• 동굴
• /
• 제19권20호
• /
• pp.29-62
• /
• 1989

Cheju Island, which was formed by volcanic activity, is an oval in its shape with the major axis 80km and the minor axis of 40km. The island holds in its heart Mt. Hanala rising 1,950m above the sea. Petrological study of this volcanic island has been made actively by Sang-Man Lee, Chong-Kwang Won and Moon-Won Li. The chronological measurements of the island by Chong-Kwan Won and Moon-Won Lee showed that it is composed of Sanbangsan trachytes and Backlokdam trachytes(25,000 year ago). These reports are based on the chemical analysis and the rediometric chronological measurements on the ground. However, there has been no reports about the inside of caves. We made an (composition) analysis of the inside of Manjang Cave by the fundamental parameter method in X-ray fluorescence spectrometry. The fundamental parameter method in X-ray fluorescence spectrometry is nondestructive analysis. and it enables us to make the values processed by a computer. The results obtained by this methods are as follows: SiO$_2$(49％), $Al_2$O$_3$(17％), Fe$_2$O$_3$(13％), CaO(8.1％), MgO(5.5％), Na2O(3.6％), TiO$_2$(2.1％), $K_2$O(0.86％), P$_2$O$_{5}$(0.28％), and MnO(0.20％) respectively. The data obtained by the fundamental parameter method in X-ray fluorescene was compared with the data provided by Chong-Kwan Won and Moon-Won Lee. Our measurement was made by K-Ar-method in cooperation with T. ITAYA. The samples are of 30,000-420,000 years ago. The composition of the values of our underground analysis with the existing values obtained by the analyses on the ground produced new data about Cehju volcanic island.d.

• 한국지구과학회지
• /
• 제33권7호
• /
• pp.618-626
• /
• 2012

2007년 11월에 천연기념물 제487호로 지정된 화순군 서유리의 백악기 화석산지는 수각류 발자국 보행렬, 식물화석, 건열, 연흔, 수평층리 등 고환경을 연구하는데 중요한 자료들을 포함한다. 이 백악기 퇴적층은 하부에 직경 5-40 cm의 다양한 성분의 화산암역을 함유하며, 후기의 화순안산암에 의해 덮인다. 백악기 퇴적층과 동시퇴적된 6시료의 화산암역과 이 지층을 덮는 화순안산암 2시료를 대상으로 전암을 이용한 K-Ar법 절대연대측정을 실시하였으며, 그 결과 백악기말의 투로니안(90-70 Ma)에서 신생대 초기인 플라이오세($63.4{\pm}1.2$, $62.1{\pm}1.2$ Ma)에 해당한다. 연대측정 결과 백악기 퇴적층의 퇴적시기와 공룡의 활동시기에 대한 최대지질연대는 약 70 Ma이다. 이 연대는 여수 사도지역에서 공룡발자국을 포함하는 백악기층의 퇴적시기(71-66 Ma)와 서로 대비될 가능성을 시사한다.

• 자원환경지질
• /
• 제26권1호
• /
• pp.55-65
• /
• 1993

Udo Island, some 3 km off the coast of Sungsan Peninsula at the eastern promontory of Cheju Island, occurs in such a regular pattern on the sequences which reprent an excellent example of an eruptive cycle. The island comprises a horseshoe-shaped tuff cone, a nested cinder cone on the crater floor, and a lava delta which extends over northwest from the moat between two cones. The volcanic sequences suggest volcanic processes that start with emergent Surtseyan eruption, progress through Strombolian eruption and end with lava effusion followed by reworking of smooth tephra on the tuff cone. Eruptive environment and hydrology of vent area in the Udo tuff cone are poorly constrained because the stratigraphic units under the tuff cone are unknown. It is thoughl, however, that the tuff cone could be mainly emergent because the present cone deposits show no evidence of marine reworking, and standing body of sea water could play a great role. The emergent volcano is characterized by distinctive steam-explosivity that results primarily from a bulk interaction between rapidly ascending magma and a highly mobile slurry. The sea water gets into the vent by flooding accross or through the top or breach of tephra cone. Udo tuff cone was constructed from Surtseyan eruption which went into with tephra finger jetting activities in the early stage, late interspersed with continuous uprush activities and proceeded to only continuous uprush activities in the last. When the enclosure of the vent by a long-lived tephra barrier would prevent the flooding and thus allow the vent to dry out, the Surtseyan eruption ceased to transmit into Strombolian activities, which constructed a cinder cone on the crater floor of the tuff cone. The Strombolian eruption ceased when magma in the conduit gradually became depleted in gas. In the case of Udo, the last magmatic activity was Hawaiian-type (and/or fountain) which accumulated basalt lava delta. And then the loose tephra of the tuff cone reworked over the moat lava and the northeastern flank.

• 동굴
• /
• 제21권22호
• /
• pp.17-56
• /
• 1990

Cheju Island, which was formed by volcanic activity, is an oval in its shape with the major axis of 80km and the minor axis of 40km. The island holds in its heart Mt. Hanla rising 1,950m above the sea. Petrological study of this volcanic island has been made actively by Sang-Man Lee, Chong-Kwan won and Moon-Won Lee. The chronological measurements of the island by Chong-Kwan Won and Moon-Won Lee showed that it is composed of Sanbangsan trachytes and Backlokdam trachytes(25,000 year ago). These reports are based on the chemical analysis and the rediometric chronological measurements on the ground. However, there has been no reports about the inside of caves. We made an (composition) analysis of the inside of Manjang Cave by the fundamental parameter method in X-ray fluorescence spectrometry. The fundamental parameter method in X-ray fluorescence spectrometry is nondestructive analysis, and it enables us to make the values processed by a computer. The results obtained by this methods are as follows : SiO$_2$(49％), $Al_2$O$_3$(17％), Fe$_2$O$_3$(13％), CaO(8.1％), MgO(5.5％), Na$_2$O(3.6％), TiO$_2$(2.1％), $K_2$O(0.86％), P$_2$O$_{5}$(0.28％), and MnO(0.20％), respectively. The data obtained by the fundamental parameter method in X-ray fluorescence was compared with the data provided by Chong-Kwan and Moon-Won Lee. Our measurement was made by K-Ar-method in cooperation with T.ITAYA. The samples are of 30,000～420,000 year ago. The composition of the values of our underground analysis with the existing values obtained by the analyses on the ground produced new data about Cheju volcanic island.d.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2008년도 추계 학술발표회
• /
• pp.1630-1637
• /
• 2008

Jeju-do is a island formed by the volcanic activity and has more than 360 volcanic cones distributed widely along the long axis of the elliptically shaped island. The volcanic cones consist mainly of scoria, so called "Song-I" in the local dialect. In this study the chemical and soil mechanical properties of scoria being very different from those of the inland were investigated with the various tests. In the sieve-passing test the particle size of scoria had more than 10 of uniformity coefficient and gradation coefficient of 1 ~ 3, showing relatively homogenous distribution. Based on the uniformity classification, scoria was assorted into GW. In the large scale direct shear tested for measuring the mechanical strength of scoria the internal friction angle of red scoria was $37^{\circ}$ and that of black scoria was $36^{\circ}$. This indicated that there was no difference in the mechanical strength between two types of scoria. On the other hand, red and black scoria had $1.24{\times}10^{-3}$ to $3.55{\times}10^{-2}$ cm/sec of k values for the static water level permeability, thus being classified into a coarse or fine sand as compared with that representing the saturated soil. They also had 1.411 to $1.477\;g/cm^3$ of notably low $r_{dmax}$ values for the compaction test as compared with common soil, which was considered to be due to their low specific gravity and high porosity. In conclusion, the soil mechanic properties of scoria obtained from this study are thought to be very helpful for reducing lots of trial and error happening in the civil engineering construction.

• 자원환경지질
• /
• 제54권2호
• /
• pp.309-309
• /
• 2021

• 한국토양비료학회지
• /
• 제42권6호
• /
• pp.500-512
• /
• 2009

유기물원을 항온 배양했을 때 온도가 토양미생물체량과 효소활성 및 PLFA함량에 미치는 영향을 토양 특성별로 평가하고자 입상과 분상 혼합유기질비료, 돈분퇴비, 음식물퇴비를 화산회토양과 비화산회토양 30g에 2g을 잘 혼합 후 10, 20, $30^{\circ}C$에서 항온배양을 하면서 pH, 토양질소, 유기물 함량, Microbial biomass C와 N, 토양효소활성, 인지질지방산 함량을 분석하였다. 돈분과 음식물퇴비는 토양종류와 온도에 상관없이 토양 pH의 변화가 크지 않았으나 입상유기질비료는 온도가 높을수록 낮아졌으며, 비화산회토양에서 변화폭이 컸다. 미생물체량 C는 화산회토양의 경우 배양 온도가 높고 유기질비료를 처리할 때 높아지는 경향이었지만 토양종류에 상관없이 점차 감소하였다. 미생물체량 N은 비화산회토양에서 유기질비료, 화산회토양에서는 돈분과 음식물퇴비를 처리할 때 높게 나타났다. 인지질 지방산함량은 항온배양 75일후 비화 산회토양이 화산회토양보다 높았고, 270일후 화산회토양에서 높게 나타났으나 점차 낮아지는 경향이었다. Urease활성은 150일에 비화산회토양의 입상유기질비료처리에서 $10^{\circ}C$(75.0)>$20^{\circ}C$(16.3)>$30^{\circ}C$($4.6ug\;NH{_4-}N\;g^{-1}\;2h^{-1}$)순으로 $10^{\circ}C$에서 가장 높게 나타났으며 온도가 높고, 시간이 경과할수록 낮아졌으며 화산회토양의 Urease활성은 $10^{\circ}C$에서 높게 나타났다. ${\beta}-glucosidase$ 활성은 비화산회토양이 화산회토양보다 높았고 시간이 경과할수록 낮아졌다. 토양미생물체량 C와 미생물활성지표간의 상관계수는 비화산회토양에서 PLFA ($r^2=0.91$), 화산회토양에서 ${\beta}-glucosidase$ ($r^2=0.83$)가 높았으며, 미생물활성지표는 토양종류와 온도에 따라 상대적으로 민감도가 다르게 나타났다.

• 수산경영론집
• /
• 제48권3호
• /
• pp.75-90
• /
• 2017

The ocean is used as the term of sea, it is expressed as a large sea. Marine tourism is an activity that takes place in the sea and on the coast. Many experts prospect that the 21st century will be the century of ocean. In recent years, many countries are interested in ocean and marine tourism can be significantly developed in the future. Jeju Island is an island formed by a volcanic eruption, which has a very high landscape value, and It is an oceanic climate with a yearly high temperature due to turbulent flow throughout the years, But Marine tourism is not developed. The purpose of this study is clarify the Marine Tourism activity types, Marine Tourism satisfaction and revisit intention of Chinese Tourists visiting JeJu island. And studies what is the needed activity types of Chinese Marine Tourist in future. This study deals with on the activity types, satisfaction and revisit intention of JeJu Marine Tourism With 252 effective responses gathered from an onsite survey. The statistical analysis of the data was conducted using techniques of frequency analysis, t-test and anova analysis.

• 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.

• Ocean and Polar Research
• /
• 제23권1호
• /
• pp.23-34
• /
• 2001

Geochemical and Sr-Nd isotopic compositions and K-Ar ages are analyzed in volcanic rocks from Weno Island, Caroline Islands. Seven Weno lava samples of alkali basalt and basaltic trachyandesite are aphyric or sparsely phyric comprising olivine, plagioclase, and clinopyroxene phenocrysts. Whole-rock geochemical variation of Weno lavas reflects main fractional crystallization of olivine and Cr-spinel phenocrysts. Newly determined K-Ar ages of Weno lavas range from 6.7 to 11.3 Ma (late Miocene), indicating their formation during primary volcanic stage of Chuuk Islands. Trace element compositions of Weno lavas are very similar to those of typical ocean island basalts (OIBs), suggesting their formation during intra-plate mantle plume activity. The plume composition is isotopically very similar to that of Hawaiian hot spot. However, the age span of Chuuk volcanism is longer than that of the other individual volcanoes in the Pacific.