Complex sentence: Cariou participated at the 1912 Summer Olympics held in Stockholm, where he won a gold medal in the individual jumping, a silver medal in team jumping, and a bronze medal in individual three-day eventing with the horse "Cocotte".
Split into simpler sentences: Cariou participated at the 1912 Summer Olympics held in Stockholm, where he won a gold medal in Individual Jumping. He received a bronze medal in individual Three-day Eventing with the horse "Cocotte".