[ Top ] [ Japanese ]

Yumigahama Sandbar

Invalid name: Yumigahama Formation

Marine clay bed at the lower level than Nakaumi Formation

There are opinions that the mud-sands-gravels bed covered with Daikonjima Basalt and Eshima Basalt is not Yumigahama Sandbar.

• Coherent formation
• Holocene
• Uchihama: Holocene (Jomon transgression)
• Nakahama: Holocene (Yayoi era - ca. 900 BC)
• Uchihama: Holocene (ca. 900 BC or later)
• Correlation: Sashimi Formation, Nakaumi Formation

• Sedimentary facies: Marine
• Sedimentary facies: Sand bars, Beach ridges, Interbarnal lowlands
• Lithofacies: Sands, Gravels, Clay

• Thickness: 12 - 17 m
• Upper limit: Unconformity (Daikonjima Basalt?, Eshima Basalt?, Yasugi Formation?)

------ Conformity, ~~~~~~ Unconformity, ~~~--- Local unconformity, '''/,, Interfingered, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown

• Distribution: Yodoe town, Yonago city, Tottori pref.; Daikon island - Eshima island - Moriyama, Yatsuka village, Matsue city, Shimane pref.
• Fossils (Shellfishes): Anadara broughtonii, Anadara granosa, Cerithidea djadjariensis, Dosinia penicillata, Nassarius eivescens, Paphia undulata, Theora lubrica?, Tritia festiva
• Tephra: DMP

• Kano et al. (2025) Geology of the Yonago District (2nd Ed.), Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 84p. (in Japanese with English abstract 4p.)
• Sawada et al. (2009) Jour. Geol. Soc. Japan, vol.115, Supplement, pp.51-70 DOI
• Kano et al. (1998) Geology of the Taisha District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 58p. (in Japanese with English abstract 3p.)
• Kano and Nakano (1985) Geology of the Mihonoseki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 28p. (in Japanese with English abstract 3p.)
• Kano and Yoshida (1985) Geology of the Sakaiminato District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 57p. (in Japanese with English abstract 5p.)