Lecture Notes: Exercise #4 - "Which Way is Up?"

Overview

• Objective: Learn to determine basic geological ordering and layering.
• Activity: Watch a movie, read an article, and answer 6 questions.
• Grading: Out of 12 points, automatically graded with no time limit.
• Submission: One chance to submit; proof answers carefully.

Technical Cautions

1. Do not open a new browser window while taking the quiz.
2. Double-check your answers before submission.
3. Avoid using the mouse wheel to prevent accidental changes to answers.

Geological Concepts

Determining Geological Ordering and Layering

• Sediment Layers: Typically horizontal due to gravity.
• Sedimentary Rock Formation: Layers can be tipped or turned due to mountain-building processes.
• Age Determination: Younger layers are deposited on top of older layers.

Mud Layers

• Disturbances: Mud layers can have footprints, cracks, raindrop imprints.
• Cracks and Footprints: Indicate the top side of the layer when formed.

Sand Dunes

• Layer Orientation: Dunes have steeper layers near the top, flattening at the bottom.
• Cross Beds: Indicate the direction of growth and which side was up.

Shells

• Orientation: After clams die, shells tend to settle in a stable orientation (hollow-side down).

Lava

• Bubble Formation: More and bigger bubbles are found near the top of the lava flow.
• Frozen Layer: Top is often identified by the presence of a thin frozen layer.

Shadows, Hills, and Holes

• Shadow Identification: Understanding shadow direction helps distinguish between hills and holes.

Review and Practice

• Review Video: Additional resource for understanding the concepts.
• Exercise: Identify "which way was up" for rock layers in given images.

Additional Resources

• Module 9 Preview: Further reading and learning available for deeper understanding.

Key Takeaways

• Ensure understanding of geological layering and orientation.
• Use visual cues like cross beds, shell orientation, mud disturbances, and shadow direction to determine original layer orientation.
• Carefully review all materials before attempting the exercise.