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fossils
Question | Answer |
---|---|
the preserved remains/traces of living things | fossil |
the type of rock that is made of hardened sediment | sedimentary rock |
a hallow area in sediment in the shape of an organism or part of an organism. | mold |
a solid copy of the shape of an organism | cast |
fossils in which minerals replace all or part of an organism | petrified fossil |
an extremely thin coating of carbon on rock | carbon film |
provide evidence of the activities of ancient organisms | trace fossils |
scientists who study fossils | paleontologists |
a well tested concept that explains a wide range of observations | scientific theory |
a type of organism that no longer exists and will never again live on earth | extinct |
a rock's age compared to the ages of other rocks | relative age |
a rock's number of years since the rock formed | absolute age |
used to determine that relative ages of sedimentary rock layers | law of superposition |
lava that hardens on the surface | extrusion |
an igneous rock layer formed when magma hardens beneath earth's surface | intrusion |
the surface where new rock layers meet a much older rock surface beneath them | unconformity |
a fossil must be widely distributed and represent a type of organism that existed only briefly | index fossil |
a break in earth's crust | fault |
all the matter you see, including rocks, is made of these tiny particles | atom |
when all the atoms in a particular type of matter are the same, the matter is this | element |
over time, elements break down, or decay, by releasing particles and energy in this process | radioactive decay |
of a radioactive element is the time it takes for half of the radioactive atoms to decay | half life |