geologic dating exam 4
Log in Sign up. How can we help? What is your email? Upgrade to remove ads. The process of determining whether an object or event is older or younger than other objects or events. Relative age does not. Indicate the rock's age. States that geologic processes in the past can be explained by current geologic processes. The principle that states that younger rocks lie above older rocks if the layers have not been disturbed.
If sedimentary rock layers are not horizontal then what has happened? Something has disturbed them after they were formed. What can disturb rock layers so much that they place older layers on top of younger layers? Forces in the earth, such as tilting, folding, faults, and intrusions. When the earth's forces move rock layers up or down unevenly, so that the layers are slanted.
The bending of rocks when rock layers are squeezed sideways. A break or crack cs go matchmaking console commands the Earth's crust along which rocks shift position. A mass of igneous rock that forms when magma is injected rock and then cools. A gap in the geologic rock record that forms when rock layers are eroded or when sediment is not deposited for a long time. What are the processes that can disturb sedimentary rock layers?
Nonconformity, diconformity, angular unconformity. Define absolute dating and explain how it is different from relative dating that a fault or a body of rock, such as an intrusion, must be younger than any feature or layer or rock that the fault or rock body cuts through. How can Scientists establish the relative ages of rocks? By using fossils in undisturbed sequence of rocks. A standard method used by earth scientists to obtain the relative ages of rock layers. An ordered arrangement of rock layers that is based on the relative ages of the rocks, with the oldest rocks at the bottom.
If two layers match, then they are likely to be what at the same time? Determining the age of an event or object in years. How do scientists determine the absolute age of rocks? Atoms of the same element that have a different number of neutrons. The breakdown of a radioactive isotope into a stable isotope of the same element or of another element. The average time needed for half of a sample of a radioactive isotope to undergo radioactive decay to form daughter isotopes.
What is Half-life measured in? Some radioactive isotopes in mineral Crystals can act as what? Finding the absolute age of a sample by determining the relative percentages of a radioactive parent isotope and stable daughter isotope. What are the best rocks for radiometric dating? Why are igneous rocks best for radiometric dating?
When they form, minerals often contain only a parent isotope define absolute dating and explain how it is different from relative dating none of the daughter isotopes. It makes the percentages easier to interpret and makes dating more accurate. Can Radiometric dating techniques be used to date sedimentary rock? Scientists have established a way of determining an age range for rock layers using certain fossils. How do you determine Index fossils? Must be found in a large rocky area, must have features that make it different from other fossils, the organism from which the fossil was formed must have lived for a short amount of geologic time, there must be a large number of fossils in the rock layers.
Index fossils act as what? Markers for the time that the organisms were on Earth. They are usually for short periods of times.