Geologic Time

Smashing something with a hammer is an example of ___________ weathering. Acid rain breaks down rocks like limestone easily. What kind of weathering is this? Wind and water are great agents of _________ weathering. A stream that carries sediment to the ocean is an example of ___________. The Grand Canyon has been ____________ by water over millions of years.

Order them from longest to shortest The time between… The formation of the Himalayan mountains and today. Dino extinction and today. Origin of the earth and the development of multi-celled organisms.

"Nescire autem quid ante quam natus sis acciderit, id est semper esse puerum.“ "To be ignorant of what occurred before you were born is to remain always a child."

Geologic Time Table Summary of the major events of the Earth’s history. Eras Precambrian or Proterozoic 4,000-600 million years ago. Largest era (87%) Lack of fossil evidence Early single celled organisms

Paleozoic 570 million years old Abundant fossils of both plants and animals from the ocean and land. Known as the “Age of Invertebrates”

Mesozoic 230 million years old Known as the “Age of Reptiles” Dinosaurs thrived.

Cenozoic 65 million years old to present Known as the “Age of Mammals” Humans – last

Era’s are subdivided into periods. Periods are subdivided into epochs.