Teaching about Earth's history is a challenge for all teachers. Time factors of millions and billions of years is difficult even for adults to comprehend.
However, "relative" dating or time can be an easy concept for students to learn. Once they are able to manipulate the cards into the correct sequence, they are asked to do a similar sequencing activity using fossil pictures printed on "rock layer" cards.
Sequencing the rock layers will show students how paleontologists use fossils to give relative dates to rock strata. Once students begin to grasp "relative" dating, they can extend their knowledge of geologic time by exploring radiometric dating and developing a timeline of Earth's history.
These major concepts are part of the Denver Earth Science Project's "Paleontology and Dinosaurs" module written for students in grades Extinction of species is common; most of the species that have lived on the earth no longer exist. The complete "Paleontology and Dinosaurs" module takes approximately four weeks to teach.
The "Who's On First? Scientific measurements such as radiometric dating use the natural radioactivity of certain elements found in rocks to help determine their age. Scientists also use direct evidence from observations of the rock layers themselves to help determine the relative age of rock layers. Specific rock formations are indicative of a particular type of environment existing when the rock was being formed.
For example, most limestones represent marine environments, whereas, sandstones with ripple marks might indicate a shoreline habitat or a riverbed. Return to top The study and comparison of exposed rock layers or strata in various parts of the earth led scientists in the early 19th century to propose that the rock layers could be correlated from place to place.
Locally, physical characteristics of rocks can be compared and correlated. On a larger scale, even between continents, fossil evidence can help in correlating rock layers. The Law of Superposition, which states that in an undisturbed horizontal sequence of rocks, the oldest rock layers will be on the bottom, with successively younger rocks on top of these, helps geologists correlate rock layers around the world.
This also means that fossils found in the lowest levels in a sequence of layered rocks represent the oldest record of life there. By matching partial sequences, the truly oldest layers with fossils can be worked out.
By correlating fossils from various parts of the world, scientists are able to give relative ages to particular strata. This is called relative dating. Relative dating tells scientists if a rock layer is "older" or "younger" than another.
This would also mean that fossils found in the deepest layer of rocks in an area would represent the oldest forms of life in that particular rock formation.
In reading earth history, these layers would be "read" from bottom to top or oldest to most recent. If certain fossils are typically found only in a particular rock unit and are found in many places worldwide, they may be useful as index or guide fossils in determining the age of undated strata.
By using this information from rock formations in various parts of the world and correlating the studies, scientists have been able to establish the geologic time scale. This relative time scale divides the vast amount of earth history into various sections based on geological events sea encroachments, mountain-building, and depositional eventsand notable biological events appearance, relative abundance, or extinction of certain life forms.
Objectives: When you complete this activity, you will be able to: 1 sequence information using items which overlap specific sets; 2 relate sequencing to the Law of Superposition; and 3 show how fossils can be used to give relative dates to rock layers. Materials: two sets of sequence cards in random order set A : nonsense syllables; set B : sketches of fossilspencil, paper Procedure Set A: 1 Spread the cards with the nonsense syllables on the table and determine the correct sequence of the eight cards by comparing letters that are common to individual cards and, therefore, overlap.
The first card in the sequence has "Card 1, Set A" in the lower left-hand corner and represents the bottom of the sequence.Finding Lab Activities Online For relative information on the project as well as instructions on how to use the site: Minerals Online rock and mineral identification earthquake by Jonathan Evenick of the University of Tennessee - provides photographs and descriptions of various rocks and minerals. Mineral identification and properties getting photographs by Richard Harwood of Black Hawk College - students can identify minerals photographs based on mineral property choices.
Earth Science Lab Relative Dating 2 Key
This site has been taken down. Contact us if you know of a suitable sciencecourseware. Absolute mineral fossil by Amethyst Galleries, Inc. Descriptions of each mineral include physical games, sciencecourseware information, absolute uses, and relative formulas as well as pictures. Mineral fossil by Dave Jessey and Don Tarman through Cal State Pomona - students can getting this site as a step-by-step tutorial to identify mineral sample.
Igneous Rocks Igneous rock identification using photographs by Richard Harwood of Black Hawk College - students can identify igneous rock photographs based on rock property choices, lab-checking. Igneous fossil identification by Dave Jessey and Don Tarman through Cal State Pomona - games getting use this site as a step-by-step tutorial to identify igneous rock samples.
Sedimentary Rocks Sedimentary rock identification using photographs by Richard Harwood of Black Hawk College - students getting identify sedimentary earthquake games based on rock property choices, intro-checking.
Metamorphic Rocks Metamorphic rock identification using photographs by Richard Harwood of Black Hawk College - students can identify metamorphic rock photographs based on rock property choices, self-checking.
Metamorphic rock identification by Dave Jessey and Don Tarman through Cal State Pomona - students can use this site as a step-by-step fossil to identify metamorphic rock samples. An interactive map where students can turn on and off features absolute as earthquakes, plate boundaries and names, faults, worksheet, etc. Volcanic materials identification using photographs by Richard Harwood of Black Hawk College - students can identify volcanic material photographs based on sciencecourseware choices, self-checking.
Volcanoes laboratory by Richard Harwood of Black Hawk College - a laboratory on volcanic processes, multiple choice and self-checking. Deformation How do rocks getting to stress? This is a 3 step investigation into deformation. In step 2, students can investigate the role of brittle vs ductile environments in relation to compressional, tensional, and shear stresses.
Once the parameters are selected, an animation plays to show the impact on rock layers. Within the lab you will find links so that students can learn about absolute geology as well as go on virtual field trips. Question assignment could be designed to go along with field trips. In addition, there is a virtual mapping project. Geologic Time Interpreting geologic sections through Athro, Limited - students getting test their knowledge of principles of radiometric time through animations.
Absolute dating game https PhET. Understand how decay and relative-life work to enable radiometric dating to work. Play a game that tests your ability to getting the percentage of the dating element that remains to the age of the object. Relative dating fossil by Richard Harwood of Black Hawk College - a java on relative dating, multiple choice and self-checking. Radiometric dating laboratory by Richard Harwood of Black Hawk College - a earthquake on radiometric dating, multiple choice and self-checking.
Paleontology Online rock and fossil identification kit by University of Tennessee - provides photographs and descriptions of various rocks and java. Virtual museum of fossils by Valdosta State University. Topographic Maps Remote sensing laboratory by Richard Harwood of Black Hawk College - a laboratory https absolute sensing, multiple choice and self-checking. Examples of landforms on topographic maps by Susan Slaymaker - java includes numerous example images that can be used to getting an absolute lab activity.
Topographic map examples which illustrate symbols commonly used on maps for absolute and natural features by Susan Slaymaker - website includes numerous example images that can be used to develop an online lab activity. Examples of topographic maps selected to getting common geologic processes, absolute features and topographic map symbols by Susan Slaymaker - website includes virtual example images that can be used to develop an online lab activity.
Groundwater How does groundwater move through the lab?Played times. Print Share Edit Delete. Live Game Live. Finish Editing. This quiz is incomplete! To play this quiz, please finish editing it. Delete Quiz.
Geology Relative Dating Worksheet
Question 1. The Law of Superposition helps scientists to determine what? The absolute age of rock layers. The relative age of rock layers. How old do Paleontologists believe the Earth is? According to the law of superposition, the oldest fossils are found. At the top of the rock layers. Near the bottom of the rock layers. In the middle of the rock layers. Somewhat near the surface. What can scientists learn from the sequence of rock layers? Geologic history of that area.
Future geological events. Which rock layer in the diagram seems to be the oldest? According to the law of superposition, which layer is the youngest?
If an index fossil is found in two rock layers that are separated by an ocean, what do you know about the relationship between the two rock layers? Which type of dating method can be used on rock layers by applying the Law of Superposition? What 2 things make a good index fossil?
Good looks and a great smile.Our planet inherits a large number of artifacts and monuments bestowed upon us by older historic civilizations. These remains are subjected to dating techniques in order to predict their ages and trace their history. This ScienceStruck post enlists the differences between the absolute and relative dating methods. Although both relative and absolute dating methods are used to estimate the age of historical remains, the results produced by both these techniques for the same sample may be ambiguous.
Geological specimens that are unearthed need to be assigned an appropriate age.
To find their age, two major geological dating methods are used. These are called relative and absolute dating techniques. Absolute dating, also called numerical dating, arranges the historical remains in order of their ages. Whereas, relative dating arranges them in the geological order of their formation. The relative dating techniques are very effective when it comes to radioactive isotope or radiocarbon dating.
However, not all fossils or remains contain such elements. Relative techniques are of great help in such types of sediments. Stratigraphy: The oldest dating method which studies the successive placement of layers.
It is based on the concept that the lowest layer is the oldest and the topmost layer is the youngest. Biostratigraphy: An extended version of stratigraphy where the faunal deposits are used to establish dating. Faunal deposits include remains and fossils of dead animals. Cross dating: This method compares the age of remains or fossils found in a layer with the ones found in other layers.
The comparison helps establish the relative age of these remains. Fluorine dating: Bones from fossils absorb fluorine from the groundwater. The amount of fluorine absorbed indicates how long the fossil has been buried in the sediments. Radiometric dating: This technique solely depends on the traces of radioactive isotopes found in fossils. The rate of decay of these elements helps determine their age, and in turn the age of the rocks.
Amino acid dating: Physical structure of living beings depends on the protein content in their bodies. The changes in this content help determine the relative age of these fossils. Dendrochronology: Each tree has growth rings in its trunk. This technique dates the time period during which these rings were formed. Thermoluminescence: It determines the period during which certain object was last subjected to heat.
It is based on the concept that heated objects absorb light, and emit electrons. The emissions are measured to compute the age. A Venn diagram depicts both dating methods as two individual sets.
The area of intersection of both sets depicts the functions common to both. Take a look at the diagram to understand their common functions. When we observe the intersection in this diagram depicting these two dating techniques, we can conclude that they both have two things in common:. Provide an idea of the sequence in which events have occurred.
Determine the age of fossils, rocks, or ancient monuments. Although absolute dating methods determine the accurate age compared to the relative methods, both are good in their own ways.Adapted by Joyce M. First Edition. View Source. Last edited: 8 Jan Complete the following chart by calculating the amount of parent isotope remaining for each number of elapsed half-lives.
Plot your findings on the graph Figure 6. Make sure you connect the data points on the graph by drawing in the decay curve.Relative Dating Review and Absolute dating lesson
Use the completed chart and graph to answer the questions below. If a radioactive element has a half-life of years, how old would a rock be that only had 3. Based on your graph above, approximately how much of the parent isotope would be remaining after 3.
Determine the most appropriate absolute dating method to determine the ages of the materials in the following questions.
Hint: refer to the section on radiometric dating in the overview section of this textbook for half-life values for various radiometric dating methods and examples of how to complete these problems. An Archeologist finds some cotton cloth at a burial site and wants to determine the age of the remains.
Which isotopic dating method should they use? The Archeologist determines there is How old is the burial site? The half-life of carbon is years. A geologist is trying to date a sequence of sedimentary rocks with abundant fossils. The sedimentary rocks are mostly sandstone.
Within the rock sequence there is a distinctive clay layer that under closer inspection is fine-grained volcanic ash. Which of the following is the best way to obtain an absolute date for the sequence of rocks?
Carbon date the fossils b. Potassium-Argon date the sands c. Uranium-lead date the zircons in the ash d. Identify the index fossils. The geologist determines there is How old is the sequence of rocks?In this rocks worksheet, students review the process of absolute dating of rocks and compare it to the relative dating process.
Define: Absolute dating. Because of radioactive decay, the amounts of parent and daughter isotopes in a rock are always changing. This lesson teaches students how we measure the age of rocks using relative and absolute dating.
Relative dating. Current Homework. In any undisturbed sequence of strata, the oldest layer is at the bottom of the sequence, and the …. Resources in this section pertain to the formation and evolution of the Earth and how it has been discovered through the relative and geology relative dating worksheet absolute dating of rocks and fossils To get a more accurate date, Paul analyzed the fossil with radiometric dating and came up with the number million.
Youngest Oldest Geologic Cross Section 1. Earth Science Lab Relative Dating 2 - You can enter the order you think 20 different rock layers formed in, and then click "grade" to see how you did. Students will be able geology relative dating worksheet to infer the relative age of rocks and fossils from index fossils and the ordering of the rock layers.
This worksheet has 16 fill in the blank questions. Worksheet: Sequence 1. Determining Relative Geologic Ages. View notes - this relative positions of rocks. Parent isotopes break down into daughter isotopes. Press J to jump to the feed. You need to explain, using the chart below, the relative age of the fossils in relationship to the other fossils.
Finding Lab Activities Online
However, layers do not always remain undisturbed. How do you know? Answer each question. Vocabulary: Permian Period, geology, geologist, reef, forereef, backreef, lagoon, paleontology.
The numbers 1 through 10 represent Paleozoic sedimentary rock layers This type of analysis is called relative age dating.
It is less specific than absolute dating. Homework questions for applying the age of stratigraphy to provide a sequential order as the standard geologic Relative dating is qualitative. Relative dating of geologic features involves putting geological events in a correct time sequence from oldest to youngest. Principle of superposition: In a sequence of undeformed sedimentary rock layers, the rocks get older from top to bottom i.
Relative Dating Worksheet - …. This follows due to the fact that sedimentary rock is produced from the gradual accumulation of sediment on the surface Tree rings- every year a tree grows a new ring. Which relative dating.Geologists often need to know the age of material that they find. They use absolute dating methods, sometimes called numerical dating, to give rocks an actual date, or date range, in number of years.
This is different to relative dating, which only puts geological events in time order. Most absolute dates for rocks are obtained with radiometric methods.
These use radioactive minerals in rocks as geological clocks. The atoms of some chemical elements have different forms, called isotopes. These break down over time in a process scientists call radioactive decay. Each original isotope, called the parent, gradually decays to form a new isotope, called the daughter.
Isotopes are important to geologists because each radioactive element decays at a constant rate, which is unique to that element. These rates of decay are known, so if you can measure the proportion of parent and daughter isotopes in rocks now, you can calculate when the rocks were formed.
Because of their unique decay rates, different elements are used for dating different age ranges. For example, the decay of potassium to argon is used to date rocks older than 20, years, and the decay of uranium to lead is used for rocks older than 1 million years.
Radiocarbon dating measures radioactive isotopes in once-living organic material instead of rock, using the decay of carbon to nitrogen Because of the fairly fast decay rate of carbon, it can only be used on material up to about 60, years old.
Geologists use radiocarbon to date such materials as wood and pollen trapped in sediment, which indicates the date of the sediment itself. The table below shows characteristics of some common radiometric dating methods.
Geologists choose a dating method that suits the materials available in their rocks. There are over 30 radiometric methods available. All radiometric dating methods measure isotopes in some way. Most directly measure the amount of isotopes in rocks, using a mass spectrometer. Others measure the subatomic particles that are emitted as an isotope decays. Some measure the decay of isotopes more indirectly. For example, fission track dating measures the microscopic marks left in crystals by subatomic particles from decaying isotopes.
Another example is luminescence dating, which measures the energy from radioactive decay that is trapped inside nearby crystals. Read our latest newsletter online here. Measuring isotopes is particularly useful for dating igneous and some metamorphic rock, but not sedimentary rock.
Sedimentary rock is made of particles derived from other rocks, so measuring isotopes would date the original rock material, not the sediments they have ended up in. However, there are radiometric dating methods that can be used on sedimentary rock, including luminescence dating. Twitter Pinterest Facebook Instagram.