• The Journal of the Petrological Society of Korea
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• v.28 no.4
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• pp.299-306
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• 2019

We estimated the provenance of the obsidian artifacts from Samgeori site at Yeoncheon, one of the prehistoric sites in South Korea. Pyroxene microlites are of hedenbergite to augite compositions, and intergrown and/or overgrown with Fe-oxides showing poikilitic texture. Major oxides contents for the matrix of the obsidian artifacts exhibit a narrow compositional range, especially SiO₂ contents being 73.0~75.5 wt.% of acidic rhyolitic composition. Also, rare earth element (REE) contents are relatively constant in the obsidian artifacts, and the chondrite-normalized REE patterns show a strong Eu negative anomaly. These mineralogical and geochemical features of the Samgeori obsidian artifacts were compared with those from both the Baekdusan obsidians and Japanese Kyushu obsidians which have been thought to be two major obsidian provenances around South Korea. It is suggested that the Samgeori obsidian artifacts were possibly originated from the Baekdusan obsidians.

• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.243-249
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• 2014

We conducted investigations into the morphological characterstics and chemical compositions of the microlites included in the obsidians from the North Korean side Baekdusan (NK) and in the obsidian artefacts from the Busan Gadeokdo prehistoric site (BG). The morphology of the microlites from the NK can be divided into three groups, and trichite-acicular and trichite-asteroidal types are predominant. On the other hand the microlites from the BG show various morphological features such as acicular, margarite, lath, and asteroidal types. Silicate microlites from the NK are mostly of Ca-pyroxene compositions (hedenbergite to augite), whereas those from the BG are mostly of biotite (annite) with small amount of clinopyroxene (ferrosilite). It is well understood that the microlites from the NK are different from those from the BG in terms of the morphology, mineral content and mineral composition. Thus the obsidian aretefacts from the Busan Gadeokdo prehistoric site seem to have no genetical relationship to the obsidians from the Baekdusan.

• Journal of the Korean earth science society
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• v.28 no.6
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• pp.733-742
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• 2007

Petrological, mineralogical, and geochemical analyses were carried on the paleolithic obsidian implements excavated at Wolseongdong, Daegu, Korea. The obsidians has a homogeneous glassy texture that can be observed in a typical obsidian formed from a rapid cooling of silicic magma. Major element composition of the obsidians represent calc-alkaline series. Comparing those with other obsidians from domestic local excavation sites, Mt. Baekdu, and Kyusu of Japan, the Wolseongdong obsidians show similar element distribution pattern with others in spite of small difference in trace and rare Earth element contents. Sr isotopes of the obsidians considerably differ from those of the obsidians from southern part of the Korean Peninsula or from Mt. Baekdu. K-Ar age is approximately 30 Ma, which is much older than Mt. Baekdu (10 Ma). Therefore, considering the characteristics of obsidians found in the Korean Peninsula including mineralogy, petrology, trace element, and isotopes chronology, the obsidians can be divided into four groups: Mt. Baekdu, southern part of Korea (Kyusu of Japan), middle part of Korea, and Wolseongdong region. These groups suggest a possibility of more than four different origins of the obsidians found in the Korean Peninsular.

• Journal of the Korean earth science society
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• v.38 no.7
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• pp.546-551
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• 2017

We examine the morphology and texture of microlites included in the obsidians from the Baekdusan (Mt. Baekdu) and Kyushu (SW Japan) by using an electron microscope. According to the morphological types of microlites, the microlites in the Baekdusan obsidians are classified as Arculites, Asteroidal and Crenulite, whereas those in the Kyushu obsidians as various types of Arculites, Bacillite, Belonites, Crenulite, Furculite, Lath, Margarite, and Scopulites. Specifically, the Arculites in both obsidians show very distinctive crystal relationships, though they are mainly composed of magnetite and pyroxene. The Baekdusan Arculites exhibit the poikilitic texture of pyroxene crystals enclosing multiple magnetite crystals, whereas the Kyushu ones demonstrate the granular and/or intergranular texture of interlocking between magnetite and pyroxene crystals. This distinction can be used to discriminate the provenance of the obsidian artefacts from the prehistoric sites in the Korean Peninsula.