The Tadamigawa granitic rocks are located at southwestern part of Fukushima prefecture, northeastern Japan. The granite intrudes into Jurassic sedimentary complex of the Ashio terrane. The granites around the Hinoemata village area are divided into two rock types: the Tadamigawa granite and the Hinoematagawa granite. On the field occurrence, the Tadamigawa granite intrudes into the Hinoematagawa granite. In this study, 7 samples of the Hinoematagawa granite and 32 samples of the Tadamigawa granite were analyzed for major, minor and REE compositions by XRF and ICP-MS, respectively. Moreover, we obtained K-Ar biotite ages from both granites, and iron oxidation ratios by titrimetry with potassium permanganate. SiO
2 contents of the Hinoematagawa granite and the Tadamigawa granite range from 59.6 to 69.4 wt% and from 62.5 to 76.1 wt%, respectively. K-Ar biotite ages of the Hinoematagawa granite and the Tadamigawa granite at Taishaku Mountains are 102.3 ± 2.2 Ma and 102.7 ± 2.2 Ma, respectively. However, the Tadamigawa granite at Inagawa area and Tadamigawa area show the ages of 61.7 ± 1.4 Ma and 89.6 ± 1.9 Ma, respectively. The granites are characterized by LREE enrichment, and have relatively constant patterns normalized by CI chondrite. The Hinoematagawa granite shows small negative Eu anomaly (Eu/Eu
* = 0.73-1.01), and the Tadamigawa granite show large Eu anomaly (Eu/Eu
* = 0.26-0.89). The value of Eu anomaly increases with decreasing anorthite content and the Eu anomaly might be concerned with the differentiation of anorthite. The Hinoematagawa granite and the Tadamigawa granite may be generated from the same magma origin. The Hinoematagawa granite shows low Fe
2O
3/FeO ratio (0.28-0.39), however, the Tadamigawa granite shows high Fe
2O
3/FeO ratio (0.24-1.45). The Hinoematagawa granite may be generated from the magma which has low oxygen fugacity. The difference between both granites is concerned with oxygen fugacity variation of source magma.
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