Know these words Flashcards
relative dating
Relative dating is the process by which we compare other rocks around a rock to find an estimate of the age of the rock we are trying to find the age for, relative dating is the process of finding relative age.
The process of relative dating to find relative age of a rock would be igneous intrusions, index fossils, the law of superposition, faults, and the most important comparing other rocks and their layers around them to get a relative age of a rock .
index fossil
An index fossil is a fossil of an organism that was widely disturbed and existed for a geologically short period of time.
Index fossils help geologists to match and date rock layers, even if those layers are far apart or in different locations. They can help find the relative age of whatever rock layer it is in. Geologists can say that layers with the same index fossils are the same age.
fossil
The preserved remains or traces of an organism that lived in the past.
They often occur in sedimentary rock. Fossils preserved in rock can give us physical evidence of how old a rock may be, it also can provide us with the history of life on earth and how earth has changed over time.
superposition
Superposition states in undisturbed horizontal sedimentary rock layers, the oldest layer at the bottom and the highest layer / youngest at the top. The higher you go the younger it is, the deeper you go the older it is.
The law of superposition can help determine the relative age of sedimentary rock layers.
absolute dating
absolute dating is the process of finding the absolute age of a rock. Absolute dating process will consist of using radioactive dating, and half-life to figure out the exact age of a rock.
Geologists use radioactive dating to find the absolute age of rocks. Radioactive dating is the process of radioactive decay, radioactive decay is finding out the amount of radioactive decay is in a rock, next they compare the stable element into which the radioactive element decays. They will use this and a half-life to find the absolute age of a rock.
half-life
Each radioactive element decays at its own constant rate, represented by its half-life. The half-life of a radioactive element measures the time it takes for half of the radioactive atoms to decay into a different element.
Scientists use half-life to calculate the age of the rock in which a radioactive element is found.
seismic waves
Seismic waves specific meaning is Vibrations that travel through Earth carrying the energy released during an earthquake.
Seismic waves can differ from P-Waves and S-waves. P-waves stand for Primarily waves which can pass through all of the layers in Earth. (They pass through liquids and solids). S-waves are Secondary waves, they can only travel through the crust, mantle (They only travel through solids).
