• Title/Summary/Keyword: Directorate of Geoscience

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Analysis on New Research Opportunities and Strategies for Earth Sciences in the United States (미국 지질과학분야 신규 연구주제 및 전략분석)

  • Kim, Seong-Yong;Ahn, Eun-Young;Bae, Jun-Hee;Lee, Jae-Wook
    • Economic and Environmental Geology
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    • v.49 no.1
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    • pp.43-52
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    • 2016
  • The essential role of the Division of Earth Sciences(EAR) in the Directorate of Geoscience(GEO) of National Science Foundation of America(NSF) is to support basic research aimed at acquiring fundamental knowledge of the Earth system that can be directly applied to the United States' strategic needs. The 2011 Committee on New Research Opportunities in the Earth Sciences(NROES) of the National Academy of Sciences(NAS) identified specific areas of the basic earth science research scope of the EAR that were poised for rapid progress during the next decade. Quantified by interdisciplinary approaches, the Committee highlighted the following topics relating to the EAR Deep Earth Processes and Surface Earth Processes sections: (1) the early Earth; (2) thermochemical internal dynamics and volatile distribution; (3) faulting and deformation processes; (4) interactions among climate, the Earth surface processes, tectonics, and deep Earth processes; (5) co-evolution of life, environment, and climate; (6) coupled hydrogeomorphic-ecosystem response to natural and anthropogenic change; and (7) interactions of biogeochemical and water cycles in terrestrial environments. We also promote future research challenges such as the critical zone studies. In order to promote more active such a huge future research challenges, additional research support policies are needed.

Drone based Magnetic Anomaly Detection to detect Ferromagnetic Target (강자성 표적 탐지를 위한 드론 기반 자기 이상 탐지)

  • Sin Hyuk Yim;Dongkyu Kim;Ji Hun Yoon;Bona Kim;Eun Seok Bang;Kyu Min Shim;Sangkyung Lee;Jong-shick Oh
    • Journal of the Korea Institute of Military Science and Technology
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    • v.26 no.4
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    • pp.335-343
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    • 2023
  • Drone based Magnetic Anomaly Detection measure a magnetic anomaly signal from the ferromagnetic target on the ground. We conduct a magnetic anomaly detection with 9 ferromagnetic targets on the ground. By removing the magnetic field measured in the absence of ferromagnetic targets from the experimental value, the magnetic anomaly signal is clearly measured at an altitude of 100 m. We analyze the signal characteristics by the ferromagnetic target through simulation using COMSOL multiphysics. The simulation results are within the GPS error range of the experimental results.

Occurrence and Formation Environment of Boron Deposits in Turkey (터키 붕소광상의 부존특성 및 형성환경)

  • Koh, Sang-Mo;Lee, Bum Han;Lee, Gilljae;Cicek, Murat
    • Economic and Environmental Geology
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    • v.47 no.5
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    • pp.541-549
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    • 2014
  • The annual borate production in Turkey is about 3 million tons, which occupies approximately 61 percent of total annual world production. Turkey has five boron deposits including Bigadic, Emet, Kestelek, Kirka, and Sultancayir. At present, Bigadic, Emet, and Kirka deposits are operating. Kirka boron deposit is distributed within volcanoclatic sedimentary group as mainly layered, rarely brecciated and massive types. Major borate is borax associated with colemanite and ulexite. They show a horizontal symmetrical zonation from Na borate (borax) in the center of deposit to Na-Ca borate (ulexite) and Ca-borate (colemanite) in margin. Bigadic boron deposit is known as the largest colemanite deposit in the world. This deposit occurs as two borate bearing horizons in Miocene volcanoclastic sedimentary group. Thickness ranges from several meters to 100 meter with a length of several hundreds meters. Borate ore bodies which are mainly composed of colemanite and ulexite are alternated with claystone, mudstone, tuff and layered limestone as lenticular shape. Sultancayir boron deposit is mainly distributed within gray limestone. Main borate minerals of this deposit are pandermite and ulexite. Pandermite and ulexite occur as colloform aggregate and small veinlet, respectively. Turkish boron deposits are evaporite deposit which were formed in Miocene playa-lake environment. Boron was supplied to the deposits by the volcanic and hydrothermal activities.

Lithium Extraction from Smectitic Clay Occurring in Lithium-bearing Boron Deposits in Turkey (터키 리튬 함유 붕소광상에서 산출하는 스멕타이틱-점토로부터의 리튬 추출)

  • Lee, Won-Jong;Yoon, Soh-joung;Chon, Chul-Min;Heo, Chul-Ho;Lee, Gill-Jae;Lee, Bum-Han;Cicek, Murat
    • Journal of the Mineralogical Society of Korea
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    • v.29 no.4
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    • pp.167-177
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    • 2016
  • Smectitic clays, occurring in Kırka and Bigadiç boron evaporite deposits formed in Miocene playa lake environment in Turkey, contain $LiO_2$ 0.02-0.21% and 0.16-0.30%, respectively, and boron tailings are also reported to contain $LiO_2$ 0.04-0.26%. Lithium in smectitic clays was identified to be retained in hectorite. The XRD results revealed that hectorite was contained in 25.7% and 79.7% of Kırka and Bigadiç deposit samples respectively. In this study, we selected a clay sample from each deposit with lithium content of ~0.18% and estimated extractable lithium by acid treatment and roasting method commercially applicable to lithium resources, such as lepidolite and hectorite. When 1 g of crushed clay (particle size less than $74{\mu}m$) was reacted with 200 mL of 0.25 M HCl solution, the amount of lithium dissolved increased with the increase of reaction time up to 10 hours for both samples. Reaction time longer than 10 hours did not significantly increased the amount of lithium dissolved. After 10 hours of reaction, 89% of lithium in the clay sample from the Kırka deposit was dissolved, while 71% of lithium was dissolved from the Bigadiç deposit tailing sample. 87% of lithium in the clay sample from the Kırka deposit was extracted and 82% of lithium was extracted from the Bigadiç deposit tailing sample by the roasting extraction method, where clays were leached after a thermal treatment at $1,100^{\circ}C$ for 2 hours with $CaCO_3$ and $CaSO_4$.