Studies on budget of organic matter in mantle and crust of arc during subduction and magmatism

该项目的目的和目标是，根据EPMA、CNS、FT-JR、Py-GC、Py-GC/MS和天然岩石稳定碳同位素分析，了解弧系俯冲、增生和岩浆作用期间地壳和楔幔挥发性组分的行为和收支，在高压-高温条件下，用天然玻璃+ H_2O +烃进行了实验研究。1）S型花岗岩类中的碳质物质来源于岩浆与周围泥质岩石的相互作用。花岗闪长岩矿物中的颗粒状碳质物质含有长脂族烃键、含氧有机化合物和芳香碎片。这些有机基团的分布在长石、石英和黑云母之间不同。我们的结论是：（a）大部分有机质是在泥质岩石部分熔融过程中从系统中释放出来的，（B）少量有机质被捕获在高粘度的长英质熔体和聚合物中， 关于我们 2）霍罗曼橄榄岩体和高镁安山岩中的橄榄石和辉石中含有含B、N和Cl的碳质物质。从<8-12>霍罗曼橄榄岩体中的尖晶石、斜长二辉橄榄岩和方辉橄榄岩的热解块状岩石中检测到含Cl、N的芳香族化合物、n-C_8烷烃和n-C_4烷烃。在高镁安山岩热解块体中发现了甲苯和萘等芳香族化合物。非<13>碳酸盐碳的δ ^ C值分别为二辉橄榄岩-25.5‰ vs PDB，方辉橄榄岩-23.4‰，纯橄榄岩-21.9‰和-28.0‰。这些结果表明，霍罗曼橄榄岩体和HMA岩浆受到了楔状地幔中流体的影响，流体可能来自俯冲板片。3）初步实验研究了中地壳条件下长英质岩浆及其凝固过程中沉积烃的转化。起始原料和条件为：花岗岩玻璃+烃类[正己烷和正二十四烷] + H_2O ; 5 kb，900℃。结果表明，所有实验产物中均残留有碳质物质，不仅以碳酸盐和石墨的形式存在，而且还以固态烃的形式存在，表明发生了聚合反应。少

The purpose and targets of the project are the understanding of the behavior and budget of volatile components an the crust and wedge mantle during subduction, accretion and magmatism in arc systems based on EPMA, CNS, FT-JR, Py-GC, Py-GC/MS and stable carbon isotopes analyses for natural rocks, and experiments using natural glass + H_2O + hydrocarbon under high P-T conditions.The results of researches are summarized as follows ;1)Carbonaceous matter in S-type granitoids was derived from interaction between granitoid magmas and surrounding pelitic rocks. Particulate carbonaceous materials in minerals in the granodiorite contain long-aliphatic hydrocarbon bonds, oxygen-bearing organic compounds, and aromatic fragments. The distribution of these organic groups differs between feldspar, quartz and biotite. We conclud that (a) most organic matter is released from the system during partial melting of pelitic rocks, however, (b) a small amount is trapped in highly viscous felsic melt and pol … More ymerized during cooling and crystallization of granitoid magma under differing oxidation conditions.2) Carbonaceous matter including B, N and Cl was found in olivine and pyroxene from the Horoman Peridotite Mass and high-Mg andesite. Aromatic compounds with Cl and N, n-C_8 alkane and n-C_<8-12> alkane were detected from pyrolyzed bulk rocks of spinel and plagioclase lherzolite, and harzburgite in the Horoman Peridotite Mass. Aromatic compounds such as toluene and naphthalene were found from pyrolyzed bulk rocks of high-Mg andesite. δ ^<13>C values of non-carbonate carbon are lherzolite : -25.5‰ vs PDB, harzburgite : -23.4‰, and dunite : -21.9‰ and -28.0‰. These results indicate that the Horoman Peridotite Mass and HMA magma were influenced by fluid, which was probably derived from subducted slab, in wedge mantle.3)Preliminary experiments were carried out to examine transformation of sediment -derived hydrocarbons in felsic magma and during its solidification at middle crustal condition. Starting materials and conditions were : granitic glass + hydrocarbon [n-hexane and n-tetracosane] + H_2O ; 5kb, 900℃. Results showed that remnant carbonaceous materials remained in all experimental products, not only as carbonate and graphite but also as solid state hydrocarbon, indicating that polymerization occurred. Less