Exploring Geologic Time

Flashcards covering key concepts and information from the lecture on Geologic Time.

What is geologic time?

The events of earth history through time as they relate to the rocks that make up our planet.

What do fossils in rocks help to understand?

Fossils provide a record of prehistoric life and help to reconstruct the environmental conditions of the past.

Who is considered the father of geology?

Blessed Nicholas Steno is known as the father of geology, paleontology, and stratigraphy.

What does the Law of Superposition state?

The oldest layers of rocks are at the bottom and the youngest are at the top.

What is the significance of radiometric dating?

Radiometric dating allows scientists to assign actual ages to rock layers and events in earth history.

What eons make up the Precambrian?

The Precambrian is made up of the Hadean, Archaean, and Proterozoic eons.

What characterizes the Phanerozoic Eon?

The Phanerozoic Eon, from approximately 542 million years ago to present, is characterized by the presence of most fossils.

What major geological eras are in the Phanerozoic?

The major geological eras in the Phanerozoic are Paleozoic, Mesozoic, and Cenozoic.

What is the Law of Inclusions?

If rock fragments are found within another rock, the fragments are older than the rock they are contained within.

What does 'half-life' refer to?

Half-life is the amount of time it takes for half of a radioactive parent isotope to decay to a daughter isotope.