• Korean Journal of Mineralogy and Petrology
• /
• v.36 no.4
• /
• pp.365-376
• /
• 2023

Songaksan, formed about 3800 year ago, is one of the tuff rings in the Jeju Island. Mantle xenoliths, spinel peridotites, are enclosed in the Songaksan Trachybasalt. The spinel peridotites are less than 2 cm in size and are composed of olivine, orthopyroxene, clinopyroxene, and spinel. The uniform compositions of the minerals from core to rim indicate that equilibrium was reached in the spinel peridotites before these were enclosed in the host magma. The spinel peridotites originated at depths between 55 and 60 km with equilibrium temperatures ranging from 915 to 968℃. The spinel peridotites from Songaksan reveal porphyroclastic texture with a lot of neoblast minerals. Olivines display strong kink banding, indicating that the upper mantle of Songaksan has been deformed. The spinel peridotites from Songaksan have undergone about 5~7% fractional melting, and cryptic metasomatism by an silicate melt. The period of entrainment and transport of the spinel peridotites in the host magma is about 15 days.

• Journal of architectural history
• /
• v.30 no.3
• /
• pp.55-66
• /
• 2021

The purpose of this study is to review the research on Gangbang Palace and to presume the location of the palace through the study of feng shui. when the Mongols invaded, Ganghwado was the capital, moved from Gaegyeong and it was maintained for 39 years. At that time, the palace construction followed the palace of Gaegyeong, and the names such as Gujeong毬庭, Palace, and Sasa寺社 were the same as those of Gaegyeong. However, despite several archaeological excavations at Goryeo Palace Site, Historic Site No. 133, no actual remains of the Goryeo period were found. After the negative opinions on the current Goryeo Palace site became public, there have been several previous studies on the estimation of the location of the Goryeo Palace Site, and although there have been achievements, the location of the Goryeo Palace is still not confirmed. The key to presuming the location of the GangdoPalace江都宮闕 is first, whether the palace was located in the south of Songaksan, and second, at what point it was located in the south of Songaksan. As to whether the palace was located in the south of Songaksan, it was presumed that the Chiso治所 of Ganghwabu was located in Gukhwari, referring to the record in 『Shinjeungdongguknyeojiseungnam新增東國輿地勝覽』 that Goryeosan, a guardian mountain鎭山, was 'five ri west of Bu府西五里'. Accordingly, the location of the palace of 'Budongsimni 府東十里' in the old literature was estimated to be south of Songaksan Mountain. Also, the location of the palace on the south side of Songaksan was approached from a feng shui theory. Three places for the palace to be located are presumed to be 'Ganghwa Girls' High School', 'Seonggwang Church', or 'Above the Ganghwa-gun library', and the central axis of the palace is estimated to be 'Above the Ganghwa-gun library' where the corridor-type building relics were found among them, and the other two areas were presumed to be other buildings within the palace.

• The Journal of the Petrological Society of Korea
• /
• v.10 no.1
• /
• pp.13-26
• /
• 2001

Songaksan volcano, which occurs as a monogenetic volcano on the southwestern promontory of Hallasan shield volcano, is composed of tuff ring, cinder cone, lava pond and cinder conelet complex on wide basalt plateau. Except for an influx of external quartz xenocrysts in the tuff ring. Totally the volcano ranges from trachyandesite to trachybasalt in petrography and chemical compositions, which confirm the continuum between the evolved and primitive compositions widely occurring in the Jeju volcanic system. Chemical data for the volcano show quantitative compositional variation from the lower to the upper part of the volcanic sequences. The continuous compositional variations generally define a compositionally zoned magma storage. The chemical data suggest that the compositiona1 donations might have resulted from the fractional crystallization of a parental alkali magma. As result, the Songaksan volcano initially tapped the lop of the zoned magma storage and subsequently erupted successively more primitive magma.

• Journal of the Korean earth science society
• /
• v.27 no.2
• /
• pp.236-246
• /
• 2006

On the basis of field observation, geology of the footprints site consists of the Kwanghaeak Basalt, unnamed strata, Songaksan Tuff, Hamori Formation, and Sand Dune, in ascending order at the Hamori-Songaksan area and the Kwanghaeak Basalt, the hominid footprints-bearing strata, and Dune Sand are consisted in ascending order at the Sagaeri area. According to the designation that the Hamori Formation overlies the Songaksan Tuff, age dating results, and geologic sequence observed in the field, the strata containing hominid footprints are not correlated with the Hamori Formation but the unnamed strata, though the strata are shown as the Hamori Formation in the geologic map. It seems to be more reasonable that the geologic age of the footprints-bearing strata is thought to be around ca 15,000 yrs B.P. according to the results of $^{14}C$ dating.

• The Journal of the Petrological Society of Korea
• /
• v.25 no.1
• /
• pp.69-83
• /
• 2016

Radiocarbon and OSL ages of three monogenetic volcanoes inferred to be the last volcanoes on Jeju Island, Korea were determined to identify a volcano described in historical records. The results show that the ages of those volcanoes are roughly <3.8 ka (Songaksan), >4.5 ka (Biyangdo), and <6~7 ka (Ilchulbong). Though our efforts to make a positive match between historical records and volcano-chronological dating were not successful, we make a new suggestion in this paper that two historical records of volcanic activity in 1002 and 1007 A.D. could be interpreted to be the sequential volcanic events from a single monogenetic volcano. In addition, based on a volcanological reinterpretation of historical records, we infer that the volcano described therein is most likely Mt. Songaksan, in Daejeongeup, which had early phreatomagmatic and late magmatic activities after 3.8 ka ago. Furthermore, considering the geopolitical relationship between the Goryeo Dynasty and the Tamna Kingdom, in addition with the culture of the era, this study sheds new light on the possibility that there is a time gap between the actual eruptions and the historical recording of them by ancient people.

• Journal of the Korean earth science society
• /
• v.24 no.3
• /
• pp.172-180
• /
• 2003

Geologic field survey is very important for the high school students who take the courses of earth science under the 7th earth science curriculum, however actually it is very difficult for the students to survey in the field because of long time and distance, and expenses. To overcome these difficulties, this study focused on developing the web contents and teaching-learning materials for virtual geologic field survey of the Songaksan and Jisagae area, Jeju island. The developed web contents were placed into three parts; main manu, sub manu and contents to help the learners flow-chart of the program easily. To overcome the weakness of existing textual web materials, some movable images and worksheets were provided for the learners, and the web contents were designed for the learners to experience as similar as the geologic field survey may let them do.

• Animal Systematics, Evolution and Diversity
• /
• v.26 no.1
• /
• pp.83-86
• /
• 2010

A new species of the family Thorectidae, Narrabeena nigra n. sp. is described. This species was collected from the front of Songaksan, Daejeong-eup, Seogwipo-si, Jejudo Island, Korea. Narrabeena nigra n. sp. is similar to Narrabeena lamellate (Bergquist, 1980) with uncored primary and secondary fibres and an unarmoured surface. They differ in growth form, colour, and fibres.

• The Journal of the Petrological Society of Korea
• /
• v.25 no.2
• /
• pp.143-149
• /
• 2016

Eruptive volumes of three monogenetic volcanoes (Songaksan tuff ring, Biyangdo scoria cone, and Ilchulbong tuff cone) with the youngest eruption age are calculated using the model, applied to Auckland Volcanic Field in New Zealand, to investigate the volcanic eruption scale and to evaluate volcanic hazard of Jeju Island. Calculated eruptive volumes of the volcanoes are $24,987,557m^3$, $9,652,025m^3$, and $11,911,534m^3$, respectively, and the volumes include crater infill, tuff ring (tuff cone), scoria cone, and lava flow. Volcanic explosivity indices of Songaksan tuff ring, Biyangdo scoria cone, and Ilchulbong tuff cone are estimated based on the eruptive volumes to be 3, 2, and 3 respectively, and eruption type is Strombolian to Surtseyan. It is assumed that the amount of emitted sulfur dioxide gas is $2-8{\times}10^3kt/y$ according to the correlation between volcanic explosivity index and volcanic sulfur dioxide index. Recent age dating researches reveal evidences of several volcanic activities during the last 10,000 years indicating the possible volcanic eruption in Jeju Island in the near future. Therefore, it is necessary for appropriate researches regarding volcanic eruption of the island to be accomplished. In addition, establishment of the evaluation and preparation system for volcanic hazard based on the researches is required.

• Economic and Environmental Geology
• /
• v.54 no.2
• /
• pp.187-197
• /
• 2021

The Hyeongjeseom (Islet) is an erosional remnant of volcano which is located about 2 km northeast of sea shore of the Songaksan tuff ring, and is composed of volcaniclastic deposit, agglomerate and scoria deposit, ponded lava, aa lava flows, reworked deposit and beach deposit in ascending order from the base. The volcano is formed by volcaniclastic deposits and lava flows that recorded a transition from initial phreatomagmatic to magmatic explosions followed by lava effusion. It is interpreted that the outcropped volcaniclastic deposit may be a remaining portion of outer ring of a tuff cone. A bomb and a ponded lava yield geochemically basaltic trachyandesite compositions (SiO2 51.3 wt%, Na2O+K2O 6.0 wt%) and belong to olivine basalt with scarce (<5 %) phenocrysts of olivine, petrographically. By incremental heating Ar-Ar dating method, the plateau age of lava flow in the Heongjesom is 9.2±3.6(2σ) ka, implying that the volcanism of Heongjeseom may have occurred earlier than the Songaksan tuff ring which erupted ca. 3.7 ka. It still remains a task to find a volcano which matches with a historical record of volcanic activity that occurred a thousand years ago.

• Microbiology and Biotechnology Letters
• /
• v.41 no.4
• /
• pp.383-390
• /
• 2013

Several yeasts were isolated from flowers found in Gyonggi-do Province and Jeju island in Korea. They were then identified by a comparison of their PCR-amplified D1/D2 regions of 26S rDNA, internal transcribed spacer 1 and 2 inclusive of 5.8S rDNA, using the BLAST database. A total of fifty four yeast strains were isolated from wild flowers in Gyonggi-do and the genus Pseudozyma was noted as being dominant. A total of thirty two strains were isolated from Songaksan and Seongsan-ilchulbong in Jeju island and Sporobolomyces ruberrimus was seen to be dominant. The anti-gout xanthine oxidase inhibitory activities of the culture broths and cell-free extracts from eighty six yeast strains were then determined. The cell-free extracts of Pseudozyma hubeiensis 228-S-1 exhibited the highest xanthine oxidase inhibitory activity of 19.6%. The XOD inhibitor was also maximally produced when Pseudozyma hubeiensis 228-S-1 was cultured at $30^{\circ}C$ for 36h in YEPD medium.