Download presentation

Presentation is loading. Please wait.

Published byYadiel Dopkins Modified over 4 years ago

1
Carbon Dating I While alive, every being has a constant ratio of C(14) to C(12) –Cause: absorption from the atmosphere cosmic rays transform N(14) to C(14) –N(14) + N --> C(14) + P the ratio of C(14) to other forms of carbon remains constant during the lifetime of the object studied. N n C

2
www.c14dating.com Carbon Dating II When Dead, no more absorption of carbon takes place –the C(14) begins its decay to N(14) C(14) --> N(14)+ e hence the ratios of C(12) to C(14) change this change can be measured by the rate of nuclear activity C(14) has a half-life of only 5730 years, so only very young things can be measured (~50000 yrs.)

3
Carbon Dating III –Inaccuracies: the sun is not constant in its output many species do not attain carbon from the atmosphere, etc. –How to counteract the inaccuracies tree rings, ice core samples fine-tune the model

4
http://archserve.id.ucsb.edu/Anth3/C ourseware Potassium-Argon Dating Argon gas in volcanic samples is measured –Molten rock releases all argon initially present –Argon is then formed by the decay of potassium K(40) + e ---> Ar(40) + e

5
www.c14dating.com Potassium-Argon Dating II –Only very small amounts are found, which is the reason the K is not measured directly –The argon is measured by mass spectometry the ratio of potassium to argon gives a date –Objects as old as 4.5 billion years have been measured

Similar presentations

OK

Radioactive Dating D.3.1 Outline the method for dating rocks and fossils using radioisotopes, with reference to 14C and 40K.

Radioactive Dating D.3.1 Outline the method for dating rocks and fossils using radioisotopes, with reference to 14C and 40K.

© 2018 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google