2025.12.07

We held an autumn nature walk, ‘Iwa sanpo’!

We held the Oki Nature Museum Nature Observation Walk, ‘Iwa Sanpo’!

During this ‘Iwa Sanpo’ (rock walk), under the theme of ‘Uncovering the origins of the Oki Islands through the lens of rocks’, we examined diatomaceous earth and rhyolite at Okutsudo Beach.
Diatomaceous earth is rock formed when Oki was covered by the sea, whilst rhyolite is rock formed when Oki was a volcanic island.
Diatomaceous earth is rock that was formed when Oki was a subaquatic volcanic island; while being under the sea, the volcanic rhyolite rock was forming

Within the diatomaceous earth, we discovered a beautiful rock called Menilite, which consists almost entirely of Silicone Dioxide😲 .

At Okutsudo Beach, we took a one-way walk for about 20 minutes, inspecting the rhyolite along the way. We observed the ‘flow patterns’—the flow-banded structure—from which the rock derives its name, and all the participants took photographs of their favourite patterns. Photos from the day and pictures of the rhyolite taken by participants are currently on display at the Oki Nature Centre!
隠岐自然館展示の様子