• Proceedings of the KSEEG Conference
• /
• 2001.04a
• /
• pp.209-211
• /
• 2001

• Journal of the Mineralogical Society of Korea
• /
• v.25 no.4
• /
• pp.221-231
• /
• 2012

Uljin cassiterite deposit had been known to be a pegmatitic origin derived from the Wangpiri (Buncheon) granitic gneiss of Precambrian period. Lithium ore also shows the same origin and its lithium bearing mineral was ascertained to be a taeniolite. But the presence of leucocratic granites which played the role of host rocks haven't been clearly designated yet in these provinces. Even though Bonghwa and Youngweol sericite deposits situated in the vicinities of Hambaeg syncline had been known to have their host rocks as Hongjesa Granites of Precambrian period and Pegmatitic migmatite of unknown age respectively. But younger leucocratic granites are characterized by more amounts of albite and sericite (muscovite-3T type) than those of the older granitic rocks which contain plenty of biotite and chlorites. Although the younger granites show rather higher contents of alkalies such as $Na_2O$ (0.13~8.03 wt%) and $K_2O$ (1.71~6.38 wt%), but CaO (0.05~1.21 wt%) is very deficient due to the albitization and greisenization. Manisan granite, which is assumed to be Daebo granite which intruded the Gyunggi Gneiss Complex was again intruded by leucocratic granite whose microclinized part changed into kaolins. Taebaegsan region shows a wide distribution of carbonate rocks which are especially favorable to the ore depositions. And the presence of alkali granites which formed in the later magmatic evolution are well known to be worthwhile to the prospections of various rare metals and REEs resources.

• The Journal of the Petrological Society of Korea
• /
• v.11 no.1
• /
• pp.1-16
• /
• 2002

The study area is mostly composed of Precambrian Gyeonggi gneiss complex, Jurassic Daebo granites, Cretaceous tonalite and dykes, and so on. On the basis of field survey and mineral assemblage, the granites can be divided into three types; biotite granite (Gb), garnet biotite granite (Ggb) and two mica granite (Gtm). They predominantly belong to monzo-granites from the modes. Field relationship and K-Ar mica age data in the surrounding area suggest that intrusive sequences are older in order of Gtm, Ggb and Gb. Gb and Ggb, major study targets, occur as medium-coarse grained rocks, and show light grey and light grey-light pink colors, respectively. Mineral constituents are almost similar except for opaque in Gb and garmet in Ggb. Gb and Ggb have felsic, peraluminous, subalkaline and calc alkaline natures. In Harker diagram, both rocks show moderately negative trends of $TiO_2$, MgO, CaO, $Al_2O_3$, $Fe_2O_3$(t), $K_2O$ and $P_2O_5$ as $SiO_2$ contents increase. Among them, $TiO_2$, MgO and CaO show two linear trends. From the trends and the linear patterns in AFM, Sr-Ba and Rb-Ba-Sr relations, it is likely that they were originated from the same granitic magma and Ggb was differentiated later than Gb. REE concentrations normalized to chondrite value have trends of parallel LREE enrichment and HREE depletion. One data of Ggb showing a gradually enriched HREE trend may be caused by garnet accompaniment. Ggb have more negative Eu anomalies than Gb, suggesting that plagioclase fractionation in Ggb have occurred much stronger than that in Gb. In modal (Qz+Af) vs. Op, Gb and Ggb belong to magnetite-series and ilmenite-series, respectively. From the EPMA results, opaques of Gb are magnetite and ilmenite, and those of Ggb are magnetite-free ilmenite or not observed. Bimodal distribution of magnetic susceptibility reveals two different granites of Gb (332.6 ${mu}SI$) and Ggb (2.3 ${mu}SI$). Based on the paleomagnetic analysis as well as modal analysis, the main susceptibilities of Gb and Ggb reside in magnetite and mafic minerals, respectively. They belong to S-type granite of non-magnetic granite by susceptibility value. In addition, $SiO_2$ contents, $K_2O/Na_2O$, A/CNK molar ratio and ACF diagram support that they all belong to S-type granites.

• The Journal of the Petrological Society of Korea
• /
• v.6 no.3
• /
• pp.166-184
• /
• 1997

The Wondong caldea is a deeply eroded structure that offers spectacular exposures through the core and margins of a resurgent caldera. The Wondong Tuff and the postcollapse intrusions range from medium-silica rhyolite to rhyodacite in composition and the postcollapse lava and tuff, preresurgent and resurgent intrusions also range from medium-silica rhyolite to an-desite, which jump to gap dacite composition. The continuous compositional zonations generally define a large stratified magma system in the postcollapse and resurgent magma chamber. Isotopic and trace element evidence suggest that the compositional zonations might have resulted from the differentiations from crystal fractionations of a parental andesitic magma, accompanying a little contamination from the crustal assimilations near the chamber roof and wall. But chemically and isotopically distinct late intusions might have resulted from emplacement of any different magma batch.

• The Journal of the Petrological Society of Korea
• /
• v.8 no.2
• /
• pp.71-80
• /
• 1999

We report zircon morphology of granitoids in the Mt. Keumjeong district, Pusan. There are a series of granitoids in the study area of the late Cretaceous: granodiorite, hornblende granite, adamellite, tonalite, biotite granite, and micrographic granite. Generally, the shapes of zircon crystals are short prismatic to middle prismatic and are dominant in {loo) prism and {101) pyramid in total average morphological data of the granitoids. The crystal forms of zircon in the granitoids can be distinguished by the PPEF diagram and the prism index (PI). The prism index values of zircon crystal forms in granodoirite and hornblende granite are higher than those of tonalite and micrographic granite. The finishing temperature range ($820~800^{\circ}C$) for crystallization of zircon crystals in granodoirite and hornblende granite is higher than the temperature ($790~770^{\circ}C$) at which the zircon crystals are created in tonalite and micrographic granite. The last differentiates (biotite granite and micrographic granite) have mainly intermediate zircon ({110)={100)) crystals, respectively. As differentiation proceeds, the zircons of granitoids become from short prismatic to middle prismatic in the each granitoid types.

• The Korean Journal of Pharmacology
• /
• v.26 no.2
• /
• pp.193-207
• /
• 1990

Transforming growth factor ${\beta}(TGF-{\beta})$ is a multifunctional polypeptide with diverse effects on the proliferation, differentiation and other functions in many cell types. $TGF-{\beta}$ is highly abundant in bone matrix and induces divergent responses in many aspects of bone cell metabolism . Several lines of investigation indicate that matrix-associated $TGF-{\beta}$ is the products of bone cells themselves. However, exact bone cell type reponsible for the production of $TGF-{\beta}$ is still in controversy, The present study was undertaken to determine the cellular origin of matrix-associated $TGF-{\beta}$ and to assess how different bone cells respond to $TGF-{\beta}$. As a prerequisite for this, 5 bone cell populations of distinct phenotype were isolated from fetal calvaria with sequential enzyme digestion protocol and biochemical characterization. Calvarial cell populations released in early stage showed fibroblastic features whereas populations relesed later was enriched with osteoblast-like cell as judged by their acid and alkaline phosphatase activities, cAMP responsiveness to parathyroid hormone, calcitonin and prostaglandin $E_2$ and collagen synthesis rate. By polyacylamide gel and immunoblot analysis of bone and calvarial cell extracts, presence of $TGF-{\beta}$ in bone tissues and production of $TGF-{\beta}$ by bone cells were confirmed again. Subsequent analysis of calvarial cell extracts prepared as individual population revealed that all calvarial cell populations synthesize $TGF-{\beta}$. Exogenously added $TGF-{\beta}$ induced biphasic response upon bone cell proliferation under serum-free condition. In osteoblastic cell populations, it was stimulatory whereas inhibitory in fibroblastic cell populations. In contrast, collagen and noncollagen protein synthesis of all calvarial cell populations were stimulated by $TGF-{\beta}$. Enhancement of protein synthesis was found to be more general rather than specific for collagen synthesis. In addition, effects of $TGF-{\beta}$ on protein synthesis were independent to its effects on cell proliferation. In summary, production of $TGF-{\beta}$ by bone cells and differential actions on various cell populations observed in this study suggest that $TGF-{\beta}$ may play an important role in the regulation of bone metabolism by modulating the specific cellular functions in autocrine and paracrine fashion.