Relative ages are determined by the chronologic order of a sequence of events. Explain the most important methods of establishing relative ages:
1. superposition, origianal horizontality, and lateral continuity,
3. crosscutting relations- The rock that is cutting through the layers is newer than the rock that it is cutting through.
4. Inclusions- The rock that is included in another rock is older than the rock it is included in.
5. Unconformities-
What is Half-Life? Half lie is the amount of time it takes for an element or substance to decompose into half of what was there to begin with.
How can you demonstrate this process to your kids? You could use skittles or m&m’s and you put them on a grid with 100 squares. You put them in a cup and shake them up, and count the ones that are face up. You then take the face-up candies and shake those up in a cup and count those face up candies. You continue that until you get to 0 candies that are face up.
1. superposition, origianal horizontality, and lateral continuity,
- superposition- younger layers overlie older layers. The oldest layer of rock is on the bottom.
- Lateral Continuity-: layers of sediment now truncated must have been deposited as laterally continuous layers. When rocks are first laid down they are one piece of rock. They can then be cut or broken apart by a fault and so on.
- Original horizontality: layers now inclined must have been deposited as nearly horizontal layers. When layers of rock are first laid down, they were flat (horizontal).
3. crosscutting relations- The rock that is cutting through the layers is newer than the rock that it is cutting through.
4. Inclusions- The rock that is included in another rock is older than the rock it is included in.
5. Unconformities-
- Disconformity-rock layers are parallel
- Nonconformity-younger sedimentary rock is separated from an igneous or metamorphic rock.
- angular unconformity-the rock layer that separates the layer of rocks above the angled, older rocks underneath.
What is Half-Life? Half lie is the amount of time it takes for an element or substance to decompose into half of what was there to begin with.
How can you demonstrate this process to your kids? You could use skittles or m&m’s and you put them on a grid with 100 squares. You put them in a cup and shake them up, and count the ones that are face up. You then take the face-up candies and shake those up in a cup and count those face up candies. You continue that until you get to 0 candies that are face up.