Which of the following are methods of relative aging of rocks? Select the three correct answers.(2 points)
1) radiometric dating
2) original horizontality
3) superposition
4) angular relationships
5) cross-cutting relationships
6) original angularity
The correct answers are:
3) superposition
5) cross-cutting relationships
6) original angularity
The three correct methods of relative aging of rocks are:
1) Superposition: This principle states that in a sequence of sedimentary rock layers, the youngest rock layer is on top while the oldest is on the bottom. It helps determine the relative ages of rocks based on their position in the sequence.
2) Cross-cutting relationships: This principle states that any feature cutting across a rock or body of sediment must be younger than the rock or sediment it cuts across. This method helps determine the relative ages of rocks based on the presence of cross-cutting features like faults or intrusions.
3) Original horizontality: This principle states that sedimentary rocks are usually deposited in horizontal layers. If rocks are tilted or folded, it suggests that they have been deformed after deposition, allowing researchers to estimate their relative ages based on their original horizontal orientation.
To determine the three correct methods of relative aging of rocks, you can analyze each option and identify the ones that fit the criteria.
1) Radiometric dating: This method is not a technique used for relative dating but for absolute dating. It helps determine the actual age of a rock or fossil by measuring the ratio of radioactive isotopes present.
2) Original horizontality: This method is one of the principles used in relative dating. It states that sedimentary rocks are originally deposited in horizontal layers. Any deviation from this horizontal orientation could signify an event that occurred after deposition.
3) Superposition: This principle is another method of relative dating. Superposition states that the rock layers closer to the surface are younger compared to those below. This method relies on the idea that sedimentary rock layers accumulate over time, with the older layers being at the bottom.
4) Angular relationships: Angular relationships refer to the orientation or inclination of rock layers. While this can provide some information about the geological history, it is not a distinct method for relative dating.
5) Cross-cutting relationships: This method is another principle used in relative dating. It states that any feature cutting across a rock layer is younger than the layer itself. This could include faults, intrusions, or erosion surfaces.
6) Original angularity: This option is not a recognized method of relative dating. It seems to refer to the initial angle or inclination at which rock layers were deposited, but it is not a principle or technique used for relative dating.
Therefore, the correct answers for the three methods of relative aging of rocks are:
- Original horizontality
- Superposition
- Cross-cutting relationships