Geologic dating principles
To use multiple lines of data to assess the certainty of dating estimates. Introduce the concept of time and how we measure it.
To use radiometric dating methods (half-life and parent-daughter ratio) to generate hypotheses about the ages of rocks.
Use in-class demonstrations/analogies of the concept of radioactive decay. Utilize Student Response System, or Clickers during lecture: Inserting questions at the end of each conceptual module within the lecture(s), including a question at the beginning and the end about their comfort level with the age estimates that they've heard about deep time (e.g., dinosaur fossil, a weathered rock) 2.
Reflective learning assessment, or metacognition: At the end of the lecture(s), ask students what was 1) the most important, 2) the most interesting, 3) the most confusing, and 4) something they want to know more about. Skills assessment: For an example "rock," students will be asked to count items to calculate parent-daughter ratio, given a plot of the decay, determine the age of the sample, and determine if it makes sense in the geological context, and place the date in its appropriate place in the geological time scale. Concept Map: At the end of the lecture ask students to create concept maps to demonstrate how a list of key words are related. Possible exam questions: 1) Given a number of parent and daughter ratios and a half-life of a particular isotopic system, students should calculate the age of a rock, and place that age on the Geological Time Scale in a period or time boundary; 2) Students should know the appropriate isotopic sytem(s) that could be used for a particular age; e.g.
That can lead to the fact that there is a basic physical process behind radioactive decay as well.
Unlike people, you can’t really guess the age of a rock from looking at it.
Yet, you’ve heard the news: Earth is 4.6 billion years old. That corn cob found in an ancient Native American fire pit is 1,000 years old. Geologic age dating—assigning an age to materials—is an entire discipline of its own.
To gain confidence in using geochronological dating tools to understand the history of the earth To apply the concept of time measurement across time scales.
To learn how dates obtained from radioactive dating are verified 5.