Table of Contents
- 1 Which law states disruptions in any rock sequence occurs after the youngest established event in the undisturbed sequence?
- 2 What do scientists know about an undisturbed sequence of rocks based on superposition?
- 3 How are sedimentary rock layers disturbed?
- 4 What does the principle of cross-cutting relationships state?
- 5 What type of rocks usually undergo cross cutting on rock layers?
- 6 How are undisturbed rock sequence arranged?
Which law states disruptions in any rock sequence occurs after the youngest established event in the undisturbed sequence?
The law of superposition states that a sedimentary rock layer in a tectonically undisturbed sequence is younger than the one beneath it and older than the one above it.
What do scientists know about an undisturbed sequence of rocks based on superposition?
Superposition is the principle that says younger rocks lie above older rocks in an undisturbed sequence. Scientists use the fossils of animals to help determine relative age. Rock layers represent “historical events,” so a rock layer is like a page in the book of Earth’s geologic history.
How do geologists figure out rock layer puzzles?
Scientists often determine the correct sequence of sedimentary rock layers using the fossils found within them. They compare the fossils to fi gure out if two layers are from the same geologic time period, or if one layer is older than the other.
What is one thing that tells a geologist that rock layers have been disturbed?
Flat, horizontal layers of sediment should form flat, horizontal layers of rock. If rock layers are not horizontal, then some force must have disturbed them after they were formed. Folding and tilting are two ways that rock layers can be disturbed.
How are sedimentary rock layers disturbed?
Folding and tilting are two events that disturb rock layers. Folding is the bending of rock layers that results from stress. Tilting happens when Earth’s forces move rock layers so that they are slanted.
What does the principle of cross-cutting relationships state?
Cross-cutting relationships is a principle of geology that states that the geologic feature which cuts another is the younger of the two features. It is a relative dating technique in geology.
How does the law of crosscutting explain the age of a fault?
Q. How does the law of crosscutting explain the age of a fault? The fault is younger than the rocks above it. The fault is younger than the rocks it cuts through.
What does the idea of superposition say about rock layers that have not been disturbed?
The law of superposition is the principle that states that younger rocks lie above older rocks if the layers have not been disturbed.
What type of rocks usually undergo cross cutting on rock layers?
A geologic cross section: Sedimentary rocks (A-C), igneous intrusion (D), fault (E). The principle of cross-cutting relationships states that a fault or intrusion is younger than the rocks that it cuts through. The fault cuts through all three sedimentary rock layers (A, B, and C) and also the intrusion (D).
How are undisturbed rock sequence arranged?
The principle of superposition states that in undisturbed rock sequences, younger layers lie above older layers. Folding and tilting are two events that disturb rock layers.
What is a break in the geologic record created when rock layers?
Fossil Vocabulary
| A | B |
|---|---|
| Uncomformity | A break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time.Also called a break in the geologic record. |
| Intrusion | An instrusion is molten rock from Earth’s interior that squeezes into existing rocks and cools |