In archaeology, excavation was the act of digging to expose and retrieve something from underground.
In 2268, Triacus was the site of a scientific colony assembled by the Starnes Exploration Party, lead by Professor Starnes. On stardate 5038.3, one of the archeologists, Professor Wilkins, accidentally released Gorgan during an excavation of a cave near their encampment. It was noted that the destruction of whatever civilization that might have been there was produced by some natural catastrophe. (TOS: "And the Children Shall Lead")