Why is radiometric dating not accurate for sedimentary rocks
Sedimentary rocks cannot be dated directly using radiometric dating, which is the conditions necessary to achieve accurate results through radiometric dating. Geologists use radiometric dating to estimate how long ago rocks formed, and to infer the Fossils are generally found in sedimentary rock — not igneous rock. Sedimentary rocks (made from mud, sand, gravel or fossil shells) and volcanic lava and it is most important way of working out the order of rocks in time. To get an age in years, we use radiometric dating of the rocks. Not every rock can be dated this way, but volcanic ash deposits are among those that can be dated.
Why is it difficult to date sedimentary rocks using radiometric dating techniques? Because the elements used for dating need to be re-set by volcanism. Related questions What is the principle of Uniformitarianism and how is it important to the relative dating of rocks? What is the age of inclusions found in a rock relative to the rock in which they are found? What is the principle of cross-cutting relations and why is it important for relative dating?
What forces can disturb relative dating? What is the law of superposition and how can it be used to relatively date rocks? Tracing of rocks and fossils from one place to another is called correlation. We cannot be sure if the rock layers with the same fossils are identical in age. We can say that the rocks formed during the time in which the fossil species lived.
If a fossil has been dated radiometrically in one place, correlation allows use to work out the age in other places. In the above example, we know that the fossil in Nevada is slightly older than the ash layer dated to million years old. We can say that same species in Oklahoma must also be about million years old, even though there is no volcanic ash layer present at this site. Norman, OK Based on the analysis of these samples, scientists estimate that the Earth itself is about 4.
In addition, the oldest known moon rocks are 4. Since the moon and the Earth probably formed at the same time, this supports the current idea of the Earth's age. You can learn more about fossils, dinosaurs, radiometric dating and related topics by reading through the links below.
Radiometric dating isn't the only method of determining the age of rocks. Other techniques include analyzing amino acids and measuring changes in an object's magnetic field.
Scientists have also made improvements to the standard radiometric measurements. For example, by using a laser, researchers can measure parent and daughter atoms in extremely small amounts of matter, making it possible to determine the age of very small samples [source: Saber-tooth Kittens Were Big-boned.
An eagle flies over the Grand Canyon in Arizona, April 5,