Introduction To Geologic Time
The Geologic Time Scale is the 4.6 billion year history of earth, the Geologic Time Scale is sometimes referred to as “deep time”. The geologic time scale is broken up into smaller divisions for describing geologic time, those divisions are Eons, Eras, Periods, Epochs and age.
Before scientists had the technology to determine the absolute age of rocks the developed a Relative Geologic Time Scale, they had no way of knowing the ages of individual rock layers. But by using relative dating scientists were able to tell the correct sequence of rock layers formation. Scientists used relative dating of rocks to unravel Earths complex history. Later in the 20th century radioactive dating was able to give us the age of rocks in years.
Fossils and Fossil Record
Fossil are preserved remains or traces of living things. The Fossil Record is a record of life on Earth. The Fossil Record is used as evidence of Earth’s changing past because the Fossil Record can show formations, evolutions, and extinctions within Eras of Earth’s history.
Law of Superposition
The law of Superposition states that in any undisturbed rock layer, the youngest layer is at the top and the oldest layer is at the bottom. The Law of Superposition relates to the Geologic Time Scale because, say the oldest layer of rock formed one billion years ago. That date would be recorded as an event in the Geologic Time Scale.
Eras
The Geologic Time Scale is divided into many units of time, one unit of time is called an Era. Scientists determine when an Era ends and another begins by examining a rock layer, then looking for significant changes within that rock layer and finally comparing those significant changes to other rock layers changes.
Resources:
www.esse.ou.edu/fund_concepts/Fundamental_Concepts4/Geologic_Time_Scale.html#About
www.enchantedlearning.com/subjects/dinosaurs/glossary/TimeScaleShort.html
www.scienceviews.com/dinosaurs/geologictime.html
www.sweetsearch.com
The Geologic Time Scale is the 4.6 billion year history of earth, the Geologic Time Scale is sometimes referred to as “deep time”. The geologic time scale is broken up into smaller divisions for describing geologic time, those divisions are Eons, Eras, Periods, Epochs and age.
Before scientists had the technology to determine the absolute age of rocks the developed a Relative Geologic Time Scale, they had no way of knowing the ages of individual rock layers. But by using relative dating scientists were able to tell the correct sequence of rock layers formation. Scientists used relative dating of rocks to unravel Earths complex history. Later in the 20th century radioactive dating was able to give us the age of rocks in years.
Fossils and Fossil Record
Fossil are preserved remains or traces of living things. The Fossil Record is a record of life on Earth. The Fossil Record is used as evidence of Earth’s changing past because the Fossil Record can show formations, evolutions, and extinctions within Eras of Earth’s history.
Law of Superposition
The law of Superposition states that in any undisturbed rock layer, the youngest layer is at the top and the oldest layer is at the bottom. The Law of Superposition relates to the Geologic Time Scale because, say the oldest layer of rock formed one billion years ago. That date would be recorded as an event in the Geologic Time Scale.
Eras
The Geologic Time Scale is divided into many units of time, one unit of time is called an Era. Scientists determine when an Era ends and another begins by examining a rock layer, then looking for significant changes within that rock layer and finally comparing those significant changes to other rock layers changes.
Resources:
www.esse.ou.edu/fund_concepts/Fundamental_Concepts4/Geologic_Time_Scale.html#About
www.enchantedlearning.com/subjects/dinosaurs/glossary/TimeScaleShort.html
www.scienceviews.com/dinosaurs/geologictime.html
www.sweetsearch.com