Estimation of time scale for magma intrusion by multiple dykes

多岩脉岩浆侵入的时间尺度估计

基本信息

批准号：
07804032
负责人：
UMINO Susumu
金额：
$ 1.41万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07804032/
关键词：
multiple dyke sheeted dykes dyke intrusion Fudeshima Volcano Troodos Ophiolite Semail Ophiolite magma chmber

项目摘要

Conclusions : Most significant knowledge obtained through the research is as follows ;(1) Multiply chilled-margin dykes(2) Conditions of multiple dyke formation(3) Multiple dykes are common in arc volcanoes and slow spreading ridges, while they may be rare in fast spreading ridges.Multiply chilled-margin dykes : Field research done on Fudeshima Volcano, Izu Oshima, Older volcanics of northern Yatsugatake Volcano and Troodos Ophiolite, Cyprus, revealed the existence of a sort of multiple dykes, which have multiply chilled margins 1-20 cm thick only in several tens of centimeters from the dyke selvages. Such dykes indicate that pulse of magma intrusions repeated in a short time interval.Conditions of multiple dyke formation : In Troodos Ophiolite, Presence of multiple dykes are confined to near the layred gabbros. On the contrary, sheeted dykes occurring in stratigraphically higher horizons are of simple dykes. This suggests the conditions which favor the formation of multiple dykes to be 1) repetition of magma intrusion, and 2) large ratios of frequency of magma intrusion/solidification time of dykes (F/S ratio).Troodos vs. Semail : All sheeted dykes examined in the Semail Ophiolite are simple. This suggests that in Semail, 1) magma did not intrude as pulse, or 2) F/S ratio was very high. In addition to this, generation of magma pulse may be controlled by the ratio of volume of recharged magma/that of magma chamber.

结论：通过这项研究获得的最重要的知识如下：（1）多重冰镇堤坝（2）多个堤防形成的条件（2）多个堤防（3）多个堤防在弧火山中很常见，山脊缓慢散布，而它们在快速传播的山脊中可能很少见。塞浦路斯的Yatsugatake火山和Troodos Ophiolite揭示了存在多种堤坝的存在，这些堤坝仅在距Dyke Selvages的几十厘米中，其厚度为1-20 cm，厚度为1-20 cm。这种堤坝表明，岩浆入侵的脉冲在短时间间隔中重复。相反，在地层上更高的地平线上发生的堤坝是简单的堤坝。这表明有利于形成多种堤坝的条件为1）岩浆入侵的重复，以及2）型堤坝的岩浆入侵/固化时间的频率很大（f/s比）（f/s比）。Troodosvs. Semail：在Semail Ophiolite中检查的所有板染料都很简单。这表明在Semail中，1）岩浆不侵入脉冲，或2）f/s比非常高。除此之外，岩浆脉冲的产生可以由充电岩浆/岩浆腔的体积的比率控制。