Geologic dating lesson
This lesson is based on an online booklet that provides an introduction to the study of earth's history, published by the USGS.Using careful analogies and written historical records, the authors help students understand the development of the geologic time scale, including how this depended on gathering evidence and making comparisons.Prerequisite knowledge for this lesson includes the idea that: "Sediments of sand and smaller particles (sometimes containing the remains of organisms) are gradually buried and are cemented together by dissolved minerals to form solid rock again." (, p.73.) Concepts covered in this lesson, including geologic history, age dating, plate tectonics, timelines, and fossils are prerequisite concepts for understanding the theory of evolution, which is another topic taught at this grade level.One chapter called Fossil Succession, found in the online booklet Fossils, Rocks, and Time, is particularly useful in helping students understand that the basic idea of biological evolution is that the earth's present-day species developed from earlier, distinctively different species. 125.) Specifically, it helps students understand that the kinds of animals and plants found as fossils change over time.It discusses how Darwin's theory gave scientific meaning to the observed succession of once-living species in the record of earth's history preserved in the rocks.
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.Relative age dating also means paying attention to crosscutting relationships.Say for example that a volcanic dike, or a fault, cuts across several sedimentary layers, or maybe through another volcanic rock type.Geology, a major academic discipline, also plays a role in geotechnical engineering.The majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth.