Final answer:
Cuneiform tablets are the most commonly encountered documents in Mesopotamian archaeology, providing insight into various aspects of ancient Mesopotamian culture.
Step-by-step explanation:
The type of document frequently encountered in the writings recovered in Mesopotamia is the cuneiform tablet. The Mesopotamians were known for their innovative form of writing, cuneiform, which was inscribed on clay tablets. These tablets are significant historical artifacts that have provided a wealth of knowledge about the social, religious, and economic life in ancient Mesopotamia. Developed around 3000 BCE, cuneiform began as pictographs and evolved over time into a script that could record various languages through wedge-shaped symbols. These tablets were not only used for recording everyday transactions and events but also for royal inscriptions, law codes, treaties, literature, and more. Archaeologists have uncovered a vast number of these tablets, which often were baked to ensure durability.