Scientists also use direct evidence from observations of the rock layers themselves to help determine the relative age of rock layers.
These major concepts are part of the Denver Earth Science Project's "Paleontology and Dinosaurs" module written for students in grades 7-10.
The module is an integrated unit which addresses the following National Science Education Standards: *Science as Inquiry: Students develop the abilities necessary to do scientific inquiry identify questions, design and conduct scientific investigations, use appropriate tools and technologies to gather, analyze and interpret data, think critically and logically to make the relationships between evidence and explanations, communicate results, and use mathematics in all aspects of scientific inquiry.
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.
*Life Science: Fossils indicate that many organisms that lived long ago are extinct.
Extinction of species is common; most of the species that have lived on the earth no longer exist.
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.
*Earth and Space Science: Fossils provide important evidence of how life and environmental conditions have changed.
The complete "Paleontology and Dinosaurs" module takes approximately four weeks to teach. " activity is a 30-minute introduction to geologic time.
By matching partial sequences, the truly oldest layers with fossils can be worked out.