1996 Fiscal Year Final Research Report Summary
Estimation of time scale for magma intrusion by multiple dykes
| Project/Area Number |
07804032
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Petrology/Mineralogy/Science of ore deposit
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| Research Institution | Shizuoka University |
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Principal Investigator |
UMINO Susumu Shizuoka University, Department of Biology & Geosciences, Associate professor, 理学部, 助教授 (30192511)
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| Project Period (FY) |
1995 – 1996
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| Keywords | multiple dyke / sheeted dykes / dyke / intrusion / Fudeshima Volcano / Troodos Ophiolite / Semail Ophiolite / magma chmber |
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| Research Abstract |
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.
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Research Products
(6 results)
