👉 Salinas are a type of soil structure that occurs in the lower layers of a river or stream. They are composed of fine-grained silts, silted sands, and clay sediments deposited over time by water flowing through the soil. Salinities can range from very low to extremely high, depending on the depth and composition of the soil. Salinas are important for supporting aquatic life, as they provide a safe environment for fish to swim, and also contribute to the health of the