Field Trip

On the first day, we will visit the lava plateau of the Tateyama (Midagahara) Volcano and observe the scars of natural disasters. The Tateyama Volcano has been active since ca. 200 ka, and the Shomyo Waterfall, the largest waterfall in Japan, can be found on the lava plateau (ca. 100 ka). Several hundred meters cross-sections of lava can be seen there. We will also see the traces of a large-scale debris flow that accompanied the collapse of a dammed lake caused by an earthquake in 1858.

(a) The Shomyo Falls is the largest waterfall in Japan (460 m). Here, the Shomyo River cuts through the Midagahara lava and the Shomyo Falls lava, flowing from the top of the lava plateau down to the bedrock. (b) Cross-section of the lave plateau. (c) In 1858, a collapse of a dammed lake resulted in a large-scale debris flow that caused loss of life and other severe damage in Toyama Prefecture. This boulder was carried by the debris flow that occurred at that time.
©Tateyama Kurobe Alpine Route, ©Tateyama-Kurobe Geopark

References
・Harayama, S., Takahashi, Y., Nakano, S., Kariya, Y., & Komazawa, M. (2000). Geology of the Tateyama district with Geological Sheet Map at 1:50,000: Geol. Surv. Japan, 218p
・Ito H, & Danišík M. (2020). Dating late Quaternary events by the combined U-Pb LA-ICP-MS and (U-Th)/He dating of zircon: A case study on Omachi Tephra suite (central Japan). Terra Nova, 32, 134–140.  https://doi.org/10.1111/ter.12452
・Nozaki, T. (2015). Historical and pre-historical gigantic landslides in Tateyama Caldera and their mechanism of occurrence. Abstract of 10th Asian Regional Conference of IAEG, 9p. https://www.jseg.or.jp/2015ARC/data/TP1/Tp1-13_1066537_1522870.pdf
・Sato, Y., Kometani, M., Satake, H., Nozaki, T. & Kusakabe, M. (2013). Calcium-sulfate rich water in landslide area of Tateyama Caldera, northern central Japan. Geochemical Journal, 47, 609-623. https://doi.org/10.2343/geochemj.2.0284

On the second day, we will cross the northern part of the Hida range by cable-car and bus. This day will be the highlight of the pre-conference field trip, with topics such as active volcanic activity, glacial erosion, the world's youngest granite and ultra-fast exhumation.
In Mt. Tateyama, we will see the active volcanic activity and glacial landscapes. Then, we will visit the Kurobe Gorge, which was formed by ultra-fast exhumation, and see the outcrops of the world's youngest granite of the Kurobegawa Granite. At these stops, we will discuss the active volcanic activity and tectonics occurring in the northern Hida range.

(a) In Mt. Tateyama, we will see a place where there was volcanic activity, tephra and glacial landscapes. As well as the scenery and outcrops, the strong smell of volcanic gases can also be experienced. (b) The Kurobe Gorge is undergoing ultra-fast exhumation (14.5 mm/yr at max.). Here you can see a large outcrop along the steep valley from the Japan's largest dam. (c) The world's youngest granite of the Kurobegawa Granite is characterized by numerous dark inclusions (mafic magmatic enclaves) like those on a panda.
©Tateyama Kurobe Alpine Route

References
・Bartz, M., King, G. E., Bernard, M., Herman, F., Wen, X., Sueoka, S., ... & Tagami, T. (2024). The impact of climate on relief in the northern Japanese Alps within the past 1 Myr–The case of the Tateyama mountains. Earth and Planetary Science Letters, 644, 118830. https://doi.org/10.1016/j.epsl.2024.118830
・Ito, H., Yamada, R., Tamura, A., Arai, S., Horie, K., & Hokada, T. (2013). Earth's youngest exposed granite and its tectonic implications: the 10–0.8 Ma Kurobegawa Granite. Scientific Reports, 3(1), 1306. https://doi.org/10.1038/srep01306
・King, G. E., Ahadi, F., Sueoka, S., Herman, F., Anderson, L., Gautheron, C., ... & Tagami, T. (2023). Eustatic change modulates exhumation in the Japanese Alps. Geology, 51(2), 131-135. https://doi.org/10.1130/G50599.1
・Yamada, R., & Harayama, S. (1999). Fission track and K-Ar dating on some granitic rocks of the Hida Mountain Range, Central Japan. Geochemical journal, 33(1), 59-66. https://doi.org/10.2343/geochemj.33.59

On the third day, we will visit the Itoigawa Geopark, which is one of the few places where jadeitite (metamorphic rock composed of 80–100 wt% of jadeite) is found. We will see the features of subduction zones, including high-pressure metamorphic rocks and limestone from seamounts. We will also visit the fault outcrop of the Itoigawa-Shizuoka Tectonic Line, which is a major tectonic boundary dividing the western and eastern Japan Arc.

(a) At the “Jadeitite Gorge” on the Kotaki River, you can see a number of jadeitite boulders and a limestone cliff. Here, high-pressure metamorphic rocks and limestone bodies are adjacent to each other, separated by serpentine. (b) Jadeite is designated as a Japan's national stone, and it is a mineral that characterizes Japan not only scientifically but also culturally. (c) The Itoigawa-Shizuoka tectonic line is considered to be part of the boundary between the Amurian Plate and the North American Plate. Permian metabasite and Miocene volcaniclastics are in contact here.
©Itoigawa Geopark Council

References
・Japan’s Rich Culture of Stone, Public Relations office, Government of Japan. https://www.gov-online.go.jp/eng/publicity/book/hlj/html/202110/202110_02_en.html
・Panayotopoulos, Y., Hirata, N., Sato, H., Kato, A., Imanishi, K., Kuwahara, Y., ... & Asano, Y. (2014). Investigating the role of the Itoigawa-Shizuoka tectonic line towards the evolution of the Northern Fossa Magna rift basin. Tectonophysics, 615, 12-26. https://doi.org/10.1016/j.tecto.2013.12.014
・Tsujimori, T., & Harlow, G. E. (2017). Jadeitite (jadeite jade) from Japan: History, characteristics, and perspectives. Journal of Mineralogical and Petrological Sciences, 112(5), 184-196. https://doi.org/10.2465/jmps.170804