Short answers, pulled from the story.
The Descartes Highlands sits on the near side of Earth's Moon, surrounding a feature named Descartes crater. This area covers much of the near side and includes prominent Cayley and Descartes formations.
Commander John Young and his crew found rocks that were not volcanic in origin but rather breccias composed of fragments from several lunar impacts. These rocks likely came from debris generated by large impact events like the one forming Mare Nectaris.
Mission planners selected the Descartes Highlands before 1972 to investigate different materials than those found in Lunar mare regions. The selection process prioritized finding evidence of ancient history rather than volcanic activity.
Astronauts John Young and Charles Duke traveled to Sudbury Ontario in July 1971 to examine shatter cones left by a large meteor impact. They used these field observations to validate their lunar impact hypotheses and prepare for interpreting complex geological data.
John Young and Charles Duke drove across North Ray and South Ray craters during their mission to sample material directly from these locations. Their routes allowed them to access naturally excavated samples from both Cayley and Descartes layers.