Geologic Cross-Section Principles

The video tutorial explains geologic cross-sections, which are two-dimensional representations of Earth's interior, useful for interpreting past geologic conditions. It covers geologic events like depositions and structures such as faults and folds. The tutorial introduces unconformities, periods of non-deposition or erosion, and discusses principles of relative age dating. An example of a geologic cross-section is analyzed, demonstrating how to determine the sequence of events using principles like horizontality, superposition, and cross-cutting relationships.

What is the primary purpose of geologic cross-sections?

• To predict future volcanic eruptions

• To interpret past geologic conditions and relative ages

• To measure the current temperature of the Earth's core

• To create three-dimensional models of the Earth's surface

Which of the following is NOT a type of geologic event?

• Metamorphic transformation

• Magnetic field reversal

• Igneous formation

• Sedimentary deposition

What is an unconformity in geology?

• A type of fault

• A type of sedimentary rock

• A period of non-deposition or missing time

• A volcanic eruption

Which principle helps determine that the oldest layers are at the bottom in a sequence of sedimentary rocks?

• Principle of Lateral Continuity

• Principle of Original Horizontality

• Principle of Superposition

• Principle of Cross-Cutting Relationships

In the example of a geologic cross-section, what does the feature labeled 'D' represent?

• A sedimentary layer

• An igneous dike

• A metamorphic rock

• A fault line

What is the correct order of events from oldest to youngest in the given geologic cross-section example?

• E, D, C, B, A

• D, E, A, B, C

• C, B, A, D, E

• A, B, C, D, E

Which principle is used to determine that 'D' is older than 'E' in the cross-section?

• Principle of Superposition

• Principle of Cross-Cutting Relationships

• Principle of Lateral Continuity

• Principle of Original Horizontality

What type of fault is identified in the cross-section example?

• Thrust fault

• Normal fault

• Reverse fault

• Strike-slip fault

Which principle states that layers of sediment are originally deposited horizontally?

• Principle of Lateral Continuity

• Principle of Cross-Cutting Relationships

• Principle of Original Horizontality

• Principle of Superposition

What does the principle of cross-cutting relationships help determine?

• The type of rock present in a layer

• The sequence of events in a geologic cross-section

• The original orientation of sedimentary layers

• The age of a rock layer compared to others