Toya no Kubi
A glimpse of the Goto Islands’ underlying structure
Toya no Kubi, a hilly peninsula in north-central Fukue Island, is important because the rock structure is completely exposed. The clearly visible bands across its side show the tremendous forces of crustal deformation and illustrate the structure of the Goto Islands.
The Goto Group is the name given to the foundational land masses that moved down from continental Asia. Here the steep hills meet the newer black rhyolitic lava flows to the west. The Group is broken by a fault running from northeast to southwest, clearly visible in the steep vertical tilting of the structural layers on the east side of the peninsula. At an exposed area near the neck of the peninsula, footprints, most likely of an early alligator, are visible in the exposed sedimentary rock.
As the entire process of deformation is clearly visible, this is a unique and very valuable place for researchers to study the structure and development of the Goto Islands.
The older, higher formations of the peninsula’s basalt formations, along with the younger, flatter lava flow of the Gyogasaki Peninsula, created Shiraishi Bay. This has long been used by ships seeking refuge from the typhoons and other storms that sweep up from the southern Pacific. Those who have sought shelter over the years include Buddhist priests and merchants who stopped at the peninsula on their way to China some 1,000 years ago.