Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


Isotope Rock Dating

This is a short, simplistic prezi on how the concept of rock dating and its many mysteries work. NOTE: This is my first prezi. Forgive me if this turns out like crap...

Colten Smith

on 17 May 2010

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Isotope Rock Dating

Isotope Rock Dating How do geologists know how old a rock is? Geologists usually can determine the age of a rock by studying the formation and/or condition the rock is found in. This is called the Geological Time Scale. The Geological Time Scale The Geolgical Time Scale is a type of scientific calendar that tells the time and age of a rock. There are two ways in order to fundementally tell time from this scale. One way is Relative Dating, and the another is Absolute Dating. First, we will discuss Relative Dating... Relative Dating One of the most familiar and basic aspects of the concept of Relative Dating is a law called Superposition. This law states that each layer of sedimentary rocks is older than the ones above it. An example can be seen below... Fanual Succession The law of Fanual Sucession states that different fossils of various animals and plants can be identified through these rock formations. Through this law, the rocks can be "dated" corresponding to their content. Some fossils are called index fossils, which are certain types of fossils that are notorious for their rapid evolving rate. Here is an example of one... Notice how the fossil is embedded in the rock itself, signifying a clear indication of an index fossil. Cross-cutting Relationships also help determine a rock's age with the help of igneous rock that worms its way into creating a fissure in the layers of the rock. This is called an intrusion. It is proven that these faults, fissures, intrusions....whatever you want to call them are younger than any of the said rock layers they intruder through. Next, we will move on to Absolute Dating... Absolute Dating is the term referred to as the aging (and determining that age) of a previously known site or artifact. One of the most important principles of Absolute Dating is that the word, "absolute" resembles an implication of precision, which is rarely possible in terms of archaeology. Radiometric Dating, based on Absolute Dating principles, is a way of finding a rate of decay in radioactive isotopes. The intitial and probably most essential ways of measuring an isotope is by their half-life. A common term used in acrhaeology, the Half-Life (not the video game) is used to measure the time it takes for a substance's/isotope's rate of decay to decrease by half. For most materials, a longer half-life means better accuracy and more detailed reading of the isotope or material. Another important aspect of Absolute Dating is that of Radioactive Decay.
This means that a "parent" isotope changes into a "daughter" isotope. This is a further, more legit defintion of half-life, saying that this is the time frame it takes for a parent isotope to decay into a daughter isotope, which is much stabler. This is an example of a decaying sulfur parent isotope. It is rapidly evovling into a more stable substance: A daughter isotope. The following is a chart that says all half-lives for a diverse combination of isotopes... The defintion of a daughter isotope is: An isotope produced
by the decay of another isotope, such as a parent isotope. One of the most common is uranium-238, which a half-life of 4.5 billion years! This is how isotopes like uranium decay by using the
principle of the Alpha Particle. These "Alpha Particles" carry a crap-load of energy, way more than a
regular particle. These particles bump into other atoms and molecules. This can be potentially damaging because they don't travel far in living tissue. This reaction is called the Compton Effect...
Full transcript