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Geochemical Study of Collision Volcanism at the Plate Boundary in Turkey -Comparison With Subduction Volcanism in Japan-

土耳其板块边界碰撞火山作用的地球化学研究-与日本俯冲火山作用的比较-

基本信息

批准号：
63041085
负责人：
MATSUDA Jun-ichi
金额：
$ 6.4万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Overseas Scientific Survey.
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63041085/
关键词：
Geochemistry Volcano Turkey Collision boundary Sr isotope noble gas He isotope Carbon isotope

项目摘要

All these geochemical data show that there are inhomogeneity in the upper mantle structure related with the plate tectonics in Turkey. In the eastern part, Sr isotopic rations of Karacadag are low, suggesting the less contribution of magma-crust interaction. Sr isotopes for the volcanoes in the lake Van area vary locally. The Sr rations of Nemurut have a correlation with SiO_2 contents, indicating the crustal contamination. He isotopes in this area is higher than that of air, and suggest the presence of mantle He. The value of mantle He is the same as that in the subduction area, suggesting that the He isotopes are the same in both subduction and collision area. In the central part of Turkey, Sr isotopes of Erciyes and Hasan are 0.7038-0.7058 which are in the range of the subduction area. He isotopes show the higher degree of crustal contamination than that in the eastern Turkey. In the western Turkey, the radiogenic ^4He was observed in all over the geothermal area in the Aegean coast. However, the high high ^3He/^4He ratios and low carbon isotopes are obtained in Kula, where Sr isotopes are also very low (0.7030-0.7035). Kula seem to be very special if it is on the extension of Aegean island arc. It should be necessary to examine the Aegean arc in future in comparison with this study.

所有这些地球化学数据表明，与土耳其板块构造有关的上地幔结构存在不均质性。东部卡拉卡达格的锶同位素配分较低，表明岩浆-地壳相互作用的贡献较小。凡湖地区火山的锶同位素在当地有所不同。Nemurut的锶比值与SiO_2含量呈正相关，反映了地壳混染。该区的氦同位素高于空气中的氦同位素，反映了地幔氦的存在。地幔氦的值与俯冲区的值一致，表明俯冲区和碰撞区的氦同位素是相同的。土耳其中部Erciyes和Hasan的锶同位素为0.7038-0.7058，均在俯冲区范围内。氦同位素显示，与土耳其东部相比，地壳污染程度更高。在土耳其西部，爱琴海沿岸地热区的所有地方都观测到了放射性成因的~4He。但库拉具有高的高~3He/~4He比值和低碳同位素，锶同位素也很低(0.7030~0.7035)。如果是在爱琴海岛弧的延伸处，库拉似乎很特别。今后应该有必要对照这项研究来研究爱琴海弧线。