RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • SCISCIESCOPUS

        Potassium isotope fractionation between K-salts and saturated aqueous solutions at room temperature: Laboratory experiments and theoretical calculations

        Li, Weiqiang,Kwon, Kideok D.,Li, Shilei,Beard, Brian L. Pergamon Press 2017 Geochimica et cosmochimica acta Vol.214 No.-

        <P><B>Abstract</B></P> <P>Improvements in mass spectrometry have made it possible to identify naturally occurring K isotope (<SUP>39</SUP>K/<SUP>41</SUP>K) variability in terrestrial samples that can be used in a variety of geological and biological applications that involve cycling of K such as clay or evaporite formation. However, our ability to interpret K isotope variability is limited by a poor understanding of how K isotopes are fractionated at low temperatures. In this study, we conducted recrystallization experiments of eight K-salts in order to measure the K isotope fractionation factor between the salt and the saturated K solution (Δ<SUP>41</SUP>K<SUB>min-sol</SUB>). Measured Δ<SUP>41</SUP>K<SUB>min-sol</SUB> are +0.50‰ for K<SUB>2</SUB>CO<SUB>3</SUB>·1.5H<SUB>2</SUB>O, +0.32‰ for K<SUB>2</SUB>SO<SUB>4</SUB>, +0.23‰ for KHCO<SUB>3</SUB>, +0.06‰ for K<SUB>2</SUB>C<SUB>2</SUB>O<SUB>4</SUB>·H<SUB>2</SUB>O, +0.02‰ for KCl, −0.03‰ for K<SUB>2</SUB>CrO<SUB>4</SUB>, −0.15‰ for KBr, and −0.52‰ for KI. Overall the Δ<SUP>41</SUP>K<SUB>min-sol</SUB> decreases with increasing <I>r</I> for K in crystals, where <I>r</I> is the average distance between a K atom and its neighboring atoms of negative charge. Salts with monovalent anions and salts with divalent anion complexes define different linear trends with distinct slopes on a plot of Δ<SUP>41</SUP>K<SUB>min-sol</SUB> - <I>r</I>. We applied <I>ab initio</I> lattice dynamics and empirical crystal-chemistry models to calculation of K isotope fractionation factors between K salts; both methods showed that the calculated inter-mineral K isotope fractionation factors (Δ<SUP>41</SUP>K<SUB>min-KCl</SUB>) are highly consistent with experimentally derived Δ<SUP>41</SUP>K<SUB>min-KCl</SUB> under the assumption of consistent β factors for different saturated K solutions. Formulations for the crystal-chemistry model further indicate that both anion charge and bond length <I>r</I> are the principle controlling factors for K isotope fractionation, and the K isotope fractionation factors correlate with <I>r</I> following a 1/<I>r</I> <SUP>3</SUP> relationship. Our experiment and theoretical study confirms the existence of significant equilibrium K isotope fractionation at ambient conditions, and the K isotope fractionation factors for halides and sulfate obtained in this study provide a basis for future K isotope studies on evaporites.</P>

      • KCI등재

        Geochemical attributes of late Neoproterozoic Salt Range Formation, Pakistan: constraints on provenance, paleoclimate, depositional and tectonic settings

        Muhammad Ahmed Farooqui,Muhammad Umar,Muhammad Amjad Sabir,Rashid Pervez,Tarib Jalees 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.2

        Detailed geochemical analyses of clastic fraction of the oldest exposed Salt Range Formation in the famous salt producing region (Salt and Trans-Indus Ranges) Pakistan was carried out in order to understand provenance, paleoclimate, depositional and tectonic settings. Sandstone and shale samples of Salt Range Formation were analysed for major, trace and rare earth elements and various geochemical models and ratios were used to interpret. Geochemical analyses of both sandstone and shale fraction mostly display similar results and interpretations. The samples are classified as arkose, subarkose, litharenites and were sourced from felsic and/or intermediate igneous rocks. The sedimentation of the detritus was occurred in fluvial to restricted shelf conditions under arid to semi-arid and oxygenated climate conditions. The tectonic settings of the sediments were mainly Oceanic and Continental Island arcs as well as Active Continental margin.

      • KCI등재SCOPUS

        천연기념물 진주 충무공동 익룡·새·공룡발자국 화석산지의 오염물 형성 메커니즘과 관리방안

        최명주(Myoungju Choie),원상호(Sangho Won),이태종(Tea Jong Lee),이성주(Seong-Joo Lee),공달용(Dal-Yong Kong),이명성(Myeong Seong Lee) 대한자원환경지질학회 2023 자원환경지질 Vol.56 No.6

        익룡 발자국의 개체 및 밀집도 측면에서 세계 최대 규모로 알려진 진주 충무공동 익룡·새·공룡발자국 화석산지는 2011년 천연기념물로 지정된 이래, 2018년 일부 화석층을 현장 보존하기 위해 보호각을 설치하였다. 이 중 제2보호각에 관리중인 화석층은 기 보고된 발자국 중 약 17%에 달하는 익룡·수각류·조각류 발자국(총 679개)이 단일 층준에서 발견되어 학술적 가치가 크지만 물리적, 화학적 손상이 지속적으로 발생하여 발자국의 관찰에 어려움이 있다. 특히 화석층 표면을 피복하는 유백색 오염물은 석고와 대기오염물로 구성된 복합체의 누적현상에서 기인한다. 오염물을 구성하는 석고는 화석층 하부층준에서 기원한 칼슘과 잔디의 생육활동으로 공급되는 황이 보호각 후방의 잔디가 식재된 토양층에서 집수된 지하수에 의해 용출되고, 보호각의 일대의 수분 순환 과정에서 화석층 표면에 증발잔류하며 결정화된다. 또 다른 오염물 구성체인 화분·광물 등은 분진 배출이 어려운 보호각 갤러리창을 통해 풍성으로 유입된다. 따라서 상이한 기원을 가진 두 오염물로부터 화석층을 보존하기 위해서는 보호각의 수분 및 대기 순환 제어와 지속적인 오염물 제거가 필요하다. 분진상의 석고와 대기 오염물은 스팀 세정법으로 충분한 제거 효과가 있으며, 암회색 셰일인 화석층은 레이저 흡수능이 커 흔적화석과 퇴적구조의 물리적 손실을 동반하는 레이저 세정법은 가급적 지양하는 것이 바람직하다. Tracksite of pterosaurs, birds, and dinosaurs in Chungmugong-dong in Jinju was designated as a natural monument in 2011 and is known as the world's largest in terms of the number and density of pterosaur footprints. This site has been managed by installing protection buildings to conserve in 2018. About 17% of the footprints of pterosaur, theropod, and ornithopod in this site under management in the 2nd protection building are of great academic value, but observation of footprints has difficulties due to continuous physical and chemical damage. In particular, the accumulation of milk-white contaminants is formed by the gypsum and air pollutant complex. Gypsum remains evaporated with a plate or columnar shape in the process of water circulation around the 2nd protection building, and the dust is from through the inflow of the gallery windows. The aqueous solution of gypsum, consisting of calcium from the lower bed and sulfur from grass growth, is catchmented into the groundwater from the area behind the protection building. Pollen and a few minerals other constituents of contaminants, go through the gallery window, which makes it difficult to expel dust. To conserve the fossil-bearing beds from two contaminants of different origins, controlling the water and atmospheric circulation of the 2nd protection building and removing the contaminants continuously is necessary. When cleaning contaminants, the steam cleaning method is sufficiently effective for powder-shaped milk-white contaminants. The fossil-bearing bed consists of dark gray shale with high laser absorption power; the laser cleaning method accompanies physical loss to fossils and sedimentary structures; therefore, avoiding it as much as possible is desirable.

      • KCI등재

        북부 아르헨티나 붕산염 광상 조사: 살리나스그란데스 광상을 중심으로

        박상준,이한영 한국지구과학회 2009 韓國地球科學會誌 Vol.30 No.7

        The Salinas Grandes borate deposit located in Jujuy state, northern Argentina can be categorized into the playatype evaporite deposit. Major borate mineral is ulexite (NaCaB5O9·H2O), which boron could be originated from volcanic rocks nearby playa. The eastern part of the Jujuy state in northern Argentina belongs to the Altiplano-Puna platform which shows high altitude and semiarid climate. Lots of Mesozoic and Cenozoic volcanics that are source of boron as well as playas that are the basin for borate precipitation in the area are essential for boron evaporite deposit. Therefore, the extensive explorations for the playa-type evaporite deposit are need. 북부 아르헨티나 후후이주 동부에 위치하는 살리나스그란데스 붕산염(borate) 광상은 플라야 주변부에 배태되는 플라야(playa)형 증발광상이다. 이 광상에서 산출되는 붕산염광물은 주로 울렉사이트(ulexite, NaCaB5O9·H2O)로 붕소의 주 공급원은 주변 화산암일 것으로 추정된다. 아르헨티나 후후이주 동부는 아건조 기후의 알티플라노-푸나 고평원에 위 치한다. 중생대 및 신생대 화산암체는 붕소의 주요 공급원으로 생각되며, 플라야는 이들 붕소가 침전되는 주요 분지 역 할을 하여 이 지역은 붕소의 이동과 침전을 위한 좋은 지형적·지구조적 조건을 보인다. 따라서 향후 이 지역의 붕산염 광체에 대한 지속적인 탐사가 필요 할 것으로 생각된다.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼