• The Journal of the Petrological Society of Korea
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• v.11 no.1
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• pp.17-28
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• 2002

This study has been designed to elucidate the petrography and geochemical characteristics of the Taeheung-ri lava in southeastern Jeju Island. The lava is divided into the alkaline basalt and tholeiitic basalt. More than 4 layers of tholeiitic basalt are overlain by layers of alkaline basalt. Compared with alkaline basalt, tholeiitic basalt has lower contents of $K_2O$, $P_2O_5$, Ba and Ta, but slight higher contents of $SiO_2$ and CaO. The contents of Ba and Rb of all basalts are enriched, but those of Ni and Cr are depleted compared with primitive mantle compositions. All basalts show inclined chondrite-normalized REE patterns with LREE enriched more than HREE and alkaline basalt has relatively higher. The basalts of this study area are plotted in the field of within plate basalt on the tectonomagmatic discrimination diagram. Tholeiitic basalt has higher ratios of Zr/Nb, Y/Nb, and $Al_2O_3/P_2O_5$ than alkaline basalt. Both tholeiitic and alkaline basalt are similar in their K/Ba ratios. The geochemical data suggest that the parental magma of both basalts might be produced by different degrees of partial melting of similar source mantle. The tholeiitic basalt formed by higher degree of partial melting than the alkaline basalt.

• Proceedings of the Speleological Society Conference
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• 1992.07a
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• pp.29-30
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• 1992

협재굴을 포함한 표선리 현무암은 알칼리암굴로 구성된 제주도 화산암의 일원으로서 일본열도 아래로 섭입하고 있는 태평양판 및 필리핀판과는 관계가 없으며 도리어 대서양 및 하와이의 암류와 규를 같이 한다. 표선리 현무암은 제주도 형성기의 초기인 제 2분출기에 유출된 감람석 현무암이다. 표선리 현무암은 다른 현무암에 비하여 동굴 생성에 유리한 조건을 가진 화산암인 것으로 보인다.(중략)

• Journal of the Korean earth science society
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• v.26 no.1
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• pp.78-92
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• 2005

Petrographical and petrochemical analyses for late Miocene basalts in Goseong-gun area. Gangwon province, were carried out to interpret the characteristics and the origin of magma. The basaltic rocks occurred as plug-dome in the summit of several small mountain and developed columnar jointing with pyroxene-megacryst bearing porphyritic texture. And the basalt contains xenoliths of biotite granite (basement rocks), gabbro (lower crustal origin) and Iherzolite(upper mantle origin). The basalts belong to the alkaline basalt field in TAS diagram and partly belong to picrobasalt and trachybasalt field. On the tectonomagmatic discrimination diagram f3r basalt in the Goseong-gun area. they fall into the fields for the within plate and oceanic island basalt. The characteristics of trace elements and REEs shows that primary magma for the basalt magma would have been derived from partial melting of garnet-peridotite mantle. This late Miocene basalt volcanism is related to the hot spot within the palte.

• Journal of the Korean earth science society
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• v.34 no.2
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• pp.109-119
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• 2013

Duibaejae basalts from Goseong, Gangwon-do, are divided into the lower basalt and the upper basalt depending on the properties, such as occurrence, mineral compositions, and major and trace compositions of the basalts. The lower basalts have characteristics of agglomerate rocks as well as contain, crustal and mantle xenoliths, and olivine, pyroxene, and plagioclase xenocrysts. The upper basalts with columnar joints contain relatively more mantle xenolith and olivine xenocryst than the lower basalts. The major and trace element compositions suggest that the composition of the upper basalts is close to primary magma composition. Enrichment and depletion patterns of the trace and the rare-earth elements of the lower basalts are similar to those of the upper basalts, whereas the lower basalts are more LREE enriched than the upper basalts. The source magmas of the lower and upper basalts from Duibaejae volcanic edifice were generated from about 0.8-1.2% and 3.7-4.0% batch melting of garnet peridotite, respectively. The abundance of granite xenolith, and plagioclase and quartz xenocrysts with reaction rim indicates that the lower basalts, compared with upper basalts, might have been assimilated with the crustal materials during ascending to surface.

• Journal of the Korean earth science society
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• v.28 no.3
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• pp.324-342
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• 2007

This study reports petrography and geochemical characteristics of the basalt lava flows in Seongsan-Ilchulbong area, the easternpart of Jeju island, Korea, to understand the evolutionary processes of magma. Basalt lavas are classified into the Pyoseon-ri basalt and the Seongsan-ri basalt. The Pyoseon-ri basalt is dark-gray colored with many vescicles, and mainly consists of olivine, feldspar and rarely of clinopyroxene as phenocrysts. The Seongsan-ri basalt is largely aphanitic basalt and bright-gray colored, divided into two lava-flow units: lower lava flow (B1) and upper lava flow (B2) by the intercalated yellowish lapillistone and paleosol. The lavas plotted into sub-alkaline tholeiitic basalt and alkaline basalt series. The tholeiitic basalts have characteristically higher $SiO_2,\;FeO^T$, and CaO contents, but lower $TiO_2,\;K_2O,\;P_2O_5$ and other incompatible elements compared to the alkali basalts. The tholeiitic basalts have higher $SiO_2$ to the same MgO contents than the alkalic basalts. The contents of Ni, Cr, and MgO show a strong positive correlation, which indicates that low-MgO phases like plagioclase and titanomagnetite were important during the differentiation of magma. The contents of incompatible elements against that of Th show a strong positive correlation. The chondrite-nomalized REE patterns of tholeiitic and alkalic basalts are subparallel each other. LREEs contents of the former are lower than, but HREEs contents are similar to the latter. They both are similar to their K/Ba ratios. The primitive-mantle normalized spider diagram demonstrates that the contents of Ba and Th of all basaltic magma are enriched, and yet Cr, Ni are depleted. The tholeiitic and alkalic basalts may be originated from a different degree of the partial melting of the same mantle material source, and one shows a higher degree of the partial melting than the other.

• The magazine of the Korean Society for Advanced Composite Structures
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• v.5 no.4
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• pp.21-28
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• 2014

최근 증가하는 현무암 석분슬러지를 건설재료로 재활용하기 위한 방안으로, 시멘트 몰탈에서 잔골재의 일부를 현무암석분슬러지로 대체한 후, 기능성 마감재로서의 성능을 검증한 결과 다음과 같은 결과를 얻었다. 1. 현무암 석분슬러지를 포함한 몰탈의 휨인장강도와 압축강도는, 대체율 21%에 도달할 때까지 압축 및 휨인장강도는 일반 시벤트몰탈 대비 각각 47%와 35% 증가하였다. 2. 원적외선 방사율에 있어서도 기존몰탈보다 높은 0.933까지 이르렀으며, 이 수치는 기타 기능성 마감재보다 우수한 원적외선 방사율을 나타내는 것이다. 3. 음이온 방사량은 현무암석분의 대체율에 따른 일관된 경향을 보이지는 않았으나, 일반 시멘트몰탈 보다는 5% ~ 12% 증가효과가 나타났다. 4. 기존 시멘트몰탈의 잔골재의 21%를 현무암석분슬러지로 대체할 경우, 시멘트 몰탈보다 물리적 성질이 증가 함과 동시에, 기능성몰탈로서의 원적외선 방사율, 음이온 방사량의 증진효과가 있었다. 또한 새로운 건축자재의 생산을 통한 경제적 이득은 물론, 산업폐기물의 양을 줄일 수 있다.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.33-36
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• 2008

For the past 300 Ma, massive extinctions are associated with major flood basalt eruptions. The geomagnetic Superchrons (Cretaceous Normal Superchron, Kiaman Long Reversed Superchron, Moyero Long Reversed Superchron) precede the major flood basalt eruptions and massive extinctions. It is likely that upswing of mantle plumes is responsible for the generation of continental flood basalt. Eruption of flood basalts results in a catastrophic climate change as well as a massive genus depletion.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.1
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• pp.84-89
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• 2015

Basalt fiber has many advantages as a reinforcing fiber such as high tensile strength and similar density to concrete. This study investigated the bonding property and the effect of fiber orientation on tensile strength of basalt fiber. Single fiber pullout tests for basalt and polyvinyl alcohol (PVA) fibers were performed to evaluate the bonding property between basalt fiber and mortar. And then tensile strength of basalt, PVA, and polyethylene (PE) fibers according to fiber orientation were measured. From the test results, it was exhibited that the chemical bond, frictional bond, and slip-hardening coefficient of basalt fiber were 1.88, 1.03, 0.24 times of PVA fibers, respectively. And the strength reduction coefficient of basalt fiber was 9 times of PVA fiber and 3 times of PE fiber.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.449-456
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• 2013

This study was carried out to assess the suitability in terms of the standards of material quality of basalt aggregates from JEJU Island as a source for concrete aggregate. Quality assessments on the basalt aggregates were performed to assess the soundness of coarse aggregates using sodium sulfate solution, aggregate crushing test, and Los Angeles abrasion test. In addition, XRD, XRF, porosity, and compressive and tensile strength tests were performed to analyze the chemical components and the mechanical properties. In general, the mechanical properties of basalt aggregates from some areas did not meet the Korea Standards (KS), but the levels of compressive and tensile strength were higher than those of granite, andesite, and sandstone of other regions.

• Journal of the Korean earth science society
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• v.21 no.5
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• pp.553-562
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• 2000

Daejeonsa basalt in the Mt. Juwang area is composed of 12 lava flows alternate with 9 peperites, and each lava and peperite has variable thickness. Globular peperites yielded in Daejeonsa basalt are mixed basalt clasts with reddish shale. Based on field description, when lava flows over unconsolidated wet shale or injectes into unconsolidated wet shale, peperites were formed at the contacts between lava and shale. Daejeonsa basalt are massive lava flows with rare vesicules: some vesicules are found in upper part of a flow unit. The basalt has mainly pseudomorphs of olivine as phenocryst, and also plagioclase and clinopyroxene phenocrysts in rocks with higher Mg-number. Matrix is mainly subophitic texture, sometimes showing ophitic and intergranular textures due to different cooling rate. Clinopyroxene is augite(Wo$_{41.6}$En$_{45.1}$Fs$_{13.3}$), and plagioclase is mostly labradorite(An$_{55.0}{\sim}_{67.7}$), but some is andesine(An$_{44.3}$) and bytownite(An$_{74.5}$). Oxide minerals are composed of titanomagnetite and ilmenite.