNDERNEATH the earth's surface is called ________.
intrusive rock
These small pieces or particles make up sedimentary rock. They can be other rocks or plant and animal organisms
sediments
This is how metamorphic rocks are created.
extreme heat and pressure
Magma cools and crystallizes in the cycle forming _______ rock
igneous rock
The type of rock that forms from magma or lava cooling
igneous rock
This type of rock is formed from lava ON the earth's surface.
extrusive rock
This type of rock can be found on the local streets during the winter.
rock salt
These types of rocks can become metamorphic rocks
igneous, sedimentary and other metamorphic rocks
Igneous rock transform to sediment by processes called ___________ & ____________
weathering and erosion
The small units that make up a rock and its texture are called __________.
grains
This action causes holes to form in extrinsic rock when it is formed.
gases being released.
Sedimentary rocks can form from deposits made in ___________
streams or oceans
The process in which magma comes in contact with existing rock
contact metamorphism
The layers of sediment become pressed together over time
compaction
Geologists study the ________ & ________ of a rock in order to identify it.
texture and composition
This type of igneous rock is black with a glassy texture. There is a picture in your textbook.
obsidian
This type of rock is formed by organisms. Coal was the example we gave in class.
biochemical rock
The texture of a metamorphic rock arranged in parallel layers is called
foliated
The tectonic process that forces rocks onto the earth's surface is called __________
uplift
Igneous rock cools very quickly.When it forms the rock could be described as _________.
smooth or shiny or no visible crystals
This igneous rock can float in water, it also has holes due to the release of gases
pumice
This type of sedimentary rock is made up of broken pieces of rock and minerals
clastic rock
Limestone becomes ___________ under extreme temperature or pressure.
marble
The processes by which sediments become sedimentary rocks
Deposition, compaction or cementation