http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Colizza, Ester (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Kim, Sookwan,De Santis, Laura,Hong, Jong Kuk,Cottlerle, Diego,Petronio, Lorenzo,Colizza, Ester,Kim, Young-Gyun,Kang, Seung-Goo,Kim, Hyoung Jun,Kim, Suhwan,Wardell, Nigel,Geletti, Riccardo,Bergamasco, Elsevier 2018 Marine geology Vol.395 No.-
<P><B>Abstract</B></P> <P>Sedimentation processes influenced by late Cenozoic ice-sheet dynamics and bottom-current activity can be extracted from the seismic stratigraphic record of the Ross Sea continental slope and rise, where more continuous sedimentary successions are preserved compared to the continental shelf. In this study, we present a seismic stratigraphic analysis of the Central Basin that lies in the northwestern Ross Sea, using newly acquired and existing legacy seismic reflection data that are correlated to adjacent scientific drill sites. The chronostratigraphy of Ross Sea seismic sequences lying above the mid-Miocene sequence boundary (RSU4, ca. 16.5–15.5Ma) is based on the former Antarctic Offshore Stratigraphy (ANTOSTRAT) project. Depth-contour and isopach maps of sedimentary sequences bounded by two major unconformities of RSU4 and RSU2 (the late Pliocene boundary, ca. 4.0–2.8Ma) and the present-day seafloor were produced to illustrate the evolution of paleo-seafloor morphology, distribution of sediments and depocenter migration in the western Ross Sea outer margin.</P> <P>The results of seismic stratigraphic analysis indicate that gravity sedimentation processes dominated the Central Basin infill up to the mid-Miocene, and then downslope sediment supply gradually diminished through the late Miocene and Quaternary, likely reflecting a shift toward a cooler, less erosive glacial regime change. Since the late Pliocene, a topset-truncated glacial prograding wedge developed in the upper continental slope at the mouth of the Joides Basin and the sediment depocenter was shifted from the basin floor to the upper slope, suggesting the more persistent occurrence of grounded ice sheets on the outer continental shelf. Meanwhile, persistent along-slope bottom-current processes formed contourites on the slope and over the crests of banks surrounding the Central Basin since the mid-Miocene. In the late Pliocene, the contourites that formed off the Joides Basin mouth were overlain by glaciogenic debris flows, while the growth of contourites continued over and along the flanks of banks, farther to the north. This suggests that along-slope bottom-current processes near the Joides Basin mouth were diminished or dominated by the glacial discharge to the continental shelf edge. The sediment stacking patterns differ between the Joides/Central Basins and the Drygalski/Adare Basins located on the westernmost Ross Sea margin, suggesting that distinctive glacial/interglacial behavior of the former grounded ice streams and sediment supplies in the troughs feeding these basins were largely controlled by the paleo-seafloor morphology of the western Ross Sea continental shelf.</P> <P><B>Highlights</B></P> <P> <UL> <LI> First seismic stratigraphic analysis of the Central Basin, northwestern Ross Sea. </LI> <LI> Gravity and bottom-current controlled sedimentary features are observed. </LI> <LI> Distinctive paleo-seafloor morphology and depocenter migration are indicated. </LI> <LI> Ice sheet shifted toward polar-style glacial regime during the late Cenozoic. </LI> <LI> Bottom-current activity changed near the paleo-shelf edge after late Pliocene. </LI> </UL> </P>
-
남극 로스해 펜넬-이젤린 퇴 동쪽 대륙사면의 코어 RS14-GC2의 점토광물의 기원지 연구
하상범 ( Sangbeom Ha ),김부근 ( Boo-keun Khim ),조현구 ( Hyen Goo Cho ),에스터콜리자 ( Ester Colizza ) 한국광물학회 2018 광물과 암석 (J.Miner.Soc.Korea) Vol.31 No.1
남극 로스해 펜넬-이젤린 퇴의 동쪽 대륙사면에 위치한 정점 RS14-C2에서 2014년 PNRA XXIX 탐사(Rosslope II Project)동안 중력코어(RS14-GC2)를 획득하였다. 퇴적물의 기원지 추정을 위하여 대자율, 모래 입자 함량, 점토광물 조성을 분석하고 AMS 14C 연대를 측정하였다. 퇴적물은 주로 빙운쇄설물을 포함한 반원양성 사질 점토 또는 실트질 점토로 구성되어 있다. 코어의 최상부 연대는 현생 퇴적물과 홀로세 퇴적물을 지시한다. 방사성 탄소동위원소 연대와 퇴적물의 색, 대자율 및 모래입자 함량을 이용하여 코어 퇴적물을 간빙기와 빙하기 퇴적물로 구분하였다. 간빙기의 갈색퇴적물은 대자율과 모래 입자 함량이 낮은 반면에 빙하기의 회색퇴적물은 대자율과 모래 입자 함량이 높다. 코어 퇴적물의 점토광물 조성은 전체적으로 일라이트(61.8~76.7%)가 가장 우세하며, 녹니석(15.7%~21.3%), 카올리나이트(3.6%~15.4%), 그리고 스멕타이트(0.9~5.1%)의 순서로 나타나고, 간빙기와 빙하기/후빙기로 뚜렷하게 구분된다. 빙하기 동안 일라이트와 녹니석 함량이 우세한 것은 퇴적물의 기원지가 주로 로스해 빙상 하부에 위치한 남극종단산맥의 기반암을 지시하기 때문이다. 반면 빙상 후퇴에 의한 일라이트와 녹니석의 공급이 감소되어 간빙기 동안 상대적으로 스멕타이트 함량이 약간 증가하며 카올리나이트 함량은 많이 증가한다. 더불어 간빙기 동안 로스해 서안의 빅토리아랜드 연안의 맥머도 화산군에서 북동쪽으로 흐르는 해류에 의해 스멕타이트가 추가로 공급되며, 카올리나이트는 카올리나이트의 함량이 풍부한 퇴적암이 분포하는 에드워드 7세 반도에서 공급되고 대륙사면류에 의해 대륙사면으로 운반되었을 것으로 예상된다. A gravity core (RS14-C2) was collected at site RS14-C2 in the continental slope to the east of Pennell-Isellin Bank of the Ross Sea (Antarctica) during PNRA XXIX (Rosslope II Project) Expedition. In order to trace the sediment source, magnetic susceptibility (MS), sand fraction, and clay mineral compositions were analyzed, and AMS 14C ages were dated. Core sediments consist mostly of hemipelagic sandy clay or silty clay including ice-rafted debris (IRD). AMS 14C age of core-top indicates the modern and Holocene sediments. Based on AMS 14C dating, sediment color, MS and sand fraction, core sediments are divided into interglacial and glacial intervals. The interglacial brown sediments are characterized by low MS and sand fraction, whereas the glacial gray sediments are characterized by high MS and sand fraction. Among clay mineral compositions of core sediments, illite is highest (61.8~76.7%), and chlorite (15.7~21.3%), kaolinite (3.6~15.4%), and smectite (0.9~5.1%) are in decreasing order, and these compositions are also divided into the interglacial and glacial/deglacial intervals. During the glacial period, the high content of illite and chlorite indicate sediment supply from the bedrocks of Transantarctic Mountains under the Ross Ice Sheet. In contrast, because of decreasing supply of illite and chlorite by the glacial retreat, smectite and kaolinite contents increased relatively during the interglacial period. During the interglacial period, smectite may be transported additionally by the northeastward flowing surface current from the coast of Victoria Land in the western Ross Sea. Kaolinite may be also supplied to the continental slope by the Antarctic Slope Current from the kaolin-rich metasedimentary rock outcropped on the Edward VII Peninsula.
코리아스칼라연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
