What is relative dating of fossils

The Smithsonian Institution's Human Origins Program

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.

REGISTER TO VIEW

Fossils can provide clues to how plants and animals lived in the past — what they looked like, what they ate, what environments they lived in, and how they evolved and went extinct. About 3 million years ago, a new type of clue appeared in the rock layers of eastern Africa — objects made by our hominin ancestors. Hominins began to live their lives in a different way, utilizing tools made of stone in their day-to-day activities.

REGISTER TO VIEW

Allmon and Robert M. Ross Answering this frequently encountered question in geology requires two separate steps. They correspond to two different ways that we express how old something or someone is in our everyday experience.

REGISTER TO VIEW

Exploring Our Fluid Earth

Relative dating is used to arrange geological events, and the rocks they leave behind, in a sequence. The method of reading the order is called stratigraphy layers of rock are called strata. Relative dating does not provide actual numerical dates for the rocks. Next time you find a cliff or road cutting with lots of rock strata, try working out the age order using some simple principles:. Fossils are important for working out the relative ages of sedimentary rocks.

REGISTER TO VIEW

REGISTER TO VIEW