• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2005년도 추계학술대회 초록집
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• pp.85-85
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• 2005

• 자원환경지질
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• 제28권6호
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• pp.541-551
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• 1995

The Yeongdeog gold-silver deposits at Jipum, Gyeongsangbugdo, is of a middle Paleogene $(45.52{\pm}1.02Ma)$ vein type, and is hosted in shale and sandstone of Cretaceous age. Based on mineral paragenesis, vein structure and mineral assemblages, the ore mineralization can be divided into two distinct depositional stages. The early stage is associated with base-metals such as pyrite, arsenopyrite (27.99~30.99 at%), hematite, rutile, pyrrhotite, sphalerite (10.53~18.42 FeS mole%), chalcopyrite and galena with wallrock alteration such as chlorite, sericite and pyrite. The late stage is characterized by the Au-Ag mineralization such as electrum, Ag-bearing tetrahedrite, freibergite, pyrargyrite, unidentified mineral, pyrite, sphalerite (1.08~5.57 FeS mole%), chalcopyrite and galena. Fluid inclusion data indicate that fluid temperatures and salinities range from 343 to $227^{\circ}C$ and from 8.3 to 5.7 wt% eq. NaCl in early stage, respectively. Temperatures and salinities of NaCl eq. wt% range from 299 to $225^{\circ}C$ and from 12.9 to 4.3 in late stage, respectively. They suggest that complex cooling histories were occured by the mixing of the fluids. Sulfur fugacity $(-logfs_2)$ deduced by mineral assemblages and composition ranges from 8.3 to 14.7 atm. in early stage, and from 8.8 to 14.5 atm. in late stage. It suggests that the mineralization was related to decrease of temperature in early stage and fluctuations of $fS_2$ with decrease of temperature in late stage. Sulfur and oxygen isotope compositions are 4.48~5.60‰ and 9.25~10.8% in early stage, and late stage is 4.84~7.00‰ and 5.7‰, respectively. It indicated that hydrothermal fluids may be magmatic origin with some degree of mixing of another water during paragenetic time.

• 한국어류학회지
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• 제27권2호
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• pp.104-115
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• 2015

2010년 9월부터 2011년 8월까지 매월 소조기에 낙동강 하구역의 안쪽과 바깥쪽 두 개 정점에서 자치어를 채집하여 종조성의 시공간 분포를 밝혔다. 연구기간 동안 출현한 자치어는 총 7목 26과에 속하는 43개 분류군이 출현하였으며, 망둑어과 자치어가 전체 개체수의 63.1%를 차지하여 가장 우점하였다. 그중 하계 출현 망둑어과 자치어가 개체수비 55.5%로 가장 많이 채집되었다. 그 다음으로 청어 (13.2%), 멸치 (13.0%), 그리고 춘계 출현 망둑어과 자치어 (4.6%), 전어 (3.8%), 동계 출현 망둑어과 자치어 (3.1%), 정어리 (1.2%), 웅어 (0.7%) 순으로 채집되었고, 이들 8개 분류군이 전체 자치어 출현량의 95.0%를 차지하였다. 본 연구에서 출현한 자치어 군집은 총 5개의 그룹으로 구분되었으며, 시기적으로 봄, 여름 및 가을, 그리고 겨울 그룹으로 분리되었다. 특히 여름 및 가을에 자치어 군집의 공간적 분리가 나타났다. 하구역의 안쪽 정점에서는 하계 출현 망둑어과 자치어가 우점하였으며, 바깥 정점에서는 망둑어류 외에 멸치가 우점하였고, 기타 다양한 해수어종의 자치어가 출현하였다.

• 자원환경지질
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• 제26권3호
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• pp.289-309
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• 1993

Milyang pyrophyllite deposit which was formed by hydrothermal alteration occurs in Late Cretaceous andesitic tuff in the Milyang area, Gyeongsangnamdo. The wall rock alteration and genesis of the Milyang pyrophyllite deposit were studied. The ore minerals are composed dominantly of pyrophyllite accompanied by small amounts of quartz, kaolinite, pyrite, dumortierite and diaspore. The alteration halo of this deposit can be divided into three zones on the basis of mineral assemblage; pyrophyllite, sericite and chlorite zone. The common mineral assemblages of each alteration zone are as follows: (1) pyrophyllite zone; pyrophyllite-quartz-kaolinite-pyrite-dumortierite-diaspore, (2) sericite zone; sericite-quartz-pyrite-kaolinite, and (3) chlorite zone; chlorite-plagioclase-quartz. Major element chemistry shows that characteristic depletion in MgO, CaO, and $Na_2O$ and relative increase in FeO from less altered chlorite zone to extensively altered pyrophyllite zone corresponding to variation in mineral assemblages. The paragenesis of ore minerals, oxygen isotope data, chlorite and illite geothermometry suggest that ore deposit was formed at about $250{\sim}330^{\circ}C$. Both hydrogen and silica activities are high in pyrophyllite zone. Potassium activity increases in sericite zone while hydrogen activity becomes low in chlorite zone. The pyrophyllite zone was formed relatively higher temperature than those of sericite and chlorite zones. The ore fluid was considered to be magmatic water in origin derived from the residual granitic magma which interacted with meteoric water.

• 자원환경지질
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• 제29권2호
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• pp.139-150
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• 1996

The Yucheon Bi deposits at Cheongha, Gyeongsangbugdo, is of a middle Paleogene (49 Ma) vein type, and is hosted in sandstone and shale of Banyawal formation in Cretaceous age. Based on mineral paragenesis, vein structure and mineral assemblages, two minera1ization stages were distinguished. The stage I consists of quartz with small amount of chlorite, pyrite, epidote, hal1oysite, vermiculite, serpentine and rutile associated with sericitization. The stage II is characterized by Bi minera1ization such as bismuthinite, Bi-Cu-Pb-S mineral, tetradymite, native gold, pyrite, pyrrhotite, arsenopyrite, wolframite, rutile, hematite, sphalerite, chalcopyrite, galena with alteration of sericite, chlorite, K-feldspar, albite and epidote. Fluid inclusion data indicate that fluid temperature and NaCl equivalent wt.% salinity range from 431 to $150^{\circ}C$ and from 19.2 to 0.18wt.% in the stage II. Evidence of boiling during the base-metal minera1ization indicates pressures 241 to 260 bars. Sulfur fugacity($-log\;f_{S2}$) deduced by mineral assemblages and compositions ranges from 5.1 to 5.7atm in early stage, from > 8.4 atm in middle stage and from 13.5 to 19.3 atm in late stage. It suggests that complex histories of progressive coo1ing, dilution and boiling were occurred by the mixing of the fluids. The ${\delta}^{34}S$, ${\delta}^{18}O$ and ${\delta}D$ data range from 2.5 to 3.9%, -0.5 to -4.1% and -29.7 to -47%, respectively. It indicated that hydrothermal fluids may be magmatic origin with boiling and mixing of meteoric water increasing paragenetic time.

• Ocean and Polar Research
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• 제36권4호
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• pp.437-445
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• 2014

A time-series sediment trap was operated at a water depth of 4950 m from July 2003 to May 2004 at KOMO station ($10^{\circ}30^{\prime}N$, $131^{\circ}20^{\prime}W$) in the northeastern equatorial Pacific, with the aim of understanding the temporal variation of planktonic foraminifera assemblages in response to the seasonal shift of Inter-Tropical Convergence Zone (ITCZ). A total of 22130 planktonic foraminifera specimens belonging to 30 species and 11 genera were identified, which shows a distinct seasonal variation with high values (125~288 specimens $m^{-2}day^{-1}$) in the winter to spring (December-May) and low values (16~23 specimens $m^{-2}day^{-1}$) in the fall (September-November). In addition, seasonal ecological differences of foraminifera assemblages are distinctly recognizable: omnivorous foraminifera occurred predominantly during the summer season, whereas herbivorous ones were dominant during the winter season. Such seasonal variations correspond to the seasonal shift of the ITCZ. Enhanced occurrence of herbivorous species during the winter-spring season seems a result of surface water mixing generated by the southward shift of the ITCZ. The increase in omnivorous species during the summer season may be due to the northward movement of the ITCZ caused by weakened wind speed, resulting in the intensification of water column stratification and nutrient-poor environment. A significant reduction of planktonic foraminifera specimens during the fall is attributed to heavy precipitation and reduction in light intensity.

• 수산해양교육연구
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• 제25권6호
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• pp.1336-1347
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• 2013

The marine algal flora assemblages settled on the artificial seaweed reefs in Jeju-do before and after rocky cleaning were investigated during summer and the early succession of seaweeds attached to the test panels on the structures of the artificial reef after rocky cleaning were observed by visual observations and under the dissecting microscope in order to evaluate the effects of this rocky cleaning operation. Species composition and algal biomass on the Bboolsamgak-typed seaweed artificial reefs before and after rocky cleaning were measured and compared before and after rocky cleaning. Before rocky cleaning in July 2012, only nine algal species had existed on the Bboolsamgak-typed seaweed artificial reefs, however, twenty algal species occurred on the seaweed artificial reefs after rocky cleaning in July 2013. Particularly, 15 species among them in July 2013 were not found in July 2012 and they seemed to occur newly on the artificial reefs. A large quantity of algal biomass increased in July 2013 after rocky cleaning. Based on the importance value, there was a drastic change in the dominant species between July 2012 and July 2013 after rocky cleaning. By dissecting micrographs, an epiphytic diatom, Licmophora sp. and flagellates, were observed on the 9th day. A chlorophyte, Ulothrix flacca was observed after 14 days, Ulva pertusa, Bryopsis pulmosa, crustose coralline algae, and Cladophora spp. were after one month. After two months, a significant species succession was observed from three previous chlorophyte species to crustose coralline algae existed as a dominant species on the panels. In this study, however, any brown algae were not found until three months in the early seaweed succession. All above results indicates that the rocky cleaning is a very efficient method for the establishment of macroalgal assemblages on the artificial reefs.

• 한국어류학회지
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• 제23권1호
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• pp.37-45
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• 2011

진해만 남서부에 출현하는 자치어 종조성의 계절변동을 연구하기 위하여 2009년 1월에서 12월까지 매월 RN80 네트을 이용하여 시료를 채집하였다. 조사 기간 동안 24과 46종의 자치어가 채집되었다. 우점종은 청어(Clupea pallasii), 쥐노래미(Hexagrammos otakii), 전어(Konosirus punctatus), 멸치(Engraulis japonicus), 청베도라치(Parablennius yatabei), 앞동갈베도라치(Omobranchus elegans) 순으로 많이 채집되었는데 이들 6종은 전체 채집개체수의 92.7%를 차지하였다. 어종수, 채집 개체수, 종다양도지수는 뚜렷한 계절 변동을 나타내었다. 종수와 개체수는 각각 7월과 1월에 가장 높은 값을 나타내었다. 주성분분석(PCA)와 상관분석은 군집구조와 우점종들의 출현량이 수온과 유의한 관계가 있음을 보여주었다. 특히, 청어, 쥐노래미, 멸치, 청베도라치의 출현량은 수온과 유의한 관련성이 있었다.

• Journal of Ecology and Environment
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• 제38권2호
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• pp.133-143
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• 2015

Freshwater macrophytes improve the structural heterogeneity of microhabitats in water, often providing an important habitat for zooplankton. Some studies have focused on the overall influence of macrophytes on zooplankton, but the effects of macrophyte in relation to different habitat characteristics of zooplankton (e.g., epiphytic and pelagic) have not been intensively studied. We hypothesized that different habitat structures (i.e., macrophyte habitat) would strongly affect zooplankton distribution. We investigated zooplankton density and diversity, macrophyte characteristics (dry weight and species number), and environmental parameters in 40 shallow wetlands in South Korea. Patterns in the data were analyzed using a self-organizing map (SOM), which extracts information through competitive and adaptive properties. A total of 20 variables (11 environmental parameters and 9 zooplankton groups) were patterned onto the SOM. Based on a U-matrix, 3 clusters were identified from the model. Zooplankton assemblages were positively related to macrophyte characteristics (i.e., dry weight and species number). In particular, epiphytic species (i.e., epiphytic rotifers and cladocerans) exhibited a clear relationship with macrophyte characteristics, while large biomass and greater numbers of macrophyte species supported high zooplankton assemblages. Consequently, habitat heterogeneity in the macrophyte bed was recognized as an important factor to determine zooplankton distribution, particularly in epiphytic species. The results indicate that macrophytes are critical for heterogeneity in lentic freshwater ecosystems, and the inclusion of diverse plant species in wetland construction or restoration schemes is expected to generate ecologically healthy food webs.

• 자원환경지질
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• 제24권1호
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• pp.9-20
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• 1991

구시납석광상은 전남 해남지역의 중생대 백악기 화산암류를 모암으로 산출된다. 모암을 이루는 화산암류는 대부분 웅회암류이나 일부 유문암의 변질산물도 있으며, 이들의 열수변질 산물로서 구시광상의 납석 및 도석을 형성 시켰다. 이 변질작용의 결과로 형성된 광물조합에 의하여 이들은 변질대의 중심부로부터 외각으로 가면서 납석, 디카이트, 석영 및 일라이트-스멕타이트대로 구분된다. 이러한 변질광물의 분포양상은 모암인 장구리응회암이 상대적으로 높은 Si와 K이온 활동도를 갖는 강한 산성 열수용액에 의한 변질작용에 의하여 형성되었음을 지시한다. 이들 광물의 안정영역을 고려할 때 일라이트-스멕타이트대는 $200^{\circ}C$ 이하에서, 디카이트대는 $200{\sim}250^{\circ}C$ 범위에서, 납석대는 $260^{\circ}C$ 이상의 온도 영역에서 형성 되었음을 지시한다. 납석대의 일부에서 다이아스포어를 함유하는 것으로 보아 이때의 최고 온도는 $300^{\circ}C$ 정도에 이르렀을 것이다. 이들 변질작용은 본역에 분포된 화산암류를 형성시킨 화산활동에 기인된 열수변질작용으로 해석된다.