15 FEATURE © John Wiley & Sons Ltd, The Geologists’ Association & The Geological Society of London, Geology Today, Vol. 35, No. 1, January–February 2019 Feature Spirits of Yokokurayama: shrine of the Japanese trilobites Christopher Stocker 1 , Mark Williams 1 , Tatsuo Oji 2 , Gengo Tanaka 3 , Toshifumi Komatsu 4 & Simon Wallis 5 1 School of Geography, Geology and the Environment, University of Leicester, Leicester, LE1 7RH, UK cps10@leicester.ac.uk 2 The Nagoya University Museum, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan 3 Institute of Liberal Arts and Science, Kanazawa University, Kakuma-machi, Kanazawa City, Ishikawa 920-1192, Japan 4 Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555, Japan 5 Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan ‘We are such stuff as dreams are made on, and our little life is rounded with a sleep’. So sleep the trilobites of Yokokurayama, a sacred mountain hidden within the beautiful landscape of Japan’s Shikoku’s island. And though Prospero may have been speaking to his daughter and her fiancé (in William Shakespeare’s The Tempest), he might well have been contemplating the magnificent trilobite fossils of Yokokurayama. Japan may be better known for its sweeping volcanic landscapes, majestic castles, Shinto shrines and bullet trains, but it is also home to important collections of Silurian and Devonian trilobites. You will linger a while at ‘ground zero’ in Hiroshima with some sadness, but your heart will be lifted by the chatter of myriad Japanese school children flocking around the ruined Prefectural Industrial Promotion Hall (Fig. 1, above left), the dome of which, now shattered, is an iconic symbol of the blast on 6 August 1945. Your embarkation point will be Hiroshima in SW Honshu Island, for the short journey across the Seto Inland Sea to Matsuyama, our entry port to Shikoku Island. After bidding farewell to Hiroshima, our last view of Honshu is the port at Kure, home to much of Japan’s impressive navy, and as a dozen or more large frigates, destroyers and aircraft carriers float by, we pass gently into the narrow seaway that sweeps between Honshu and Shikoku islands, for a journey of some two hours. Small boats and catamarans pass by us on our way, and small islands too. And one can lose oneself on a journey of adventure across an East Asian sea imagined by some early European visitor to these islands in the seventeenth century. Magnificent Shikoku then unfolds before us. It is an island of contrasts. Its great coastal cities of Kochi and Matsuyama are ultra-modern icons of Japan’s advanced civilization, whilst typically for a Japanese city they retain some old-world castle charm (Fig. 2). In a country with over 120 million inhabitants, Shikoku is the least populated of all of Japan’s major islands, with only about four million people. Its mountainous southern part is remote. Strikingly too, for a Japanese island bisected by high mountains, Shikoku has no active volcanoes. Fortuitously it also lies beyond the ‘teeth’ of Japan’s ‘Median Tectonic Line’. If Shikoku is relatively impoverished in people— at least from a Japanese perspective—it makes up for this in its famous island pilgrimage: a visit to so many shrines that it might have bankrupted the pilgrims of Chaucer’s Canterbury Tales. A pilgrim’s tale The island’s name, Shikoku literally means ‘four provinces’, which date back to the seventh or eighth Fig. 1. The ruined Prefectural Industrial Promotion Hall in Hiroshima. (Photo courtesy of David Siveter.)