Lab exercise dating rock strata
lab exercise dating rock strata
There are two types of age lab exercise dating rock strata. It is estimated to require four hours of class time, including approximately one hour total of occasional instruction and explanation from the teacher and two hours of group team and individual activities by the students, plus one hour of discussion among students within the working groups. This represents the parent isotope. A key activity in the interpretation of rock strata is dating the layers; that is, determining their ages. Sign up to view the full version. Share this link with a friend: Your username must be at least 5 characters. Sign up to access the rest of the document. Locally, physical characteristics of rocks can be compared and correlated. I am currently a:
There are two types of age determinations. Geologists in the late 18th and early 19th century studied rock layers and the fossils in them to determine relative age. William Smith was one of the most important scientists from this time who helped to develop knowledge of the succession of different fossils by studying their distribution through the sequence of sedimentary rocks in southern England.
It wasn't until well into the 20th century that enough information had accumulated about the rate of radioactive decay that the age of rocks and fossils in number of years could be determined through radiometric age dating. This activity on determining age of rocks and fossils is intended for 8th dating hairstyle games 9th grade students. It is estimated to require four lab exercise dating rock strata of class time, including approximately one hour total of occasional instruction and explanation from the teacher and two hours of group team and individual activities by the students, plus one hour of discussion among students within the working groups.
Explore this link for additional information on the topics covered in this lesson: MCKINNEY THE AGE of fossils intrigues almost everyone. Students not only lab exercise dating rock strata to know how old a fossil is, but they want to know how that age was determined. Some very straightforward principles are used to determine the age of fossils. Students should lab exercise dating rock strata able to understand the principles and have that as a background so that age determinations by paleontologists and geologists don't seem like black magic.
This activity consists of several parts. Objectives of this activity are: Return to top MATERIALS REQUIRED FOR EACH GROUP 1 Block diagram Figure 1. A single watch or clock for the entire class will do. Return to top PART 1: After students have decided how to establish the relative age of each rock unit, they should list them under the block, from most recent at the top of the list to oldest at the bottom. The teacher should tell the students that there are two basic principles used by geologists to determine the sequence of ages of rocks.
Younger sedimentary rocks are deposited on top of older sedimentary rocks. Principle of cross-cutting relations: Any geologic feature is younger than anything else that it cuts across. For example, U is an unstable isotope of uranium that has 92 protons and neutrons in the nucl eus of each atom. Through a series of changes within the nucleus, it emits several particles, ending up with 82 protons and neutrons.
This is a stable condition, and there are no more changes in the atomic nucleus. A nucleus with that number of protons is called lead chemical symbol Pb. The protons 82 and neutrons total This particular form isotope of lead is called Pb U is the parent isotope of Pb, which is the daughter isotope. Many rocks contain small amounts of unstable isotopes and the daughter isotopes into which they decay.
Where the amounts of parent and daughter isotopes can be accurately measured, the ratio can be used to determine how old the rock is, as shown in the following activities. That chance of decay is very small, but it is always present and it never changes. In other words, the nuclei do not "wear out" or get "tired". If the nucleus has not yet decayed, there is always that same, slight chance that it will change in the near future. Atomic nuclei are held together by an attraction between the large nuclear particles protons and neutrons that is known as the "strong nuclear force", which must exceed the electrostatic repulsion between the protons within the nucleus.
In general, with the exception of the single proton that constitutes the nucleus of the most abundant isotope of hydrogen, the number of neutrons must at least equal the number of protons in an atomic nucleus, because lab exercise dating rock strata repulsion prohibits denser packing of protons. But if there are too many neutrons, the nucleus is potentially unstable and decay may be triggered. This happens at any time when addition of the fleeting "weak nuclear force" to the ever-present electrostatic repulsion exceeds the binding energy required to hold the nucleus together.
Very careful measurements in laboratories, made on VERY LARGE numbers of U atoms, have shown that each of the atoms has a In other words, during million years, half the U atoms that existed at the beginning of that time will decay to Pb This is known as the half life of U- Lab exercise dating rock strata elements have some isotopes that are unstable, essentially because they have too many neutrons to be balanced by the number of protons in the nucleus.
Each of these unstable isotopes has its own characteristic half life. Some half lives are several billion years long, and others are as short as a ten-thousandth of a second. On a piece of notebook paper, each piece should be placed with the printed M facing down. This represents the parent isotope. The candy should be poured into a container large enough for them to bounce around freely, it should be shaken thoroughly, then poured back onto the paper so that it is spread out instead of making a pile.
Geologists in the late 18th and early 19th century studied rock layers and the fossils in 5) To use radiometric dating and the principles of determining relative age to show how Very careful measurements in laboratories, made on VERY LARGE numbers of U The next part of this exercise shows how this is done. Students will understand the concept of relative age dating, the Principle of Original of demonstration such as layers of clay) can be helpful, especially with exercise. As soon as the students see the edible rocks (i.e. Snickers bars), they are. Topic: Relative age dating of geologic cross sections Content Objective: This exercise will introduce your students to the concept of relative . Figure B. Oldest rocks: A, followed by B, C and D. All four sedimentary layers were folded into a. All of the rock layers exposed at the surface in Arkansas have been named and formations in Arkansas are mentioned in this lab exercise and other exercises.