• Economic and Environmental Geology
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• v.45 no.6
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• pp.709-719
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• 2012

Prospection was performed on the tin mineralized belt in Mwanza and Kongolo areas of Katanga, DR Congo. Most of deposits in Katanga areas are related to the granites which are located in Kibaran belt in NE and SW trends of mid Proterozoic. Metasedimentary rocks in the Kibaran belt are intruded by granites, and tin, niobium and tantalum deposits are especially developed along with tin-granite. Cassiterite, coltan and gold are developed in the pegmatite, quartz vein and greisen in related to the tin-granite in Mwanza and Katanga areas, and they are exploited by artisan in the smale scale. And we conducted the works with the alluviums and stream sediments in the case of no outcrops. With the results of analysis of samples, we will choose a few potential mineralized zones and con-tinue to prosepect precisely.

• Economic and Environmental Geology
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• v.35 no.3
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• pp.179-189
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• 2002

The Geology of the Shizhuyuan W-Sn-Bi-Mo deposits, situated 16 Ian southeast of Chengzhou City, Hunan Province, China, consist of Proterozoic metasedimentary rocks, Devonian carbonate rocks, Jurassic granitic rocks, Cretaceous granite porphyry and ultramafic dykes. The Shizhuyuan polymetallic deposits were associated with medium- to coarse-grained biotite granite of stage I. According to occurrences of ore body, ore minerals and assemblages, they might be classified into three stages such as skarn, greisen and hydrothernlal stages. The skarn is mainly calcic skarn, which develops around the Qianlishan granite, and consists of garnet, pyroxene, vesuvianite, wollastonite, amphibolite, fluorite, epidote, calcite, scheelite, wolframite, bismuthinite, molybdenite, cassiterite, native bismuth, unidetified Bi- Te-S system mineral, magnetite, and hematite. The greisen was related to residual fluid of medium- to coarse-grained biotite granite, and is classified into planar and vein types. It is composed of quartz, feldspar, muscovite, chlorite, tourmaline, topaz, apatite, beryl, scheelite, wolframite, bismuthinite, molybdenite, cassiterite, native bismuth, unknown uranium mineral, unknown REE mineral, pyrite, magnetite, and chalcopyrite with minor hematite. The hydrothermal stage was related to Cretaceous porphyry, and consist of quartz, pyrite and chalcopyrite. Scheelite shows a zonal texture, and higher MoO) content as 9.17% in central part. Wolframite is WO); 71.20 to 77.37 wt.%, FeO; 9.37 to 18.40 wt.%, MnO; 8.17 to 15.31 wt.% and CaO; 0.01 to 4.82 wt.%. FeO contents of cassiterite are 0.49 to 4.75 wt.%, and show higher contents (4.]7 to 4.75 wt.%) in skarn stage (Stage I). Te and Se contents of native bismuth range from 0.00 to 1.06 wt.% and from 0.00 to 0.57 wt.%, respectively. Unidentified Bi-Te-S system mineral is Bi; 78.62 to 80.75 wt.%, Te; 12.26 to 14.76 wt.%, Cu; 0.00 to 0.42 wt.%, S; 5.68 to 6.84 wt.%, Se; 0.44 to 0.78 wt.%.

• Economic and Environmental Geology
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• v.21 no.1
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• pp.57-67
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• 1988

K-Ar age determinations were carried out on muscovite and other gangue and wallrock alteration minerals from seventeen mineral deposits in the Taebaeg mountain district. Tin deposits give the ages of 1792 Ma and 158-127 Ma, whereas tungsten-molybdenum deposits give the ages of 1520-1480 Ma. 173-168 Ma and 84-81 Ma. Polymetallic mineral deposits. gold-silver deposits and sericite deposits yield the ages of 98-52 Ma. 93-75 Ma, and 202 Ma, respectively. Mineralization ages for each genetic type of deposits in this district can be summarized as follows; pegmatite deposits. 1792 Ma ; pegmatite-hydrothermal deposits. 1526-1480 Ma ; greisen deposits. 157-127 Ma ; skarn deposits, 98-73 Ma and 52 Ma ; hydrothermal deposits, 202-168 Ma and 93-76 Ma. Present results together with data available in the literature reveal that five distinct mineralization ages can be recognized in this district ; (1) 1792 Ma, (2) 1526-1480 Ma, (3) 202-127 Ma. (4) 98-73 Ma, (5) 52 Ma, These age data are similar to the reported radiometric age data of igneous rocks in this district except for two ages such as 2154-2084 Ma and 880-738 Ma.

• Economic and Environmental Geology
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• v.44 no.2
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• pp.109-122
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• 2011

The major Mo deposits in South Korea were formed during the Jurassic Daebo orogeny, the Late Cretaceous and the Tertiary post-orogenic igneous activities, and are characterized by a variety of genetic types such as pegmatite, greisen, skarn, porphyry and vein types. The Jangsu mine is a pegmatite-style deposit which is genetically related to the Jurassic ilmenite-series two-mica granite with the Mo mineralization age of $159.6{\pm}4.5$ Ma. The Geumseong mine occurs as a skarn/porphyry-style deposit associated with highly fractionated granite. Its age of Mo mineralization within aplitic cupola is about 96.5~l07.5 Ma. The Yeonil mine is a porphyry-style deposit, and the Geumeum mine is a veinlet-style deposit along the fracture zone with their mineralization ages of $58.4{\pm}1.6$ and $54.4{\pm}1.2$ Ma, respectively. The contrasts in the style of Mo mineralization in Korea reflect the different environment of the related magmatism. The Jurassic mineralization, being related to deep-seated granitoids, occurs as a pegmatite-style deposit, whereas the Cretaceous one, being related to subvolcanic granitoids, occurs as skarn/porphyry/vein-type ore deposits. The Tertiary Mo mineralization has a close relationship with the igneous activities associated with the Tertiary basin formation along the east coast, Korean peninsular.

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

• Proceedings of the KOR-BRONCHOESO Conference
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• 1977.06a
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• pp.9.1-10
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• 1977

Many etiological factors playa significant role in the development of tracheal stenosis; too high tracheostomy (Jackson, 1921), too small stoma (Greisen, 1966), the treatment with respirator using cuffed tube (Pearson et al., 1968; Lindholm, 1966; Bryce, 1972) and infection (Pearson, 1968). Although the incidence has been reduced due to development of surgical technique and antibiotics, the frequency of tracheal stenosis which produces symptoms after tracheostomy ranges from 1.5 per cent (Lindholm, 1967). In the management of the stenosis, mild cases are treated by mechanical dilatation with silicon tube or stent (Schmigelow, 1929; Montgomery, 1965) combined steroid (Birck, 1970), and in the cases of stenosis causes, these removed under the are bronchoscopy. But in severe stenosis, transverse resection with subsequent end-to-end anastomosis has been used in recent years (Pearson et al., 1968). During about 10 years, 1967 to 1977, a total of 23 patients with tracheal stenosis complicated among the 1, 514 tracheostomies have been treated in Severance Hospital. Now, we have obtained following conclusions by means of clinical analysis of 23 cases of tracheal stenosis. 1. The frequency of tracheal stenosis was 23 cases among 1, 514 cases of tracheostomy (1.5%). 2. Under the age of 5, these are 12 cases (52.2 %). 3. The sex incidence was comprised of 18 males and 5 females. 4. The duration of tracheostomy ranges from 4 days to 16 months. 5. The primary diseases requiring tracheostomy were following; central nerve system lesions 11 cases, upper air way obstruction 10 cases, extrinsic respiratory failure 2 cases. 6. Severe wound infections were only 2 cases. 7. The methods of treatment applied to tracheal stenosis were following; closed observation only 5 cases, nasotracheal intubation combined steroid 5 cases, T-tube stent combined steroid 3 cases, fenestration op. 4 cases, revision 4 cases and transverse resection and end-to-end anastomosis 2 cases.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.283-298
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• 2022

In this study, we investigated the mineral geochemistry of the albite-spodumene pegmatite, associated exogreisen, and wall rock from the Boam Li deposit, Wangpiri, Uljin, Gyeongsangbuk-do, South Korea. The paragenesis of the Boam Li deposit consists of two stages; the magmatic and endogreisen stages. In the magmatic stage, pegmatite dikes mainly composed of spodumene, albite, quartz, and K-feldspar intruded into the Janggun limestone formation. In the following endogreisen stage, the secondary fine-grained albite along with muscovite, apatite, beryl, CGM(columbite group mineral), microlite, and cassiterite were precipitated and partly replaced the magmatic stage minerals. Exogreisen composed of tourmaline, quartz, and muscovite develops along the contact between the pegmatite dike and wall rock. The Cs contents of beryl and muscovite and Ta/(Nb+Ta) ratio of CGM are higher in the endogreisen stage than the magmatic stage, suggesting the involvement of the more evolved melts in the greisenization than in the magmatic stage. Florine-rich and Cl-poor apatite infer that the parental magma is likely derived from metasedimentary rock (S-type granite). P₂O₅ contents of albite in the endogreisen stage are below the detection limit of EDS while those of albite in the magmatic stage are 0.28 wt.% on average. The lower P₂O₅ contents of the former albite can be attributed to apatite and microlite precipitation during the endogreisen stage. Calcium introduced from the adjacent Janggun formation may have induced apatite crystallization. The interaction between the pegmatite and Janggun limestone is consistent with the gradual increase in Ca and other divalent cations and decrease in Al from the core to the rim of tourmaline in the exogreisen.