1994 Fiscal Year Final Research Report Summary
Contamination rate of granitic rocks and metamorphic grade of metamorphic rocks by using ammonium content in biotite
| Project/Area Number |
04640738
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
鉱物学(含岩石・鉱床学)
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| Research Institution | Faculty of Human Development, Kobe University |
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Principal Investigator |
TAINOSHO Yoshiaki Kobe University・Faculty of Human Development Associate Professor, 発達科学部, 助教授 (90030585)
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| Project Period (FY) |
1992 – 1994
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| Keywords | ammonium / granite / metamorphic grade / biotite / contamination / granitization |
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| Research Abstract |
In the metamorphic rocks, ammonium content of biotites from granulite is low compared with those of biotites from hornblende-biotite gneiss. Systematic decreasing tendency of ammonium content was recognized in biotite from amphibolite facies to granulite facies. Ammonium might be liberated from biotite in the granulite and the ammonium content of the biotites would not record the existence of nitrogen in the original rocks.
Ammonium content of biotites in the granitic rocks studied is closely related to the granite type and the occurrence. In the metamorphic origin granitic rocks, the high ammonium content of their biotites is due to to the metamorphic fluid enriched in ammonium. The ammonium content of biotites is very low low in M-type granite, slightly low in I-type granite, somewhat higher in A-type granite and higher in S-type granite.
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