i actually have another question too!
- in order for an organism to be used as an index fossil, the organism must have been geographically widespread, what must it have?
a. lived on land b. lived in shallow water c. been preserved by volcanic ash or d. excisted for a geologically short time.
dont make a big fuss about typos.
2007-03-05 10:46:40 · 6 answers · asked by maRijUiCe 1 in Science & Mathematics ➔ Earth Sciences & Geology
Probably the best known is Uranium radioactive dating due to the half life (U-235) has a half live of 713 million years. Carbon dating is not effective for non carbon based and in addition, carbon half lives are shortermaking it effective to only 60,000 years.
An index fossil meets 2 criteria: wide range of where it lived and lived only for a geologically short time. Certain species of trilobites are good index fossils, as are eurypterids
2007-03-05 11:05:51 · answer #1 · answered by ? 6 · 1⤊ 0⤋
Carbon
2007-03-05 10:55:21 · answer #2 · answered by Jeancommunicates 7 · 0⤊ 0⤋
I have no idea about the second question but I konw the answer to the first one (in the title) is carbon because it's called radiocarbon dating
2007-03-05 10:50:39 · answer #3 · answered by MLBfreek35 5 · 0⤊ 0⤋
carbon 13 and d
2007-03-05 10:56:11 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Numerous:
* argon-argon (Ar-Ar)
* fission track dating
* helium (He-He)
* iodine-xenon (I-Xe)
* lanthanum-barium (La-Ba)
* lead-lead (Pb-Pb)
* lutetium-hafnium (Lu-Hf)
* neon-neon (Ne-Ne)
* optically stimulated luminescence dating
* potassium-argon (K-Ar)
* radiocarbon dating
* rhenium-osmium (Re-Os)
* rubidium-strontium (Rb-Sr)
* samarium-neodymium (Sm-Nd)
* uranium-lead (U-Pb)
* uranium-lead-helium (U-Pb-He)
* uranium-thorium (U-Th)
* uranium-uranium (U-U)
d. excisted for a geologically short time
(otherwise, it doesn't tell you about a time frame)
2007-03-05 10:53:13 · answer #5 · answered by novangelis 7 · 1⤊ 0⤋
mostly uranium
2007-03-05 10:55:42 · answer #6 · answered by hey its me 2 · 0⤊ 0⤋