Question

Based on the size and shape of the clasts in the sedimentary rock shown in the image, which classification would geologists most likely apply to the rock?
Question 4 options:

A)

Breccia

B)

Sandstone

C)

Conglomerate

D)

Mudrock

Answer 1

To accurately classify the sedimentary rock based on the size and shape of the clasts, you would generally consider the following:

- **Breccia**: Composed of large, angular clasts.
- **Sandstone**: Made primarily of sand-sized particles (0.063 to 2 mm) and has a granular texture.
- **Conglomerate**: Contains larger, rounded clasts.
- **Mudrock**: Generally has very small particles (clay and silt) and may include shale.

If the clasts are large and angular, the rock would likely be classified as **A) Breccia**. If the clasts are rounded and larger, then it would be classified as **C) Conglomerate**. If the rock is composed of sand-sized particles, then it would be **B) Sandstone**. If it is primarily small particles, then it would fit into **D) Mudrock**.

Without seeing the image, if the clasts are large and angular, go with A) Breccia. If they are rounded, choose C) Conglomerate.