Which of the following best describes the compositional layers of the earth?
Explain what differentiates the Earth’s crust and lithosphere.
The crust is Earth’s outermost solid layer. The lithosphere is the rigid outer layer that includes the crust and the uppermost part of the mantle; it is broken into tectonic plates.
The Earth’s crust is principally composed of _______.
The core of the Earth is mostly composed of _______.
Explain how fossil fuels found in the Earth’s crust are ultimately the result of biological processes.
Fossil fuels began as the remains of living organisms, such as ancient plants, algae, and other organisms. After these remains were buried by sediment, heat and pressure transformed them over millions of years into coal, oil, and natural gas.
Explain how ocean ridges and trenches are formed.
Ocean ridges form where tectonic plates move apart. Magma rises through the gap, cools, and solidifies to form new oceanic crust. Trenches form where plates converge and one plate, usually oceanic crust, bends and sinks beneath another plate into the mantle.
Explain how biogeochemical cycles and the rock cycle are important for life on Earth.
Biogeochemical cycles move and recycle essential elements, such as carbon, nitrogen, and phosphorus, among living things, the atmosphere, water, and rocks. The rock cycle forms and transforms rocks, storing and releasing minerals and nutrients through processes such as weathering. Together, these cycles help provide organisms with the materials they need and maintain conditions that support life.
Explain how oceanic crust is continuously created at mid-ocean ridges.
At mid-ocean ridges, tectonic plates move apart. Hot mantle material rises to fill the space, melts into magma, and erupts or intrudes along the ridge. The magma cools and solidifies into new oceanic crust, while older crust is pushed away on either side.
Rheology is best described as the study of _______.
The continental crust covers _______ of the Earth’s surface.
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