Earth's Layers and Strata
The Law of __________ says the oldest layers are at the bottom in undisturbed strata.
What is Superposition?
Fossils used to date strata are called __________ fossils.
What are index fossils?
Scientists recognize about how many major mass extinctions?
What is five?
Earth’s outer shell is broken into large moving __________.
What are plates?
This process turns sediments into sedimentary rock.
What are compaction and cementation?
Another word for rock layers is __________.
What is Strata?
Fossils of aquatic plants in deserts suggest these areas were once covered by __________.
What is water (or oceans/seas)?
A mass extinction is a sudden loss of __________ in the fossil record.
What is biodiversity?
The force driving plate movement comes from __________ currents in the mantle.
What are convection currents?
Trilobites are an example of this type of fossil.
What is an index fossil?
Fossils are most commonly preserved in this type of rock.
What is sedimentary rock?
Fossil sequences show a __________ pattern of life forms over time.
What is progressive?
The extinction of the dinosaurs at the end of the Cretaceous was caused by this.
What is an asteroid impact?
Fossils of Glossopteris found on multiple continents support the existence of __________.
What is Pangaea?
Modern whales evolved from ancestors that once lived on __________ and __________.
What are land and water?
The crust and upper mantle form this rigid outer layer.
What is the lithosphere?
In __________ rocks, fossils are often destroyed due to heat and pressure.
What are metamorphic rocks?
Higher oxygen levels in the past allowed insects to grow much __________ than today.
What is larger?
At this type of boundary, one plate sinks beneath another.
What is a convergent (subduction) boundary?
Fossils help show that __________ has occurred over Earth’s history.
What is evolution?
The softer layer below the lithosphere where plates move is called the __________.
What is the asthenosphere?
The fossil record provides evidence that organisms share a common __________.
What is ancestor?
Name two causes of mass extinctions besides asteroid impacts.
What are climate change and volcanic activity?
Fossils of marine organisms found high in mountains are evidence that tectonic forces have __________ the land.
What is uplifted?
Which is harder to predict: earthquakes or hurricanes? Explain why.
What is earthquakes, because they have no reliable warning signs compared to hurricanes tracked by satellites.