Question

1. According to the pictures, how did layer C form?

2. Which is the oldest layer in this rock section? Explain your reasoning.

3. Is layer B older or younger than layer C? Explain your reasoning.

Answer 1

1. Layer C formed through sedimentation or deposition processes.
2. The oldest layer is the bottommost layer (Layer A) as it is the first to be deposited, following the principle of superposition.
3. Layer B is older than layer C; the principle of cross-cutting relationships indicates that B cuts across C, making B the older layer.

The rock section presents a dynamic geological history, and the formation of Layer C is inferred to be a result of sedimentation or deposition processes. The layer-by-layer sequence, with the oldest layer, A, at the bottom, follows the fundamental geological principle of superposition, which states that newer layers are deposited on top of older ones. Therefore, Layer A represents the initial deposition, and subsequent layers, including C, followed over time.

In terms of age determination within the rock section, Layer A holds the distinction of being the oldest, as it serves as the foundational base upon which subsequent layers were deposited. This adherence to the principle of superposition allows for a chronological understanding of the rock layers, with each succeeding layer representing a newer episode in the geological timeline.

Regarding the relationship between layers B and C, the principle of cross-cutting relationships plays a crucial role. Layer B cuts across Layer C, indicating that B is the older layer and C formed subsequently. This cross-cutting relationship provides valuable insights into the geological events that shaped the rock section, unraveling the intricate narrative of Earth's dynamic processes over time.