Presentation Information
[O05-01]How to understand traditions - "Tamoto-ishi" and "Sazare-ishi"★Invited Papers
*Tohru Sakiyama1 (1.Institute of Geo History, Japan Geochronology Network)
Keywords:
calcareous breccia,debris flow,Kimigayo,conglomerate,growing stones
Some regional traditions and forms of folk culture are closely related to geoscientific phenomena and natural disasters. Geomythology examines these relationships. Local traditions may originate in past geological events or reflect historical perceptions of nature. However, uncritical acceptance of such traditions can also generate misinformation and pseudoscience. To illustrate both aspects, this study examines two cases: "Tamoto-ishi" and "Sazare-ishi", both associated with the lyrics of Japan’s national anthem, Kimigayo. The former interprets the lyrics of "Kimigayo" (Japan's national anthem), "Sazareishi no iwa to narite" as "Small stones have grown large," while the latter interprets it as "Small stones have come together to form conglomerate."
In the Arima area at the northern foot of the Rokko Mountains in Hyogo Prefecture, two large rocks—Tamoto-ishi and Butsuza-iwa—are located in a region repeatedly affected by debris flows. Butsuza-iwa is partially buried by 19th-century sediment deposits, and Tamoto-ishi rests above these deposits, suggesting it was transported by a debris flow during or after that period. A local legend states that the goddess of Onsen Shrine threw a small stone from her kimono sleeve, and it gradually grew into Tamoto-ishi. Although stones cannot physically grow in this way, the legend likely emerged in response to the sudden appearance of a large transported boulder. Such narratives reflect contemporary views of nature rather than geological reality.
Rocks known as Sazare-ishi are installed at shrines throughout Japan. Most are calcareous breccias from the Kasuga region of Gifu Prefecture. A tradition claims that the lyrics of Kimigayo refer to limestone breccia from this area, although its historical authenticity remains uncertain (Suzuki, 2003; Kamoi, 2023). Since 1962, local historians inspired by this tradition have donated these stones to shrines nationwide, promoting them as Sazare-ishi. As a result, they have spread widely.
Using photographs of shrine signboards, I examined donation dates and explanatory texts for 175 shrines and related sites. Donation years were confirmed for 95 stones. All 42 examples donated between 1962 and 1999 were calcareous breccia. However, since 2000, 22 of 53 newly identified stones originated from other geological settings, including Triassic conglomerates of the Maizuru Belt, Permian conglomerates of the Southern Kitakami Belt, and Neogene conglomerates associated with Green Tuff activity. In recent years, the term “Sazare-ishi” has increasingly been applied to conglomerates in general. At the same time, explanatory texts containing clear geological errors have increased, and terms such as “spiritual power,” absent from earlier descriptions, now frequently appear.
The formation of calcareous breccia from limestone fragments is a well-established geological process. However, treating legend as literal fact and applying it broadly has generated confusion and misinformation. In contrast, although the growth of pebbles as suggested in the Tamoto-ishi legend is scientifically impossible, it is understandable that such beliefs arose within earlier worldviews.
Regional legends reflect the lived experiences and perceptions of nature held by past communities. Rather than imposing geological explanations directly onto folklore, it is essential to investigate the geological contexts that contributed to their formation. Yanagida (1977) noted that legends of growing stones like Tamoto-ishi were once widespread in Japan and suggested that such consciousness influenced the lyrics of Kimigayo. However, geomythological research on these traditions remains limited, and many examples have already disappeared. Identifying surviving cases and examining their geological background is therefore an urgent task.
References
Kamoi Y. (2023) A geological interpretation of the phrase "Sazareishi no Iwao to narite" from the national anthem "Kimigayo." Earth Science Education and Science Movement, 90, 71-74.
Suzuki H. (2003) The origin of "Sazareishi" (pebbles) and geological considerations. Earth Science, 57, 246-252.
Yanagida K. (1977) Japanese Legends. Shincho Bunko, Tokyo, 185p.
In the Arima area at the northern foot of the Rokko Mountains in Hyogo Prefecture, two large rocks—Tamoto-ishi and Butsuza-iwa—are located in a region repeatedly affected by debris flows. Butsuza-iwa is partially buried by 19th-century sediment deposits, and Tamoto-ishi rests above these deposits, suggesting it was transported by a debris flow during or after that period. A local legend states that the goddess of Onsen Shrine threw a small stone from her kimono sleeve, and it gradually grew into Tamoto-ishi. Although stones cannot physically grow in this way, the legend likely emerged in response to the sudden appearance of a large transported boulder. Such narratives reflect contemporary views of nature rather than geological reality.
Rocks known as Sazare-ishi are installed at shrines throughout Japan. Most are calcareous breccias from the Kasuga region of Gifu Prefecture. A tradition claims that the lyrics of Kimigayo refer to limestone breccia from this area, although its historical authenticity remains uncertain (Suzuki, 2003; Kamoi, 2023). Since 1962, local historians inspired by this tradition have donated these stones to shrines nationwide, promoting them as Sazare-ishi. As a result, they have spread widely.
Using photographs of shrine signboards, I examined donation dates and explanatory texts for 175 shrines and related sites. Donation years were confirmed for 95 stones. All 42 examples donated between 1962 and 1999 were calcareous breccia. However, since 2000, 22 of 53 newly identified stones originated from other geological settings, including Triassic conglomerates of the Maizuru Belt, Permian conglomerates of the Southern Kitakami Belt, and Neogene conglomerates associated with Green Tuff activity. In recent years, the term “Sazare-ishi” has increasingly been applied to conglomerates in general. At the same time, explanatory texts containing clear geological errors have increased, and terms such as “spiritual power,” absent from earlier descriptions, now frequently appear.
The formation of calcareous breccia from limestone fragments is a well-established geological process. However, treating legend as literal fact and applying it broadly has generated confusion and misinformation. In contrast, although the growth of pebbles as suggested in the Tamoto-ishi legend is scientifically impossible, it is understandable that such beliefs arose within earlier worldviews.
Regional legends reflect the lived experiences and perceptions of nature held by past communities. Rather than imposing geological explanations directly onto folklore, it is essential to investigate the geological contexts that contributed to their formation. Yanagida (1977) noted that legends of growing stones like Tamoto-ishi were once widespread in Japan and suggested that such consciousness influenced the lyrics of Kimigayo. However, geomythological research on these traditions remains limited, and many examples have already disappeared. Identifying surviving cases and examining their geological background is therefore an urgent task.
References
Kamoi Y. (2023) A geological interpretation of the phrase "Sazareishi no Iwao to narite" from the national anthem "Kimigayo." Earth Science Education and Science Movement, 90, 71-74.
Suzuki H. (2003) The origin of "Sazareishi" (pebbles) and geological considerations. Earth Science, 57, 246-252.
Yanagida K. (1977) Japanese Legends. Shincho Bunko, Tokyo, 185p.