INTRODUCTION Scientists have good evidence that the earth is very old, approximately four and one-half billion years old.
Scientific measurements such as radiometric dating use the natural radioactivity of certain elements found in rocks to help determine their age.
To her, the relative importance of the farm to Billy was as simple as a problem in addition.
I might be said to be without a friend, or relative, in the world.
There lay your relative on his back behind the curtain, plunged in sweet slumber.
This also means that fossils found in the lowest levels in a sequence of layered rocks represent the oldest record of life there.In this activity, students begin a sequencing activity with familiar items letters written on cards.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.*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.
For example, most limestones represent marine environments, whereas, sandstones with ripple marks might indicate a shoreline habitat or a riverbed.