Petrology, Geochemistry, and Tectonics of Tertiary Igneous Rocks from the Hidaka Belt, Central Hokkaido

北海道中部日高带第三纪火成岩的岩石学、地球化学和构造

• 批准号: 63540605
• 负责人: MAEDA Jin'ichirou
• 金额: $ 1.09万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63540605/
• 关键词: Hidaka; Hokkaido; NW Pacific; Pankenushi gabbro; Memurodake diorite; Chiroro dolerite; N-MORB; Icelandite; 日高火成活動帯; パンケヌシ斑れい岩体; MORB; カルクアルカリ岩; Sr同位体; Nd同位体; 奥士別岩体; ソレアイト質層状斑れい岩体; 苦鉄質マグマ; 岩石学; 同位体岩石学; 海嶺の沈み込み

Tertiary Hidaka magmatism occurred in a meridional zone extending for about 300 km in Central Hokkaido. The Hidaka magmatism includes tholeiitic layered olivine gabbro, heterogeneous calc-alkaline gabbro-diorite, and I- and S-type granites. Geochemical investigations of the tholeiitic Pankenushi layered gabbroic intrusion, calcalkaline Memurodake heterogeneous pluton, and primitive Chiroro meta-dolerite indicate that they were derived from N-MORB. Therefore Hidaka magmatism is easily explained as normal ridge magmatism intruding into terrigenous sediments. We can assume that the subduction of spreading ridge beneath accretion prism and/or sedimentation of terrigenous sediment on the spreading ridge.We also found icelanditic rocks from the Hidaka belt. They are not similar in major element composition to the differentiated MORB occurred along the spreading ridge but to the tholeiitic andesite occurred on the hotspot along or near spreading ridge, e. g., andesitic rocks from the Galapagos Islands and Iceland.

第三纪日高岩浆活动发生在北海道中部长达300公里的经向带内。Hidaka岩浆作用包括拉斑状层状橄榄辉长岩、非均质钙碱性辉长闪长岩和I型和s型花岗岩。地球化学研究表明，拉斑岩类Pankenushi层状辉长岩侵入体、钙碱性memuroake非均质岩体和原始Chiroro变质玄武岩均来源于N-MORB。因此，Hidaka岩浆活动很容易被解释为侵入陆源沉积物的正常脊状岩浆活动。我们可以假设增生棱柱下扩张脊的俯冲作用和（或）扩张脊上陆源沉积物的沉积作用。我们还发现了来自Hidaka带的冰岛岩石。它们在主元素组成上与沿扩张脊发育的分异MORB不相似，而与沿扩张脊或其附近热点发育的拉斑安山岩相似，如来自加拉帕戈斯群岛和冰岛的安山岩。

项目成果

前田 仁一郎: "北海道中央部の第三紀迸入岩類のKーAr年代と火成活動の時空変遷" 地球科学. 44. 231-244 (1990)

Jinichiro Maeda：“北海道中部第三纪火山岩的 K-Ar 年龄和火成岩活动的时空变化”地球科学 44. 231-244 (1990)。

前田仁一郎,宮坂省吾,池田保夫,末武晋一,戸村誠司,河内晋平,松井愈: "北海道中央部の第三紀迸入岩類のK-Ar年代と火成活動の時空変遷" 地球化学. 44. (1990)

Jinichiro Maeda，Shogo Miyasaka，Yasuo Ikeda，Shinichi Suetake，Seiji Tomura，Shinpei Kawachi，Yu Matsui：“北海道中部第三纪火山岩的K-Ar年龄和火成岩活动的时空变化”地球化学44。（1990）

Maeda, J.: "Origin of the Hidaka magmatic zone, was it old spreading ridge reactivated by subduction of young spreading ridge?" Gekkan Chikyu,. 11. 265-270 (1989)

Maeda, J.：“日高岩浆带的起源，是因为年轻扩张脊的俯冲而重新激活了古老的扩张脊吗？”

前田仁一郎: 月刊「地球」(The Earth Monthly). 11. (1989)

前田仁一郎：《地球月刊》11。（1989）

Maeda, J.: "Chemical features of orthopyroxenes in peralmninous igneous rocks." Am. Mineral.76. (1991)

Maeda, J.：“铁铝质火成岩中斜方辉石的化学特征。”