@article{oai:kanazawa-u.repo.nii.ac.jp:00010197,
 author = {森下, 知晃 and 荒井, 章司 and 脇元, 理恵 and 水田, 敏夫 and 石山, 大三 and 佐藤, 比奈子 and 梅香, 賢 and 藤沢, 亜希子 and 盛一, 慎吾 and 大世古, 光弘 and 森, 尚仁 and 山崎, まゆ and 山本, 真也},
 issue = {4},
 journal = {地質学雑誌},
 month = {Apr},
 note = {石川県南部地域に分布する医王山累層流紋岩中の暗色を呈する脈状岩石(暗色珪質脈)の記載岩石学的特徴・地球化学的特徴を明らかにした.暗色珪質脈は流紋岩の破砕帯に沿って,ネットワーク状,プレッチャー状に産し,主に数μm程度の石英と流紋岩起源の破砕片によって構成されている.暗色珪質脈はSiO_2含有量が高く,コンドライト値で規格化した希土類元素のパターンはNdよりも重い元素で暗色珪質脈と流紋岩のパターンは一致し,La,Ceは暗色珪質脈の方が富む.本岩石は,流紋岩の破砕による破砕片の移動とその部分の付加型珪質化作用によって形成されたものであると考えられる.また,変質鉱物の組み合わせにより,破砕に伴う暗色珪質脈形成の後に,100℃以下の低温変質作用を露頭全体が被ったといえる. Anastomosing networks of massive dark-colored veins (Dark-colored silica veins hereafter) ranging from a few millimeters to 8cm in thickness occur in a fault zone of Tertiary rhyolites (the Iozen formation) from the southern Ishikawa Prefecture, Japan. Optical microscopic observations combined with SEM and XRD studies revealed that the Dark-colored silica veins mainly consist of very fine-grained quartz (10μm in size) with minor amounts of feldspar and Fe-bearing unidentified phase. Angular to subangular lithic clasts derived from the host rhyolite are frequently embedded in fine-grained quartz matrix of the Dark-colored silica veins. The Dark-colored silica veins are apparently abundant in SiO_2 relative to the host rocks. Chondrite-normalized rare earth element (REE) pattern of a Dark-colored silica vein is similar to that of the host rhyolite for middle to heavy REE, whereas light REE (La and Ce) concentrations are higher in the Dark-colored silica vein than in the host rhyolite, resulting in high La/Yb ratio in the Dark-colored silica vein. The Dark-colored silica veins might be originated by extreme crushing of the host rhyolite in fault zones followed by the selective enrichment of SiO_2 (+ LREE) coupled with diluting of other elements. The outcrop including the Dark-colored silica vein was finally suffered from low-temperature alternation (<100℃), leading to form clay minerals, particularly along the fault zone., 金沢大学大学院自然科学研究科},
 pages = {273--283},
 title = {石川県南部地域の第三紀流紋岩(医王山累層)中に産する暗色珪質脈の岩石学的特徴},
 volume = {112},
 year = {2006}
}