Question

According to Dunham’s classification, which one of the following limestones is grain-supported and contains mud?

• A. Wackestone
• B. Packstone
• C. Grainstone
• D. Mudstone

Hint:

To classify limestones, focus on the proportion of grains and mud. The key difference between Packstone and Grainstone is the presence of mud in Packstone.

Answer 1

The Correct Option is B

Step 1: Understand Dunham’s Classification.
Dunham’s classification of limestones is based on the amount of mud and the grain-supported nature of the limestone.
- Wackestone: Mud-supported limestone with grains embedded in mud.
- Packstone: Grain-supported limestone with mud filling the intergranular spaces.
- Grainstone: Grain-supported limestone with minimal or no mud.
- Mudstone: Mud-supported limestone without significant grains.
Step 2: Identify the Correct Limestone Type.
A Packstone is grain-supported and contains mud, making it the correct classification for this question.
Thus, the correct answer is Packstone. Final Answer: \[ \boxed{\text{Packstone}} \]