Anthropogenic effect on the formation of Hiroshima Delta -Focusing on historical iron-sand mining in the upper reaches

Sumiko Kubo; Noboru Sadakata; Yasuhiro Kumahara; Yoshiya Iwasa; Akiko Matsumoto

doi:https://doi.org/10.5194/icg2022-345

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ICG2022-345

https://doi.org/10.5194/icg2022-345

10th International Conference on Geomorphology

© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Anthropogenic effect on the formation of Hiroshima Delta -Focusing on historical iron-sand mining in the upper reaches

Sumiko Kubo¹, Noboru Sadakata², Yasuhiro Kumahara³, Yoshiya Iwasa³, and Akiko Matsumoto⁴

Sumiko Kubo et al.

¹Department of Geography, Waseda University, Tokyo, Japan (sumik@waseda.jp)
²Yamaguchi University, Yamaguchi, Japan
³Hiroshima University, Hiroshima, Japan
⁴Weathernews Inc., Chiba, Japan

The Hiroshima Delta is formed at the mouth of Ota River in western Japan. We conducted the grain analyses and radiocarbon dating of uppermost deposit of delta, along with detailed geomorphological mapping. Grain analyses showed that particles in the uppermost part are of granitic origin, while lower part are of accretionary prism origin. Iron slag particles are confirmed in the uppermost part. Radiocarbon ages suggest they deposited after the 15th century. Geomorphological features of the lower Ota River plain show the development of sandy deposits. We concluded that the iron-sand mining and smelting in the upper reach caused rapid growth of the Hiroshima Delta.

How to cite: Kubo, S., Sadakata, N., Kumahara, Y., Iwasa, Y., and Matsumoto, A.: Anthropogenic effect on the formation of Hiroshima Delta -Focusing on historical iron-sand mining in the upper reaches, 10th International Conference on Geomorphology, Coimbra, Portugal, 12–16 Sep 2022, ICG2022-345, https://doi.org/10.5194/icg2022-345, 2022.