• 제목/요약/키워드: Basin history

검색결과 98건 처리시간 0.032초

영산강 유역 범람원 퇴적물의 화분분석 연구 (Vegetation History since the Mid-Lateglacial from Yeongsan River Basin, Southwestern Korea)

  • 최기룡;김기헌;김종원;김종찬;이기길;양동윤;남욱현
    • The Korean Journal of Ecology
    • /
    • 제28권1호
    • /
    • pp.37-43
    • /
    • 2005
  • 한반도 남서부 저지대의 식생변천사를 밝히기 위하여 영산강유역 범람원 퇴적물의 화분분석과 AMS 측정을 실시하였다. 그 결과 BS 1. 12,222cal BC$\sim$9,160cal BC: 냉온대 북부/고산지 침엽 활엽혼합림, BS 2. 9,160cal BC$\sim$4,210cal BC: 냉온대 중부/산지 낙엽활엽수림, BS 3. 4,210cal BC$\sim$125cal BC: 냉온대 남부/저산지 침엽 활엽혼합림, BS 4. 125cal BC$\sim$현재: 난온대/냉온대 남부/저산지 침엽수림의 식생변천과정을 밝힐 수 있었다. 소나무림의 증가는 4,210cal BC부터 이며 벼농사 개시 시기는 2,120cal BC부터 집약적으로 이루어지기 시작하였음을 밝혔다. 또한 후빙기 후기 소나무림의 급격한 증가는 농경의 집약화와 관계가 있음을 알 수 있었다.

중원역사문화권 설정의 의미와 활용 방안 (The Significance and Utilization of the Jungwon Historical and Cultural Area)

  • 성정용;양시은
    • 헤리티지:역사와 과학
    • /
    • 제54권3호
    • /
    • pp.204-227
    • /
    • 2021
  • 본 논문은 중원이라는 명칭이 갖고 있는 역사성과 그 시공간적인 범위를 개관해봄으로써 '역사문화권 정비 등에 관한 특별법'에 중원역사문화권 설정의 타당성과 필요성을 제기하고 중원역사문화권의 활용 방안을 함께 모색해보았다. 국토의 중심이라는 의미를 내포한 중원은 지리적으로는 충주를 중심으로 계립령과 죽령, 그리고 남한강과 북한강을 통해 남북으로 한반도를 이어주는 핵심 지역으로서의 전략적 가치를 가지고 있다. 고대 국가가 태동하는 마한 시기부터 서쪽으로는 미호천 유역인 청주와 진천 일대, 동쪽으로는 충주 일원이 서로 밀접하게 연결되어 있었으며, 이후 백제와 고구려·신라가 중원 지역을 차지하기 위해 치열한 접전을 벌이는 과정에서 삼국 문화의 교섭과 융합으로 중원 문화가 탄생하게 되었다. 특히 신라는 중원경을 중심으로 청주에는 서원경, 원주에는 북원경을 설치하는 등 중원 지역을 계속 중요시 하였다. 우리는 그간 고구려·백제·신라의 고대 국가 중심의 사관에 매몰되어 있다 보니 중원 지역에 대한 온전한 가치를 간과해왔는데, 앞으로는 중원역사문화권의 중요성을 인식하고 이를 어떻게 활용할 것인가에 대한 고민도 필요하다. 이를 위해 본 논문에서는 중원의 문화유산 생생 정보 공개 서비스, 지역 주민과 함께하는 역사문화유산 체험 및 교육프로그램, 문화유산을 적극 활용한 중원의 역사·문화·관광 콘텐츠의 개발 및 운영, 중원역사문화권의 정체성 규명을 위한 학술조사 및 연구의 활성화 등이 우선적으로 이루어져야 함을 제시하였다.

Approach for International Exchange of River Restoration Technology

  • Kazumasa, Ito
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2006년도 학술발표회 논문집
    • /
    • pp.45-50
    • /
    • 2006
  • About 50% of the population and 75% of the properties concentrate on the flood plain in Japan. The rivers have intimate relationship with our lives. Those conditions have been seen after modern river improvement projects that began about a century ago. The technology which was introduced from foreign countries was improved in conformity with geographical features and the climate condition of our nation, and has redeveloped as a Japanese original technology. In 1940's, Japan had serious natural disasters that were caused by large- scale typhoons. Those typhoons wiped out everything completely. Even though the government realized the importance of flood control and management after those natural disasters, civil work still aimed to economic development. Those construction works have become the one of factors for concentrating population and degrading natural environment in urban areas. Deterioration of river environment has become serious issue in urban development and main cause of pollution. The approaches for environmental restorations which were started about 30 years ago aimed to harmonize with nature environment and cities and human lives. There have been going on many projects called 'river environmental improvement projects', the 'nature friendly river works' and 'natural restoration projects.' The society has tried to find a way to live in harmony with nature. As for societies symbiotic with habitats will form the safe country in the history and the spectacle. Such as the symbiotic of the river or the basin where discharge, water quality, nature, the history, landscape, the local society and also for culture were built in is achieved. Examples of working, applied to restoration technologies and the one to describe the mechanism construction are been shown in the paper. Furthermore, write for an international spread of the river technology of Japan to attempt.

  • PDF

Thermal and uplift histories of Mesozoic granites in Southeast Korea: new fission track evidences

  • Shin, Seong-Cheon;Susumu Nishimura
    • 암석학회지
    • /
    • 제2권2호
    • /
    • pp.104-121
    • /
    • 1993
  • Fission track (FT) thermochronological analyses on Mesozoic granites provide new information about cooling and uplift histories in Southeast Korea. Twenty-nine new FT sphene, zircon and apatite ages and seven track length measurements are presented for eleven granite samples. Measured mineral ages against assumed closure temperatures yield cooling rates for each sample. Relatively rapid (7-$15^{\circ}C$/Ma) and simple cooling patterns from the middle Cretaceouss (ca. 90-100 Ma) granites are caused mainly by a high thermal contrast between the intruding magma and country rocks at shallow crustal levels (ca. 1-2.5 km-depths). On the contrary, a slow overall cooling (1-$4^{\circ}C$/Ma) of the Triassic to Jurassic granites (ca. 250-200 Ma), emplaced at deep depths (>>9 km), may mainly depend upon very slow denudation of the overlying crust. The uplift history of the Triassic Yeongdeog Pluton in the Yeongyang Subbasin, west of the Yangsan Fault, is characterized by a relatively rapid uplift (~0.4 mm/a) before the total unroofing of the pluton in the earliest Cretaceous (~140 Ma) followed by a subsidence (~0.2mm/a) during the Hayang Group sedimentation. Stability of original FT zircon ages (156 Ma) and complete erasure of apatite ages suggest a range of 3 to 5.5 km for the basin subsidence. Since 120 Ma up to present, the Yeongyang Subbasin has been slowly uplifted (~0.04 mm/a). The FT age patterns of Jurassic granites both from the northeastern wing of the Ryeongnam Massif and from the northern edge of the Pohang-Kampo Block indicate that the two geologic units have been slowly uplifted with a same mean rate (~0.04 mm/a) since early Cretaceous. Estimates of Cenozoic total uplifts since 100 Ma are different: Ryeongnam Massif (~6 km)=Pohang-Kampo Block (~6 km)>Yeongyang Subbasin(~4 km).

  • PDF

African Indigenous Cattle: Unique Genetic Resources in a Rapidly Changing World

  • Mwai, Okeyo;Hanotte, Olivier;Kwon, Young-Jun;Cho, Seoae
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제28권7호
    • /
    • pp.911-921
    • /
    • 2015
  • At least 150 indigenous African cattle breeds have been named, but the majority of African cattle populations remain largely uncharacterized. As cattle breeds and populations in Africa adapted to various local environmental conditions, they acquired unique features. We know now that the history of African cattle was particularly complex and while several of its episodes remain debated, there is no doubt that African cattle population evolved dramatically over time. Today, we find a mosaic of genetically diverse population from the purest Bos taurus to the nearly pure Bos indicus. African cattle are now found all across the continent, with the exception of the Sahara and the river Congo basin. They are found on the rift valley highlands as well as below sea level in the Afar depression. These unique livestock genetic resources are in danger to disappear rapidly following uncontrolled crossbreeding and breed replacements with exotic breeds. Breeding improvement programs of African indigenous livestock remain too few while paradoxically the demand of livestock products is continually increasing. Many African indigenous breeds are endangered now, and their unique adaptive traits may be lost forever. This paper reviews the unique known characteristics of indigenous African cattle populations while describing the opportunities, the necessity and urgency to understand and utilize these resources to respond to the needs of the people of the continent and to the benefit of African farmers.

Volcaniclastic Sedimentation of the Sejong Formation (Late Paleocene-Eocene), Barton Peninsula, King George Island, Antarctica

  • Yoo, Chan-Min;Choe, Moon-Young;Jo, Hyung-Rae;Kim, Yae-Dong;Kim, Ki-Hyune
    • Ocean and Polar Research
    • /
    • 제23권2호
    • /
    • pp.97-107
    • /
    • 2001
  • The Sejong Formation of Late Paleocene to Eocene is a lower volcaniclastic sequence unconformably overlain by upper volcanic sequence, and distributed along the southern and southeastern cliffs of the Barton Peninsula. The Sejong Formation is divided into five sedimentary facies; disorganized matrix-supported conglomerate (Facies A), disorganized clast-supported conglomerate (Facies B), stratified clast-supported conglomerate (Facies C), thin-bedded sandstone (Facies D), and lapilli tuff (Facies E), based on sedimentary textures, primary sedimentary structures and bed geometries. Individual sedimentary facies is characterized by distinct sedimentary process such as gravel-bearing mudflows or muddy debris flows (Facies A), cohesionless debris flows (Facies B),unconfined or poorly confined hyperconcentrated flood flows and sheet floods (Facies C), subordinate streamflows (Facies D), and pyroclastic flows (Facies E). Deposition of the Sejong Formation was closely related to volcanic activity which occurred around the sedimentary basin. Four different phases of sediment filling were identified from constituting sedimentary facies. Thick conglomerate and sandstone were deposited during inter-eruptive phases (stages 1, 3 and 4), whereas lapilli tuff was formed by pyroclastic flows during active volcanism (stage 2). These records indicate that active volcanism occurred around the Barton Peninsula during Late Paleocene to Eocene.

  • PDF

Intraspecific Molecular Phylogeny, Genetic Variation and Phylogeography of Reticulitermes speratus (Isoptera:Rhinotermitidae)

  • Park, Yung Chul;Kitade, Osamu;Schwarz, Michael;Kim, Joo Pil;Kim, Won
    • Molecules and Cells
    • /
    • 제21권1호
    • /
    • pp.89-103
    • /
    • 2006
  • Population structure was investigated in Reticulitermes speratus populations in the Korean Peninsula and the Japanese Archipelago. All trees derived from analyses of the combined sequence dataset of two mitochondrial genes, COII and COIII, showed that R. speratus populations cluster into two major clades comprising the Korean/southern Japanese populations and the northern Japanese populations. Analysis of population genetic structure showed strong genetic partitioning between populations of the two clades. To understand historical migration routes and current distributions, the phylogeographic history of R. speratus was inferred from intra-/interspecific phylogeny and divergence times estimated between the clades of the phylogenetic tree. The estimated migration route and divergence time of ancestral R. speratus are congruent with recent paleogeographic hypotheses involving land-bridge connections between the Asian continent and the Japanese Archipelago. We suggest that ancestral R. speratus separated into northern and southern Japanese populations after its migration into the Japanese main islands from East China during the early Pleistocene via the East China Sea basin, which may have been exposed during that period. The Korean populations seem to have diverged recently from southern Japanese populations; this may explain the current distribution of R. speratus in the Japanese Arachipelago, and account for why it is restricted to northern areas of the Tokara Strait.

대청도 옥죽동 사구의 형성과 최근의 변화 (Formation and Recent Changes of the Okjukdong Dunefield, Daecheong Island)

  • 최광희;공학양
    • 한국지형학회지
    • /
    • 제24권4호
    • /
    • pp.91-101
    • /
    • 2017
  • The Okjukdong dune in Daecheong Island attracts national attention because of its unique landscape that is not covered by vegetation. However, there has been little knowledge on the timing of the dune formation, associated wind regime, and conservational strategies. In this study, we used OSL dating and grain size analyses to reveal the history of the dune development. In addition, we analyzed the wind regime in the dunefield which is surrounded by artificial coastal forest. The fine sand at Okjukdong underlain by a colluvial gravel layer indicates that the dune has been developed since at least 5 ka. Aeolian sands were found to be deposited around 700 years ago. The dunefield appears to have been severely eroded 30~60 years ago. The dune landscape has been destroyed after constructing a windbreak forest around the dunefield. The sand seems to be moving south and north with the season.

The Trade Routes and the Silk Trade along the Western Coast of the Caspian Sea from the 15th to the First Half of the 17th Century

  • MUSTAFAYEV, SHAHIN
    • Acta Via Serica
    • /
    • 제3권2호
    • /
    • pp.23-48
    • /
    • 2018
  • The Silk Road usually implies a network of trade and communications that stretched from east to west and connected China and the countries of the Far East via Central Asia and the Middle East to the eastern Mediterranean, or through the northern coast of the Caspian Sea and the Volga basin to the Black Sea coast. However, at certain historical stages, a network of maritime and overland routes stretching from north to south, commonly called the Volga-Caspian trade route, also played a significant role in international trade and cultural contacts. The geopolitical realities of the early Middle Ages relating to the relationship of Byzantium, the Sassanid Empire, and the West Turkic Khaganate, the advance of the Arab Caliphate to the north, the spread of Islam in the Volga region, the glories and fall of the Khazar State, and the Scandinavian campaigns in the Caucasus, closely intertwined with the history of transport and communications connecting the north and south through the Volga-Caspian route. In a later era, the interests of the Mongolian Uluses, and then the political and economic aspirations of the Ottoman Empire, the Safavid State, and Russia, collided or combined on these routes. The article discusses trade contacts existing between the north and the south in the 15th and first half of the 17th century along the routes on the western coast of the Caspian Sea.

국립공원 주왕산의 지질과정과 지형경관 (Geological History and Landscapes of the Juwangsan National Park, Cheongsong)

  • 황상구;손영우;최장오
    • 암석학회지
    • /
    • 제26권3호
    • /
    • pp.235-254
    • /
    • 2017
  • 이 연구는 주왕산국립공원 및 주변에서 지질과 지형경관이 형성되는 지질과정을 엮은 것이다. 주왕산 지역은 선캠브리아누대 편마암류, 고생대 변성퇴적암류, 중생대 트라이아스기 심성암류, 백악기 퇴적암류, 심성암류와 화산암류, 그리고 신생대 제3기 화산암류와 제4기 애추로 구성되어 있다. 영남육괴의 선캠브리아 누대 편마암류와 고생대 변성퇴적암류는 포획체 혹은 현수체로 산출된다. 고생대 페름기부터 중생대 트라이아스기에는 북동부와 서부에 송림조산운동으로 대륙충돌 직전에 섭입환경에서 형성되는 마그마의 관입에 의해 영덕심성암체와 청송심성암체를 형성하였다. 청송심성암체는 후기의 화강섬록암의 관입으로 정편마암으로 변성되어 심성암복합체를 이루었으며, 구상 화강암과 약수탕의 지질명소를 가진다. 중생대 백악기에는 동아시아 대륙 밑으로 이자나기판의 섭입작용에 의해 한반도 남동부에 경상분지와 대륙성 화산호가 만들어졌다. 이 지역에서 영양소분지와 의성소분지가 분리되어 발달하면서 동화치층/후평동층, 가송동층/점곡층, 도계동층/사곡층 순으로 퇴적되었다. 도계동층 상부에는 대전사현무암이 주왕산 입구에 협재되어 있다. 백악기 후엽 75~77 Ma에는 남서부에서 심성작용이 일어나 부남암주를 형성하였다. 이때 규장질 마그마에 고철질 마그마가 혼합함으로 다양한 암상을 만들었다. 그리고 백악기 끝날 무렵(67 Ma)에는 안산암질 및 유문암질 마그마에 의해 여러 곳에서 화산작용이 일어나 주왕산의 몸체를 만들었다. 먼저 달산면으로부터 입봉안산암이 정치되었고, 지품면에서 지품화산암층, 청하면으로부터 내연산응회암, 달산면으로부터 주왕산응회암과 너구동층, 청하면으로부터 무포산응회암 순으로 형성되었다. 특히 주왕산응회암은 치밀용결대에서 냉각에 따른 수직절리에 의해 주상절리, 수많은 암석단애, 협곡, 동굴과 폭포 등의 많은 지질명소를 가진다. 신생대 제3기에는 여러 곳에서 유문암의 관입에 의해 병반, 암주와 암맥을 이룬다. 특히 북부에서 청송암맥군이 방사상으로 관입하고 있으며, 다양한 패턴의 꽃무늬를 갖는 구과상 유문암맥이 가치있는 지질명소를 이룬다. 제4기에는 애추가 중태산 병반과 무포산응회암의 급경사 아래에 형성되어 있다.