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.PALEONTOLOGY, AND in particular the study of dinosaurs, is an exciting topic to people of all ages.
After the uplift of the land, the forces of erosion attacked the highlands and the eroded rock debris was transported and redeposited in the lowlands.
Certain layers are in the form of sand bars and gravel banks - rock debris spread over the land by streams.
Some rocks were once lava flows or beds of cinders and ash thrown out of ancient volcanoes; others are portions of large masses of once-molten rock that cooled very slowly far beneath the Earth's surface.
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.
An isotope system is assumed to be a closed system with regard to the parent and daughter - they remain within the system and do not leave it, and at the same time no isotopes of the parent or daughter type enter the system from outside.