Chapter 8 science study guide Flashcards
the study of structure of planet Earth and the forces that make and shape the Earth
geology
occurs when running water, ice, or windbreak down rocks and carry the pieces away
erosion
states that the geologic processes that operate today also operated in the past
uniformitarianism
rocks that form when molten material form beneath Earth’s surface cools and hardens
igneous rock
a rock made of sediments that have been deposited and then pressed together to form a solid rock
sedimentary rock
a rock that forms when an existing rock is changed by heat, pressure, or chemical reactions
metamorphic rock
a series of processes on and beneath the Earth’s surface that slowly change rocks from one kind to another
rock cycle
molten material beneath Earth’s surface
magma
magma that flows on to Earth’s surface
lava
a rock’s age compared to the ages of other rocks
relative age
the number of years since a rock has been formed
absolute age
states that in horizontal sedimentary rock layers the oldest layer is at the bottom. Each higher layer is younger than the layers below it
law of superposition
lava that hardens on the surface
extrusion
when the magma cools and hardens in to a mass of igneous rock
intrusion
a break in Earth’s crust
fault
the surface where new rock layers meet a much older rock surface beneath them
uncomformity
a piece of rock that is contained in another rock
inclusion
a fossil that tells the relative ages of the rock layer in which they occur
index fossil
all the matter you see, including rocks, is made of tiny particles called _____
atom
When all the atoms in a particular type of matter are the same, the matter is an _________
element
when the atoms of one element break down to form atoms of another element
radioactive decay
The time it takes for half of the radioactive atoms to decay
half-life
the 12 pieces that the outer layer of the Earth is made of
plates
states that Earth’s landmasses have changed position over time because they are part of plates that are slowly moving
the theory of plate tectonics
the very slow movement of continents
continental drift
a record of the life forms and geologic events in Earth’s history
geologic time scale
the three long units between Precambrian time and the present.
Eras
Eras subdivion
periods
animals without backbones
invertebrates
animals with backbones
vertebrates
an animal that lives part of its life on land and part of its life in the water
amphibian
animals that have scaly skin and lay eggs with tough, leathery shells
reptiles
a time in which many types of living things become extinct at the same time
mass extinction
a warm-blooded vertebrate that feeds its young milk
mammal
