Development of a new paleopiezometer based on deformation microstructures : application to mantle flow

基于形变微结构的新型古水压计的开发：在地幔流中的应用

• 批准号: 11440149
• 负责人: MICHIBAYASHI Katsuyoshi
• 金额: $ 4.8万
• 依托单位: Shizuoka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11440149/
• 关键词: Structual Geology; Mantle lithosphere; Oman ophiolite; Rheology; オマーンオフィオライト; レオロジー; かんらん岩; 古歪速度計; オフィオライト; マントル; カンラン石; スピネル; 拡散クリープ; 転位クリープ; 変形; オマーン; カンラン岩; 結晶構造; 海洋プレート; アラビア半島; オマーン王国

Structural and fabric analysis of the well-exposed Hilti mantle section, Oman ophiolite, suggests that shear zone development, which may have resulted from oceanic plate fragmentation, was influenced by pre-existing mantle fabric present at the paleo-ridge. Detailed structural mapping in the mantle section revealed a gently undulating structure with an east-west flow direction. A NW-SE strike-slip shear zone cuts across this horizontal structure. The crystal preferred orientation (CPO) of olivine within the foliation is dominated by (010) axial patterns rather than more commonly observed (010) [100] patterns, suggesting that the horizontal flow close to the Moho involved non-coaxial flow. Olivine CPO within the shear zone formed at low temperature is characterized by (001) [100] patterns and a sinistral sense of shear. The structural behavior of oceanic mantle lithosphere during subduction and obduction may be strongly influenced by initial mechanical anisotropy developed at an oceanic spreading center.

结构和面料的分析，以及暴露的希尔蒂地幔部分，阿曼蛇绿岩，表明剪切带的发展，这可能是由于海洋板块的破碎，是受预先存在的地幔结构存在于古脊。地幔部分的详细结构测绘显示出一个东西向流动的平缓起伏结构。一条北西-南东向的走滑剪切带横穿该水平构造。叶理中橄榄石的晶体择优取向（CPO）主要由（010）轴向模式而不是更常见的（010）[100]模式控制，这表明莫霍面附近的水平流动涉及非同轴流动。低温剪切带中的橄榄石CPO具有（001）[100]型和左旋剪切方向的特征。大洋地幔岩石圈在俯冲和仰冲过程中的结构行为可能受到大洋扩张中心形成的初始力学各向异性的强烈影响。

项目成果

Arai, S., Takada, S., Michibayashi, K., Kida, M.: "Petrology of peridotite xenoliths from lraya volcano, Philippines, and implications for mantle wedge processes beneath arcs"Journal of Petrology. (印刷中).

Arai, S.、Takada, S.、Michibayashi, K.、Kida, M.：“菲律宾伊莱亚火山橄榄岩捕虏体的岩石学及其对弧下地幔楔过程的影响”《岩石学杂志》（正在出版）。

Arai, S., Takada, S., Michibayashi, K. & Kida, M.: "Petrology of peridotite xenoliths from Iraya volcano, Philippines, and implications for mantle wedge processes beneath arcs"Journal of Petrology. in press.

荒井 S.、高田 S.、道林 K.

Togami, S., Takano, M., Kumazawa, M. & Michibayashi, K.: "An algotrithm for the transformation of XRF images into mineral-distribution maps"Canadian Mineralogist. 38, part 5. 1283-1294

户上，S.，高野，M.，熊泽，M.

Michibayashi, K., Togami, S., Takano, M., Kumazawa, M. & Kageyama, T.: "Application of the scanning X-ray analytical microscope to the ductile shear zone : an alternative method to image microstructures"Tectonophysics. 310. 55-67

道林，K.，户上，S.，高野，M.，熊泽，M.

Nicolas,A.,Boudier,F.,Michibayashi,K.and Gerbert-Gaillard,L.: "Aswad massif (United Arab Emirates). Archetype of the Oman -UAE ophiolite belt"Geological Society of America Bulletin. (印刷中). (2001)

Nicolas, A.、Boudier, F.、Michibayashi, K. 和 Gerbert-Gaillard, L.：“阿斯瓦德地块（阿拉伯联合酋长国）。阿曼-阿联酋蛇绿岩带的原型”美国地质学会公报（正在出版）。 (2001)