Ami Yoshida Junko Shikimori Takeshi Ohno Yuta Ijichi Yusuke Fukami Masahiro Sakata Takafumi Hirata
Journal of environmental radioactivity 255 107011-107011 2022年9月 [査読有り]
We examine the historical changes of 236U/238U and 235U/238U in a sediment core collected in Tokyo Bay and elucidate the anthropogenic sources of uranium in the 1960s-2000s. Uranium-236 was detected in samples deposited in the 1960s-2000s, and the...
Geochimica et Cosmochimica Acta 318 279-291 2022年2月 [査読有り]
We present the first report of the concentrations and stable isotope compositions of Te in the surface layer of ferromanganese crusts collected from the slope of two seamounts in the Northwest Pacific Ocean, Takuyo-Daigo and Takuyo-Daisan, which c...
Takeshi Ohno Naoki Sato Junko Shikimori Yuta Ijichi Yusuke Fukami Yasuhito Igarashi
Science of the Total Environment 2021年 [査読有り]
We examine the temporal changes of 236U/238U and 235U/238U in atmospheric deposition from samples collected in Tokyo and Akita from 1963 to 1979 and elucidate the spatial distribution and historical changes of the anthropogenic sources of uranium ...
Nickel (Ni), copper (Cu), and zinc (Zn) are commonly used in human activities and pollute aquatic environments including rivers and oceans. Recently, Ni, Cu, and Zn isotope ratios have been measured to identify their sources and cycles in environm...
冥王代は生命の誕生した時代であり、冥王代の地球表層環境を知ることは生命の誕生と進化を理解する上で重要である。しかし、冥王代に形成された岩石は見つかっておらず、数少ない物的証拠として注目されているのがジルコンである(Wilde et al., 2001)。近年、アイスランドなどの海洋島で産出するジルコン中のSc/Ybが島弧のジルコンに比べ低いことが報告され(Grimes et al., 2015)、これらの微量元素を用いた指標がジルコンの生成環境に制約を与えることが期待されている。本研究では...
人文科学研究科
理学部