Question

Determine the order of the geologic events that generated the rock outcrop in the diagram. The letters represent

sedimentary layers, except for B and E, which represent faults. 1 should represent the oldest event and 9 should
represent the youngest.
Prompts

Answer 1

The order of geologic events are:

• 1-C,
• 2-A,
• 3-D,
• 4-B,
• 5-E,
• 6-F,
• 7-G,
• 8-H,
• 9-I.

The rock outcrop in the diagram reveals a complex sequence of geological events. The oldest event, marked as 1, corresponds to the deposition of layer C which is the bottom-most sedimentary layer. This indicates that layer C was the first to form and makes it the oldest rock unit in this outcrop.

Following the deposition of layer C, event 2 (A) occurred resulting in the deposition of layer A on top of layer C. This indicates a shift in environmental conditions or sediment source leading to the formation of a new layer.

Event 3 (D) represents another episode of deposition, giving rise to layer D atop layer A. This suggests a continued evolution of the local environment or sedimentary processes.

The subsequent events, 4 (B) and 5 (E), are faults. Fault B displaces layer A, indicating a period of tectonic activity that affected the existing rock layers. Fault E, occurring after fault B, further disrupts the sequence, displacing layers D and A.