Earth's History Study Guide
Geologists
William Smith
Charles Darwin
James Hutton
Nicolaus Steno
Hutton concluded that strata take thousands of years to form
The idea that older rock layers are farther from the surface inspired Darwin's work on evolution.
William Smith connected strata in different locations by recognizing similar patterns of fossils
Steno proposed 3 laws: the law of superposition, horizontality, and cross-cutting relationships.
Rock Cycle
Types of rocks
Igneous
Sedimentary Rock
Metamorphic
Fossils usually found in these rocks
Compaction and cementation of sediments
Used for relative dating
Created through magma cooling and solidification
Used for absolute dating
Changed by heat and pressure
Form stratas
Comparison to other fossils and rocks (Not actual age)
Uses years to identify the ages of rocks and fossils (MYA, BYA)
Geologic Timescale
Eras
Can be compared to as a clock
Periods
Epochs
More than 3 million years
100s of millions of years
10s of millions of years
a system of chronological dating that classifies geological strata in time
Used by Geologists, Paleontologists and other Earth Scientists.