TrekGEO > Mineral Trail > Kanto region > Tochigi pref. > Kanuma

Japanese page


Shimo-Ishikawa, Kanuma city, Tochigi pref., Japan


Sediments subjected to diagenesis

Weathered pumice of the Late Pleistocene (32 ka) Akagi-Kanuma tephra (Ag-KP) in the Takaragi Loam Member of the Kanto Loam Foramtion. The Akagi-Kanuma tephra was erupted from the northern crater at the summit of Mount Akagi, and is approximately 1 meter thick. The Akagi-Kanuma tephra underlies the 1 m thick reddish-brown Takaragi Loam Bed. The Akagi-Kanuma tephra distributes widely at the eastern side of Mount Akagi to the Pacific ocean, and its unique oragne color is a good key bed.


Outcrop of a pumice bed of the Akagi-Kanuma tephra (Ag-KP). The pumice bed is composed of less than orange pumice. Note that wet pumices are orange but dry ones turn pale brown. This altered pumice, Kanuma-tsuchi, has been mined and sold as cultivation soil for Bonsai.

Reported Minerals

Mineral Assemblages

  • Imogolite - Allophane
Copyright (c) 2015 NariNari, All Rights Reserved.