Earth's History Unit Test-8th Grade

Data from the analyses of ice cores has shown that levels of carbon dioxide have increased and decreased over the last 400,000 years. Based on this information, what can be inferred about global temperatures over the same period of time?

• Temperatures have risen sharply over the time period.
• Temperatures have dropped sharply over the time period.
• Temperatures have remained constant over the time period.
• Temperatures have risen and dropped in a repeated pattern over the time period.

Which of these provides the BEST evidence that the environment of Earth has changed over millions of years?

• active migration of sand dunes
• polished appearance of rock surfaces
• marine fossils found in mountains
• bones of animals found on the ground

The diagram shows the Earth’s crustal plates. Which is true about geologic evolution in reference to plate tectonics?

• The plates of Earth have settled and finished moving.
• The movement of plates has caused the formation and break-up of continents over time.
• The movement of the plates is responsible for all geologic changes that occur on Earth.

Which part of Earth’s history i best shown by analysis of ice cores?

• changes in climate
• changes in plant growth
• changes in the amounts of precipitation
• changes in the formation of rock layers

Which best describes the criteria necessary for a fossil to be used as an index fossil?

• The fossil must be from a mammal.
• The fossil must be found both in rock layers on the land and in rock layers under the oceans.
• The fossil must be found in areas on Earth and must be from an organism that lived for a relatively short time span.
• The fossil must be found in at least three different types of sedimentary rock layers and at least two different types of igneous rock layers.

Which is the best example of an index fossil?

• corals found in rock layers worldwide
• dinosaur bones found only in Australia
• footprints of different types of dinosaurs
• casts of bird feathers found in all layers of rock in an area

Which statement best describes the Law of Superposition?

• Each sedimentary layer of rock represents 1,000 years of Earth’s age, much like the rings of a tree.
• In undisturbed layers of sedimentary rock, the upper rock layers are older than the lower rock layers.
• In undisturbed layers of sedimentary rock, the lowest layers contain the older rocks.
• Rocks that form near volcanoes are older than surrounding rock.

Which best describes how ice cores are important to the study of geologic history?

• They show unconformities, which signal changes in deposition.
• They hold index fossils, which are used to date the different ice cores.
• They contain evidence showing changes in the atmospheric composition over time.
• They follow the Law of Superposition, which gives reasons for extinctions of species.

Which is the most likely reason scientists would want to analyze the air trapped in an ice core?

• to study how much oxygen was in the ice
• to learn how the atmosphere changed over time
• to determine how many gas bubbles were present in the air
• to study how many animals lived on Earth when the ice was formed

Fossils were discovered in four different sedimentary rock layers as shown. Which best describes the age of the fish relative to the age of the fern and the age of the shell?

• The fish is older than both the fern and the shell.
• The fish is younger than both the fern and the shell.
• The fish is older than the fern, but younger than the shell.
• The fish is younger than the fern, but older than the shell.