• 제목/요약/키워드: volcanic activity

검색결과 188건 처리시간 0.025초

열수변질 함황철석 안산암 기원의 잠재성 특이산성토 물질 (Volcanic Origin Potential Acid Sulfate Soil Material : Hydrothermally Altered Pyrite Rich Andesite)

  • 김재곤;전철민;윤을수;장용선;정필균;정연태
    • 한국토양비료학회지
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    • 제33권5호
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    • pp.311-317
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    • 2000
  • 특이산성토와 잠재성 특이산성토 물질은 전 세계적으로 분포하며, 산성으로 인하여 농업과 환경에서 문제시되어왔다. 대부분이 퇴적기원이며 소수의 경우에 화산기원으로 보고되어왔다. 산성은 잠재성 특이산성토 물질에 함유된 유황광물의 산화과정에서 생성된 황산에 기인한다. 우리나라에서는 보고가 된바 없는 중생대 화산활동에 의하여 생성된 잠재성 특이 산성토 물질을 보고하고저 한다. 봉산통-황철석을 함유하지 않은 안산암질 모재층-황철석을 다량 함유한 안산암의 단면을 야외조사와 화학적 및 광물학적 분석을 통하여 연구하였다. 한때 택지조성과정에 황철석을 함유한 안산암이 지표에 노출되어 황철석의 산화에의한 토양과 지표수의 산성화문제가 제기된 적도 있다. 봉산통과 모재에서는 황철석과 특이산성토의 생성과정에서 나타나는 노란색 반문과 같은 특징들이 나타나지 않았다. 열수변질에 의하여 생성된 안산에 존재하는 황철석이 화산활동에 의한 열수변질 기원임을 지시해주는 육각형 또는 주사위형의 모양과 암석의 갈라진 틈을 따라 산출되는 양상 등을 보여주었다.

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감귤원 토양에서 분리한 인산염 가용화 미생물 Bacillus sphaericus PSB-13의 특성 (Characteristics of Bacillus sphaericus PSB-13 as Phosphate Solublizing Bacterium Isolated from Citrus Orchard Soil)

  • 좌재호;임한철;한승갑;전승종;서장선
    • 한국토양비료학회지
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    • 제40권5호
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    • pp.405-411
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    • 2007
  • 본 연구는 감귤원 토양유형별로 고정되어 있는 난용성 인산염함량을 파악하고 이를 생물학적으로 이용하고자 인산가용화 우수미생물을 선발하여 특성을 조사하였다. 토양중 난용성 인산염의 형태별 분포는 Al-P>Ca-P>Fe-P 순으로 화산회토 토양이 비화산회토 보다 많았다. PDA-P배지를 이용하여 인산염 가용화능이 우수한 Bacillus sphaericus를 분리하였으며 pH 4~5와 $30^{\circ}C$에서 생육이 제일 좋았다. Bacillus sphaericus은 $AlPO_4$에서 324.5 ppm, $Ca_{10}(PO_4)_6(OH)_2$에서 334.8 ppm, $Ca_3(PO_4)_2$에서 207.0 ppm의 유리인산을 생성하였으며 인산효소활성은 $35^{\circ}C$에서 배양할 때 높았다. Bacillus sphaericus를 Bentonite 등 담체에 고정 후 온도를 달리하여 7개월 보존기간 동안 밀도변화를 조사한 결과 $10^5c.f.u.\;g^{-1}$ 수준과 인산가용화능을 유지하여 추후 생물비료로 이용이 가능할 것으로 기대된다.

제주도의 제4기 지구조운동 (Quaternary Tectonic Movement on Cheju Island)

  • 황재하;이병주;송교영
    • 자원환경지질
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    • 제27권2호
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    • pp.209-212
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    • 1994
  • Cheju Island was formed by volcanic activity probably related to the inferred geodynamics in the early Quaternary times. Paleostress analysis, in spite of a few fault slip data collected near Sanbangsan trachyte dome (dated 0.87 Ma) represents an extentional tectonic event with the direction ENE-WSW. Joint anayses in the vicinity of Seahwa reveal three extensional tectonic events of directions NW-SE, NE-SW and ENE-WSW. Especially the extensional event with the direction ENE-WSW affected the whole Cheju area during the most recent time.

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부산시일원(釜山市一圓)(언양(彦陽)-동래지역(東萊地域))의 화성활동(火成活動)과 광화작용(鑛化作用)에 관한 연구(硏究) (Study on the Igneous Activity and Mineralization In the Vicinity of the Tongnae-Eonyang, Pusan)

  • 차문성;김정진;윤현
    • 자원환경지질
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    • 제5권3호
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    • pp.151-160
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    • 1972
  • The region is composed of Cretaceous volcanic and sedimentary rocks; andesites and granites, It is clarified by the writers that most formations ever known as andesites are not igneous origin but hornfelsic sedimentary rocks. Refering to this fact, broad areas in the south-eastern part of the Kyeong-Sang Namdo which are colored as andesites in the geologic maps scale 1/50,000, published by Geological Survey of Korea should be rechecked. In this area, four granite plutons are isolated by the hornfelsic sedimentary formation, andesites and alluvium. Each plutons are zoned by the lithological facies.

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경상분지 중앙부의 구조발달사외 화산활동사 (Aspects of Tectonics and Volcanism Recorded in Cretaceous Medial Kyongsang Basin, SE Korea)

  • 장기홍;박순옥
    • 자원환경지질
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    • 제30권2호
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    • pp.143-151
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    • 1997
  • The history of the Palgongsan Fault comprises the growth-fault, the dormant and the strike-slip phases. Dissecting the Palgongsan Granite, the Palgongsan Strike-slip Fault, which is the product of the final phase, sinistrally offset about 5.5 km as shown in the dislocation of the Hasandong Formation. Faulting, sedimentation and igneous activity were inter-related in the early phases of the Palgongsan Fault. Some other faults such as the Dansan Pond Fault and the Hayang Fault have also been discovered, and their some stratigraphic implications and the ages of faulting are discussed. The anomalous development of the Jindong Formation in the study area and the related stratigraphic problems are discussed. It has been confirmed that the Konchonri Formation deposited over the Chaeyaksan Volcanic Formation in spite of the recent doubts on their such stratigraphic relation. The chronological sequence of the volcanisms of the Kyongsang Basin has been summarized.

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Ulleung-do earthworms - Dagelet Island revisited

  • Blakemore, Robert J.
    • Journal of Species Research
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    • 제2권1호
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    • pp.55-68
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    • 2013
  • Previous surveys on Ulleung-do (Dagelet Isl.) found just ten earthworm taxa while the current survey unearthed a dozen species. Placement of parthenogenetic 'tube' Amynthas dageletensis Hong & Kim, 2005 is resolved as it clearly belongs in synonymy of Metaphire soulensis (Kobayashi, 1938) which becomes a new Ulleung-do record. Other new megascolecids are recorded since Amynthas heteropodus (Goto & Hatai, 1898) and A. baemsagolensis Hong & James, 2001 are confirmed as synonyms of A. corticis (Kinberg, 1867) and A. carnosus (Goto & Hatai, 1899), respectively. The latter taxon is differentiated and its synonym A. pingi (Stephenson, 1925) provisionally revived. New lumbricids are Bimastos parvus (Eisen, 1874), Eisenia japonica (Michaelsen, 1892) and questionably Dendrodrilus rubidus (Savigny, 1826). All confirmed species are common exotics with no endemics. Drawida moniligastrids were not yet located on this remote island for reasons unknown.

한반도 Lineament와 Circular/Arc Structure 연구 (Lineaments and Circular/Arc Structure on the Landsat TM Imagery)

  • 강필종;조민조;이봉주
    • 대한원격탐사학회지
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    • 제7권2호
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    • pp.95-111
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    • 1991
  • The study is to analyze and interpret lineaments and circular/arc structures on the Landsat TM images which cover the Korean peninsula and the attched islands except the Ulneung island. The Landsat TM images which cover the Korean territory are 23 scenes, and band 3 and band 5 were selected for the study from seven bands, because the both vands are sensitive on soil moisture and geological materials. Lineament trend analysis Sinian direction (NNE-SSW), Pyeongan direction(NW-SE), Yodong direction(NE-SW), Korean direction(NNW-SSE) and Danyang direction (WNW-ESE) are predominant lineament trands of Korea. Circular/arc structures can be devided into four categories according to their origin; 1) volcanic activity origin, 2) granite intrusion oringin, 3) structural origin and 4) the others.

통가열도 TA 25 해저산의 열수변질 (Hydrothermal Alteration around the Tofua Arc (TA) 25 Seamounts in Tonga Arc)

  • 조현구;김동호;구효진;엄인권;최헌수
    • 한국광물학회지
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    • 제27권4호
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    • pp.169-181
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    • 2014
  • 우리나라는 2008년부터 심해저 광물자원 확보를 위하여 남서태평양 통가국 EEZ 내 Tofua arc의 해저 화산열도에서 해저열수광상에 관한 조사를 지속적으로 수행하고 있다. 통가국 라우분지 TA 25 해저산에서 해저 열수 활동에 의하여 형성된 광물들의 특성과 분포를 규명하기 위하여 X선회절분석, 주사전자현미경 관찰, X선형광분석과 유도결합 플라즈마 방출분광분석을 실시하였다. 연구에 사용된 시료는 TA 25 해저산 주변에서 채취된 7개의 코어 시료와 9개의 해저퇴적물 시료이다. 열수분출구 모든 지역에서 중정석, 섬아연석, 클리노클레이스 등이 존재하고, 열수분출구 A 지역에는 석고, 스멕타이트 및 카올린 광물, 열수분출구 B와 C 지역에는 스멕타이트, 카올린 광물, 황동석과 황철석, 열수분출구 D 지역에는 석고, 황동석, 황철석, 침철석 등이 분포한다. 점토부분에 대한 분석 결과 칼데라 중심부 지역을 제외한 모든 지역에서 스멕타이트와 소량의 카올리나이트가 포함되어 있는 것으로 보아 이질변질작용에 해당하는 열수변질이 있었음을 알 수 있다. 열수분출구 B, C, D 지역은 여러가지 종류의 황화광물과 비소화광물이 존재한다. 광물조성, 주성분과 미량성분 분석 결과로 판단할 때 열수분출구 B, C, D 지역이 비교적 강한 고온의 열수변질작용, 열수분출구 A와 칼데라 중심부 지역은 열수의 영향을 적게 받았거나 저온의 열수변질작용을 받은 것으로 판단된다. 추후 열수광상 탐사는 열수분출구 B, C, D 지역에서 수행되어야 할 것으로 여겨진다.

한국남부(韓國南部)의 백악기말(白堊紀末) 이후(以後)의 화성활동(火成活動)과 광화작용(鑛化作用)에 대(對)한 판구조론(板構造論)의 적용성(適用性) 연구(硏究)( I ) (Applicability of plate tectonics to the post-late Cretaceous igneous activities and mineralization in the southern part of South Korea( I ))

  • 민경덕;김옥준;윤석규;이대성;주승환
    • 자원환경지질
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    • 제15권3호
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    • pp.123-154
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    • 1982
  • Petrochemical, K-Ar dating, Sand Rb/Sr isotopes, metallogenic zoning, paleomagnetic and geotectonic studies of the Gyongsang basin were carried out to examine applicability of plate tectonics to the post-late Cretaceous igneous activity and metallogeny in the southeastern part of Korean Peninsula. The results obtained are as follows: 1. Bulgugsa granitic rocks range from granite to adamellite, whose Q-Ab-Or triangular diagram indicates that the depth and pressure at which the magma consolidated increase from coast to inland varying from 6 km, 0.5-3.3 kb in the coastal area to 17 km, 0.5-10 kb in the inland area. 2. The volcanic rocks in Gyongsang basin range from andesitic to basaltic rocks, and the basaltic rocks are generally tholeiitic in the coastal area and alkali basalt in the inland area. 3. The volcanic rocks of the area have the initial ratio of Sr^{87}/Sr^{86} varying from 0.706 to 0.707 which suggests a continental origin; the ratio of Rb/Sr changing from 0.079-0.157 in the coastal area to 0.021-0.034 in the inland area suggests that the volcanism is getting younger toward coastal side, which may indicate a retreat in stage of differentiation if they were derived from a same magma. The K_2O/SiO_2 (60%) increases from about 1.0 in the coastal area to about 3.0 in the inland area, which may suggest an increase indepth of the Benioff zone, if existed, toward inland side. 4. The K-Ar ages of volcanic rocks were measured to be 79.4 m.y. near Daegu, and 61.7 m.y. near Busan indicating a southeastward decrease in age. The ages of plutonic rocks also decrease toward the same direction with 73 m.y. near Daegu, and 58 m.y. near Busan, so that the volcanism predated the plutonism by 6 m.y. in the continental interior and 4 m.y. along the coast. Such igneous activities provide a positive evidence for an applicability of plate tectonics to this area. 5. Sulfur isotope analyses of sulfide minerals from 8 mines revealed that these deposits were genetically connected with the spacially associated ingeous rocks showing relatively narrow range of ${\delta}^{34}S$ values (-0.9‰ to +7.5‰ except for +13.3 from Mulgum Mine). A sequence of metallogenic zones from the coast to the inland is delineated to be in the order of Fe-Cu zone, Cu-Pb-Zn zone, and W-Mo zone. A few porphyry type copper deposits are found in the Fe-Cu zone. These two facts enable the sequence to be comparable with that of Andean type in South America. 6. The VGP's of Cretaceous and post Cretaceous rocks from Korea are located near the ones($71^{\circ}N$, $180^{\circ}E$ and $90^{\circ}N$, $110^{\circ}E$) obtained from continents of northern hemisphere. This suggests that the Korean peninsula has been stable tectonically since Cretaceous, belonging to the Eurasian continent. 7. Different polar wandering path between Korean peninsula and Japanese islands delineates that there has been some relative movement between them. 8. The variational feature of declination of NRM toward northwestern inland side from southeastern extremity of Korean peninsula suggests that the age of rocks becomes older toward inland side. 9. The geological structure(mainly faults) and trends of lineaments interpreted from the Landsat imagery reveal that NNE-, NWW- and NEE-trends are predominant in the decreasing order of intensity. 10. The NNE-trending structures were originated by tensional and/or compressional forces, the directions of which were parallel and perpendicular respectively to the subduction boundary of the Kula plate during about 90 m.y. B.P. The NWW-trending structures were originated as shear fractures by the same compressional forces. The NEE-trending structures are considered to be priginated as tension fractures parallel to the subduction boundary of the Kula plate during about 70 m.y. B.P. when Japanese islands had drifted toward southeast leaving the Sea of Japan behind. It was clearly demonstrated by many authors that the drifting of Japanese islands was accompanied with a rotational movement of a clock-wise direction, so that it is inferred that subduction boundary had changed from NNE- to NEE-direction. A number of facts and features mentioned above provide a suite of positive evidences enabling application of plate tectonics to the late Cretaceous-early Tertiary igneous activity and metallogeny in the area. Synthesizing these facts, an arc-trench system of continental margin-type is adopted by reconstructing paleogeographic models for the evolution of Korean peninsula and Japan islands. The models involve an extention mechanism behind the are(proto-Japan), by which proto-Japan as of northeastern continuation of Gyongsang zone has been drifted rotationally toward southeast. The zone of igneous activity has also been migrated from the inland in late-Cretaceous to the peninsula margin and southwestern Japan in Tertiary.

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울릉도와 독도 화산암의 생성연대 및 진화사 (Ages and Evolutions of the Volcanic Rocks from Ulleung-do and Dok-do)

  • 송용선;박맹언;박계헌
    • 암석학회지
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    • 제15권2호
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    • pp.72-80
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    • 2006
  • 동해 한복판에 위치한 울릉도와 독도의 화산암들에 대한 새로운 K-Ar 연대측정으로 독도로부터는 $3.67{\pm}0.40\sim1.89{\pm}0.29Ma$, 그리고 울릉도로부터는 $8.07{\pm}0.39\sim0.51{\pm}0.07Ma$의 결과를 얻었다. 이는 독도와 울릉도 모두 화성활동의 기간이 기존 연구에서 밝혀진 것보다 연장됨을 나타낸다 울릉도의 화산활동 시작은 지금까지 알려졌던 것보다 훨씬 오래전인 $8.07{\pm}0.39Ma$전까지로 확장될 가능성이 있으며, 독도의 최후기 조면암 분출 및 관입은 울릉도의 화성활동 시기로 보고되었던 시기와 중첩되는 $1.89{\pm}0.29Ma$까지 지속되었다. 그러나 울릉도 화산체의 형성은 주로 2.7Ma 이후에 일어났으며, 독도의 화성활동은 이 시기 이전에 대부분 종료된 것으로 보인다. 이는 화산체의 주형성기로 볼 때 독도가 울릉도 이전에 형성되었음을 시사하며, 열점화산활동에 의해 독도 동남부의 해산들로부터 시작하여 독도, 그리고 울릉도로 화산활동이 이어졌다는 해석과 합치한다.