GEOLOGIC TIME: UNDERSTANDING EARTH’S PAST

Historical Geology & Paleontology

Earth’s History A story told in the rock layers

But some chapters are missing 550 millions yrs. Ago to present

GEOLOGIC TIME: UNDERSTANDING EARTH’S PAST

Key “Principles” to Reading Earth’s Past Principle of Uniformity Principle of Original Horizontality Principle of Superposition Principle of Crosscutting Relationships Principal of Faunal Succession

Index fossils

GEOLOGIC TIME: UNDERSTANDING EARTH’S PAST

The Fossil Record Methods of fossilization

Non-traditional methods Frozen Amber Tar Mineralization & replacement

Traditional methods Cast & mold

GEOLOGIC TIME: UNDERSTANDING EARTH’S PAST

The Geologic Time Scale (Read from bottom up)

Era (3) Periods (12) Epochs (7)

GEOLOGIC TIME: UNDERSTANDING EARTH’S PAST

Eras Cenozoic – recent life Youngest Mesozoic – middle life Paleozoic – ancient life Oldest

GEOLOGIC TIME: UNDERSTANDING EARTH’S PAST

Periods Quaternary Youngest Tertiary Cretaceous Jurassic Triassic Permian Pennsylvanian Mississippian Devonian Silurian Ordovician Cambrian Oldest

GEOLOGIC TIME: UNDERSTANDING EARTH’S PAST

Epochs Recent Youngest Pleistocene Pliocene Miocene Oligocene Eocene Paleocene Oldest