• Title/Summary/Keyword: 중생대 백악기

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한국 경북 고령지역에서 발견된 중생대 백악기 담수어류화석 Wakinoichthys sp.

  • Kim, Tae-Wan;Yang, Seung-Yeong
    • 한국지구과학회:학술대회논문집
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    • 2005.02a
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    • pp.126-134
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    • 2005
  • 최근 중생대 전기 백악기(약 1.2Ma) 지층이 분포하는 경북 고령의 지역에서 대량으로 발견된 골설목(骨舌目, Osteoglosomorpha) 어류화석을 기재하고 특징을 살펴본 후 현생골설목과의 관계를 조사하고, 아울러 다른 나라에서 발견된 것과의 비교연구를 통해 우리나라에서 발견된 어류화석의 고생물학적 의의를 살펴보았다. 경상층군에서 발견된 어류 화석군은 Semionotiformes, Amiiformes목, 골설목, 당멸치목(Elopiformes), 여을멸목(Albuliformes), Ichthyodectiformes목 등으로 구성되어 있으며, 그중 골설목(Osteoglossiformes)과 여을멸목(Albuliformes)이 가장 풍부하다. 경상어류화석군은 한국의 중생대 백악기 지층에서는 유일한 어류화석군이다. 또한 어류화석과 함께 발견된 여러 화석 및 지질학적 자료를 토대로 어류화석 서식 당시의 고환경을 유추하였다.

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대구분지 북부 팔공산 지역의 지질에 따른 지형발달의 특성

  • 조우영;윤순옥;황상일
    • Proceedings of the KGS Conference
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    • 2002.11a
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    • pp.97-100
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    • 2002
  • 지표의 기복은 암석의 차별적 풍화와 침식을 반영하므로, 기복의 형성에서 암석이 차지하는 몫을 이해하는 것은 중요하며 이 문제는 근대지형학의 발달 초기부터 중요하게 다루어져 왔다(권혁재, 2002).(Picture Omitted) 대구분지 북쪽 분수계를 이루고 있는 팔공산의 기반암은 중생대 백악기 말부터 제 3기초기에 걸쳐 백악기 퇴적암인 경상누층군을 관입하여 형성된 불국사화강암이다.(중략)

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Sauropod Tracks and Trackways from the Cretaceous Kyokpori Formation, Buangun, Jeollabukdo (전라북도 부안군 백악기 격포리층에서 산출된 용각류 발자국 화석과 보행열)

  • Kim, Kyung Soo;Kim, Jeong Yul;Kong, Dal Yong
    • Korean Journal of Heritage: History & Science
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    • v.42 no.1
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    • pp.4-19
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    • 2009
  • Total 57 sauropod tracks are found from the Cretaceous Kyokpori Formation in the Buangun, Jeollabukdo, Korea. Six sauropod trackways in second stratigraphic level of three stratigraphic levels were recognized and described. The type of sauropod trackways is a wide-gauge trackway which has been generally in Cretaceous sauropod trackways. On the basis of foot length, trackway orientations, and preservation, all of the tracks are thought to have been made by small sauropods moving not only towards and away from the shoreline but also along the shoreline of lacustrine environment.

Preservation and Practical Application of Stromatolites in Gyeong-San (경산 스트로마톨라이트의 보존과 활용방안)

  • Han, Seung Hee
    • Journal of the Korean association of regional geographers
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    • v.23 no.2
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    • pp.366-375
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    • 2017
  • Researching Stromatolites spread all over Gyeong-San, province Gyeongsangbukdo, it raise an objection for preservation of original state caused by natural weathering, artificial destruction, illegal emission and enviromental pollution. Stromatolites in Gyeong-San was formed on lake Meszoic era cretaceous. So it is representative rock of geological feature of sediment formed in water and landscape. It could be used as educational data on mesozoic stratum and earth surface, and resources of observation and experience program. It could apply as educational venue place in terms of Mesozoic era cretaceous motif. And it is managed various programs appling 4H (Healing, Hiking, Hand, History) experience program based on local community. And it is concerned software program introducing augumented reality, furthermore discuss with related field.

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Mesozoic Gold-Silver Mineralization in South Korea: Metallogenic Provinces Reestimated to the Geodynamic Setting (남한의 중생대 금-은광화작용: 지구동력학적 관점에서 재검토된 금-은광상구)

  • Choi, Seon-Gyu;Park, Sang-Joon;Kim, Sung-Won;Kim, Chang-Seong;Oh, Chang-Whan
    • Economic and Environmental Geology
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    • v.39 no.5 s.180
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    • pp.567-581
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    • 2006
  • The Au-Ag lode deposits in South Korea are closely associated with the Mesozoic granitoids. Namely, the Jurassic deposits formed in mesozonal environments related to deep-seated granitoids, whereas the Cretaceous ones were developed in porphyry-related environments related to subvolcanic granitoids. The time-space relationships of the Au-Ag lode deposits in South Korea are closely related to the changing plate motions during the Mesozoic. Most of the Jurassic auriferous deposits (about $165{\sim}145$ Ma) show fluid characteristics typical of an orogenic-type gold deposits, and were probably generated in a compressional to transpressional regime caused by an orthogonal to oblique convergence of the Izanagi Plate into the East Asian continental margin. On the other hand, strike-slip faults and caldera-related fractures together with subvolcanic activity are associated with major strike-slip faults reactivated by a northward (oblique) to northwestward (orthogonal) convergence, and probably have played an important role in the formation of the Cretaceous Au-Ag lode deposits (about $110{\sim}45$ Ma) under a continental arc setting. The temporal and spatial distinctions between the two typical Mesozoic deposit styles in South Korea probably reflect a different thermal episodes (i.e., late orogenic and post-orogenic) and ore-forming fluids related to different depths of emplacement of magma due to regional changes in tectonic environment.

지질과학의 세계 - 공사장서 찾은 곤충화석

  • Jang, Sun-Geun
    • The Science & Technology
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    • v.33 no.11 s.378
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    • pp.13-13
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    • 2000
  • 남해고속도로 진주 인터체인지 근처의 공사장에서 중생대 백악기 곤충화석을 발견해 이를 중심으로 연구한 두 고교선생님이 과학전람회에서 대통령상을 받았다. 곤충은 4억2천만년 전에 진화에 지금도 지구상에 1백20만종 이상이 살고있는데, 이번 발견한 화석은 아주 완벽한 것으로 날개의 가느다란 시맥이 그대로 보존돼 세계적으로 관심을 모으고 있다.

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Geochronology and Cooling history of the Mesozoic Granite Plutons in the Central Part of the Ogcheon Fold Belt, South Korea (남한 습곡대 중앙부의 중생대 화강암 질암의 생선년대와 냉각사)

  • Myung-Shik JIN
    • The Journal of the Petrological Society of Korea
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    • v.4 no.2
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    • pp.153-167
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    • 1995
  • Emplacement ages for the granite plutons of the Jurassic and the Cretaceous times in the central Ogcheom Fold Belt were determined by Rb-Sr whole rock and mineral isocheon methods. In addition mineral ages for the plutons were determined by K-Ar and fission track methods. In turn, thermal histories and uplifting rates of the granitic bodies are elucidated from the isotopic ages. The Jecheon(~203 Ma) and Mungyeong(at lest~200 Ma) granites of the Jurassic and the Muamsa, Wolagsan and Daeyasan granites(~110 Ma) of the Cretaceous show high strontium initial ratios [$(^{87}Sr/^{86}Sr)_1$0.7100],suggesting that the granitic magmas have been generated by partial melting of crustal materials (S-type), or by mixing of mantle and crustal materials. Only mineral ages of the Sogrisan and Hyeongjebong granites (~90 Ma) were determined by K-Ar method, and petrogenesis of them were not defined yet. The two Jurassic granite plutons were cooled rapidly down to $300^{\circ}C$, right after the plutons were slowly cooled down since then, due to their deep emplacment. During the Middle Cretaceous period, the Jurassic Mungyeong granitic pluton was intruded and thermally affected much by the surrounding Wolagsan and Daeyasan granites. Accordingly the Rb-Sr mineral age, K-Ar hornblende and biotite ages of the Mungyeong granite appear to be reduced or reset due to the thermal effects above their blocking temperatures. All the cretaceous granites have been cooled much ore simply and rapidly down than the Jurassic ones below $300^{\circ}C$, owing to their shallow emplacement.

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북한 서한만 일대 석유자원 개발 현황과 남북한 협력 방안

  • Heo, Sik;Gwon, Seok-Jae;Yu, Hae-Su
    • 한국지구과학회:학술대회논문집
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    • 2005.09a
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    • pp.32-39
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    • 2005
  • 최근 들어 북한 서해안 일대의 원유매장 가능성에 대한 보도가 국내외 언론에 자주 오르내리고 있다. 실제 북한의 서한만 분지는 일일 생산량 450 배럴의 원유가 생산되고 있어 석유부존 가능성이 확인되었고, 중국에서 큰 유전중 하나인 발해만 유전지대와 지리적으로 근접해 있어 대규모 매장 가능성도 있다. 지금까지 밝혀진 북한 서한만의 지질은 중국의 발해만과 유사하다. 후기 원생대와 초기 고생대에 생성된 기반암 위에는 최대 6 ${\sim}$ 10 km 두께의 탄산염암 및 중생대 퇴적암과 4 ${\sim}$ 5 km 두께의 퇴적암이 집적되어 있다. 근원암은 3 km 이상 되는 쥐라기 흑색 셰일과 1 ${\sim}$ 2 km 두께의 백악기 흑색 셰일 그리고 수 km 두께의 중생대 이전의 탄산염암으로 구성되어 있다. 저류층은 높은 공극률을 가진 중생대부터 신생대에 퇴적된 사암과 중생대전에 균열된 탄산염암이다. 원유 트랩은 배사구조, 단층구조, 파묻혀 있는 언덕 그리고 층서형 트랩 형태다. 따라서 서한만에서의 퇴적층들은 다양한 형태의 근원암을 가지며 또한 공극률과 투수율이 높고, 많은 단층에 의한 이동경로를 가지게 되므로, 사암으로 이루어진 석유 저장지만 발견하면 석유를 생산할 수 있을 것으로 추정된다.

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Bird Tracks from the Gyeongsang Basin of the Korean Peninsula: A Paradise of Mesozoic Birds (중생대 새의 낙원 한반도 경상 분지에서 산출되는 새 발자국 화석)

  • Kim, Jeong Yul;Kim, Kyung Soo;Lim, Jong Deock
    • Korean Journal of Heritage: History & Science
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    • v.42 no.1
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    • pp.40-61
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    • 2009
  • The Cretaceous Gyeongsang Supergroup, composed of clastic sediments mostly deposited in the lacustrine and fluvial environment, is widely distributed in the southern part of the Korean Peninsula. Diverse fossils of plants, molluscs, insects, footprints of dinosaurs, pterosaurs and birds, and eggs, bones, and teeth of dinosaurs have been found from the Gyeongsang Supergroup. New types of dinosaur, pterosaur, and bird tracks recently discovered from the Gyeongsang Supergroup attract great attention from the world. Several tracksites of dinosaurs and birds were designated as Natural Monument and nationally conserved, and many efforts have given to them for nomination of UNESCO World Heritage. Bird tracks from the Gyeonsang Supergroup are Koreanaornis hamanensis, Jindongornipes kimi, Goseongornipes markjonesi, Ignotornis yangi, Uhangrichnus chuni, and Hwangsanipes choughi, which correspond approximately one third of Mesozoic bird tracks recorded from the world. The Gyeongsang Basin of the Korean Peninsula yields world most diverse bird tracks which may be called a paradise of Mesozoic birds and they are important natural heritage providing significant information about evolution and paleogeographic distribution of birds.