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===Fusaki Formation===
The Fusaki Formation, located at the Ishigaki Island and [[Taketomi Island]] of the Yaeyama Islands in Southern Ryukyu,<ref name=":15" /> comprises weakly metamorphosed [[Olistostrome|olistromal rocks]]: [[allochthon|allochthonous blocks]] of chert, [[mudstone]], sandstone, and limestone are embedded in a muddy [[Matrix (geology)|matrix]].<ref name=":14" /> The metamorphic age of this formation ranges from 145–130 Ma (Early [[Cretaceous]]) and was determined by K-Ar phengitic micas dating.<ref name=":14" /> [[Radiolaria]] data show that the formation accreted in the [[Toarcian]] in the Early Jurassic.<ref name=":6" /> This formation is part of an accretionary complex of a Middle Jurassic subduction zone.<ref name=":14" />
On Ishigaki Island, this formation is thrusted beneath the Tomuru Formation along the Sokobaru [[Thrust fault|thrust]] <ref name=":14" /> and is intruded by [[Oligocene]] granitic rocks, named the Omoto Pluton. <ref name=":6" />
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