Here's a breakdown:
* Clay: Clay is a fine-grained sediment, composed of tiny mineral particles.
* Packed clay: When clay is deposited in layers and compressed by the weight of overlying sediments, it becomes tightly packed.
* Mudstone: As the packed clay experiences further compaction and cementation (where minerals precipitate between the clay particles), it turns into mudstone. Mudstone is a hard, fine-grained sedimentary rock.
It's important to note that mudstone is just one possible outcome. Other factors like the presence of other minerals, the degree of compaction, and the specific clay composition can lead to other types of sedimentary rocks like shale or siltstone.
