Relative Dating
All About Rocks
Disturbed Rock Layers
Rock Puzzles
Assumptions Geologists Make
100
What is relative dating?
Weather an object or event is older or younger than other objects or events.
100
What is a disconformity?
Part of a sequence of parallel rock layers is missing.
100
What is a fault?
Break in earths crust along which blocks of the crust slide relative to one another
100
Can you lable this rock puzzle?
http://www.docbrown.info/page12/gifs/layers8Q.gif
100
What is the 1st assumption?
Scientists know that the features that cut across rock layers are younger than the rock they cut across.
200
What is absolute age?
The age in years of a rock or other object (specific)
200
What is a nonconformity?
Sedimentary rock layers lie on top of an eroded surface of nonlayered igneous or metamorphic rock.
200
What is an intursion
Molten rock from Earth's interior squezzes into rocks and cools.
200
What is the disturbance in this picture?http://www.mrsciguy.com/EarthScience/earthsciimages/rd09.gif
Fault
200
What is the 2nd assumption?
Sediment is deposited horizontally. If rock layers are not horizontal something disturbed the layers.
300
What is the principle of superposition?
The principle that older rocks lie on the bottom and younger rocks lie near the top.
300
What is an angular unconformity?
It exists between horizontal rock layers and rock layers that are tilted or folded.
300
What is folding?
Rock layers bend and buckle due to Earth's internal forces.
300
What is this disturbance? http://www.mrsciguy.com/EarthScience/earthsciimages/rd11.gif
intrusion
300
What is the 3rd assumption?
Missing rock layers create gaps in rock layer sequences called unconformities.
400
What is Geologic Column
What is An ideal sequence of rock layers that contains all the known fossils and rock formations on earth arranged from oldest to youngest
400
What is the geologic column?
An ideal sequence of rock layers that contains all the know fossils and rock formations on earth arranged oldest to youngest.
400
What is tilting of a rock?
Internal forces in the Earth slant rock layers without folding them.
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