Types of Rock
Sedimentary, Igneous, and Metamorphic
Strata means "layers"
What is weathering?
Weathering is the chemical and physical processes that break down rocks at Earth's surface
What is deposition?
The process of depositing sediment that has been moved by erosion.
What does the term 'relative dating' mean?
Relative dating is a way scientists figure out the age of rocks and fossils by looking at where they are found in the ground. It doesn’t tell the exact age in years, but it helps put things in order from oldest to youngest.
Which type of rock forms from cooled magma or lava?
Igneous Rock
What is a fossil?
A fossil is the remains or traces of ancient plants and animals
Name two types of weathering. (Hint: remember your comic strip notes)
Biological (animals burrowing, roots growing)
Chemical (acid rain, oxidation/rusting)
Physical (frost wedging, abrasion)
What is a landform that is formed by deposition? Think about our Blooket review... there was a picture of this feature.
A delta is an example of a landform created by deposition.
What is the geologic time scale?
A timeline that organizes Earth’s history through different eras and periods.
What is the name of the type of rock formed through high heat and high pressure?
Metamorphic Rock
What type of rock usually contains fossils?
Sedimentary rocks typically carry fossils because they are made of layers of sediments that build up over time.
How does weathering differ from erosion?
Weathering is what breaks down rocks. Erosion is when water, wind, ice, or other forces move rocks and sediment.
Weathering does the breaking, erosion does the taking
Explain how human actions can impact deposition in rivers.
Construction and damming can change water flow and affect where sediments are deposited. Pollution can also affect deposition in rivers.
What does the term 'mass extinction' mean?
Mass extinction is a widespread and rapid decrease in the number and variety of animals on Earth.
What needs to happen for a sedimentary rock to transform into a metamorphic rock?
It would need to go under high heat and high pressure.
What can fossils tell us about the past?
They provide evidence of what the environment was like and what organisms lived there
Define 'erosion' and name two types of erosion
Erosion is the process where wind, water, ice or other forces MOVE rocks/sediment.
Types include: wind, water, glaciers, gravity
What is the law of superposition and why is it important for scientists?
The Law of Superposition states that in undisturbed rock layers, the oldest layers are at the bottom. It's important because it helps us understand Earth's history. It teaches us about the plants and animals that used to live here and important events that have happened.
Earth is about 4.6 billion years old!
Which rock is formed from compaction and cementation?
Sedimentary rocks
How can geologists use strata to learn about Earth's history?
Strata can give us clues about different periods in time and the plants and animals that lived millions of years ago. It can also help us understand our planet and predict what might happen in the future.
Describe ways water can contribute to weathering?
Water can seep into cracks in rocks, freeze overnight, and eventually cause the rocks to crack and break.
If you wanted to find the oldest fossil, where would you dig?
The farther down you dig, the older the materials and fossils you will most likely find.
What are the four major eras in Earth's geologic time scale? You can use your notes!
Precambrian, Paleozoic, Mesozoic, and Cenozoic