A core barrel is a cylindrical tool used in geological drilling to extract a cylindrical sample of soil or rock, known as a core. This device is essential for studying the subsurface materials and understanding geological formations. The core barrel is typically attached to a drilling rig and can reach significant depths, allowing scientists to analyze the Earth's layers. The core collected by the core barrel provides valuable information about the composition, structure, and history of the Earth's crust. Researchers use these samples to investigate natural resources, assess environmental conditions, and study geological processes, contributing to fields like geology, mining, and environmental science.