Geologic Time
The longest division of geologic time
Igneous Rocks
A tool that gives us important information about past life
Fossil Record
A type of dating that compares rocks or fossils by classifying it as "older" or "younger" than other rocks/fossils
Relative Dating
A break in the rocks that make up Earth's crust
Fault
Our current era (appearance of humans)
Cenozoic
This rock makes up 75% of the rocks on Earth's surface
Sedimentary rocks
Name two materials that are best for fossil formation
bones, bark, tusks, leaves
Law of Superposition
The half-life of carbon-14 is 5,700 years. How much time has passed after 2 half-lives?
11,400 years
The divisions of time from longest to shortest
Eon, Era, Period, Epoch
Intrusion
Forms when sediments bury an organism and the sediments change into rock; organism decays leaving a cavity in the shape of the organism
Mold fossil
Have trapped chemicals and air that can tell us the climate conditions at the time of formation
Ice cores
A fault where two pieces of land move horizontally
Strike slip fault
Reptiles were the dominant animals of this era, including the dinosaurs
Mesozoic Era
Process when rocks are broken into smaller pieces
Weathering
Forms when minerals soak into the buried remains, replacing the remains, and changing them into rock
Petrified fossil
Helps scientists estimate how long ago rocks formed and the ages of fossils within those rocks by looking at the radioactive element's decay rate
Radiometric Dating
Major fault located in California
San Andreas Fault
5 major events were formation of light, Earth, atmosphere, oceans, and life
Precambrian Era
Three erosion agents
Wind, water, animals
What can fossils tell us about the past?
Clues to the diversity of living things over the history of Earth, past climate and surface changes on Earth, changes that have occurred with organisms over time
The best element for dating fossils that are younger than 50,000 years
Carbon-14
Locations where ice cores are collected