Hi everyone. Just wondering how geo's can determine the age of rocks. Is it to do with carbon dating or some other process?
2006-10-25 13:06:55 · 6 answers · asked by blairyeyes 1 in Science & Mathematics ➔ Earth Sciences & Geology
Carbon-14 dating is one way. Measurements of other isotopes are another way.
Basically, its knowing where you are in the geologic time frame. Being able to figure out what rock type you have, where it came from, and formation it is a part of - are key ingredients to figuring out its age. Fossils also give clues. Coals, for example, formed mainly during the Pennsylvanian period (about 300 to 325 million years ago). We also rely on the law of superposition which very basically means that older rocks are on the bottom and younger rocks are on the top, provided that they are not affected structurally, like being overturned.
Where I live I can see Cambrian rocks in the mountains to the south of me and Devonian rocks in the mountains just north of me. I also know that my house sits on an Ordovician shale.
The key to dating rocks is knowing what you have and where it came from. There is not that much magic involved, just a lot of detective work.
Take some basic geology courses at your local college or university. You will be surprised what you will learn.
2006-10-25 15:33:58 · answer #1 · answered by Tom-PG 4 · 0⤊ 0⤋
Geologists use a Carbon-14 test I think it is and use an equation that basically taking a sample of Carbon and determining from the half life of the Carbon isotope what age the rock is, this test is used on most age determination tests like: artifacts, mummies, etc.
2006-10-25 13:17:40 · answer #2 · answered by anjelfun 4 · 0⤊ 0⤋
Yes, they determine the age of rocks from carbon dating. Geo's measure the radiation for a day (for example) and then see how long it takes for that radiation to half... This is the half life of a rock and form that they can count back to see how old it is...
2006-10-25 13:18:00 · answer #3 · answered by Anonymous · 0⤊ 0⤋
By doing something called relative dating or carbon dating (One of the two)
2006-10-25 14:26:37 · answer #4 · answered by Anonymous · 0⤊ 0⤋
They can do carbon dating, but they sometimes look at the layers of rock and what they know about the earth/weather/other circumstances of the time period.
2006-10-25 13:08:45 · answer #5 · answered by lolfunswirlies 3 · 1⤊ 0⤋
they can use carbon dating. they also can tell just by looking at it. the old ones are more round and smooth. the ones that just formed usally are more jagged
2006-10-25 13:10:26 · answer #6 · answered by Chris C 2 · 0⤊ 0⤋