• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.77-79
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• 2003

The stability of flows induced by a surface acoustic wave (SAW) propagating along the deformable walls in a confined parallel-plane microchannel or slab in the laminar flow regime is investigated. The governing equation which was derived by considering the nonlinear coupling between the deformable or waving interface and viscous fluids is linearized and then the problem is solved by a verified code based on the spectral method together with the associated interface and boundary conditions. The value of the critical Reynolds number was found to be near 1439 which is much smaller than the rigid-wall case: 5772 for conventional pressure-driven flows.

• The Journal of the Petrological Society of Korea
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• v.25 no.3
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• pp.261-281
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• 2016

Our knowledge of the lithosphere beneath the Korean Peninsula has been improved through petrologic and geochemical studies of upper mantle xenoliths hosted by Quaternary intraplate alkali basalts from Jeju Island. The xenoliths are mostly spinel lherzolites, accompanied by subordinate harzburgite and pyroxenites. The mantle xenoliths represent residual mantle material showing textural and geochemical evidence for at least a three-stage evolution, fractional partial melting, recrystallization, and metasomatism. Their composition primarily controlled by early fractional melt extraction and porphyroclastic and mylonitic fabrics formed in a shear-dominated environment, which was subsequently modified by residual slab-derived fluids (or melts). Modal metasomatic products occur as both anhydrous phase(orthopyroxene) and hydrous phase (phlogopite). Late-stage orthopyroxene is more common than phlogopite. However, chemical equilibrium is evident between the primary and secondary orthopyroxene, implying that the duration of post-metasomatic high temperatures enabled complete resetting/reequilibration of the mineral compositions. The metasomatic enrichment pre-dates the host Jeju Quaternary magmatism, and a genetic relationship with the host magmas is considered unlikely. Following enrichment in the peridotite protolith in the mantle wedge, the upper mantle beneath proto-Jeju Island was transformed from a subarc environment to an intraplate environment. The Jeju peridotites, representing old subarc fragments, were subsequently transported to the surface, incorporated into ascending Quaternary intraplate alkali basalt. The result of this study implies that long term material transfer in the transformation of geotectonic setting from a subarc to intraplate may have played a significant role in the evolution of lithospheric mantle, resulting in the enriched mantle domains, such as EM I or EM II in the lithospheric mantle beneath East Asia.

• Economic and Environmental Geology
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• v.51 no.5
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• pp.439-453
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• 2018

The Eocene Gyeongju granitoids in SE Korea are alkali feldspar granite (AGR), biotite granite (BTGR), and hornblende biotite granodiorite (HBGD) along Yangsan fault and Ulsan fault. According to their geochemical characteristics, these granitoids are classified as A-type (AGR) and I-type (BTGR and HBGD) granitoids, and regarded that were derived from same parental magma in upper mantle. The hornblende and biotite of AGR as an interstitial phase indicate that influx of F-rich fluid during the crystallization of AGR magma. AGR is enriched LILE (except Sr and Ba) and LREE that indicate the influences for subduction released fluids. The highest HFSE contents and zircon saturation temperature of AGR among the Eocene Gyeongju granitoids may indicate that it was affected by partial melting rather than magma fractionation. These characteristics may represent that the high F contents of AGR was affected by F-rich fluid derived from the subducted slab and partial melting. It corresponds with the results of the REE modeling and the dehydrated fluid component (Ba/Th) modeling showing that AGR (A-type) was formed by the partial melting of BTGR (I-type) with the continual influx of F-rich fluid derived from the subducted slab.