Verification of Genetic Process for the High-purity Limestone in Daegi Formation by Oxygen-carbon Stable Isotope Characteristics

Chang Seong Kim, Seon-Gyu Choi, Gyu Bo Kim, Jeonggeuk Kang, Sang Tae Kim, Jonghyun Lee, Jaeho Jang

Research output: Contribution to journalArticle

Abstract

Two assertions about the process the formation of the high-purity limestone in the Taebaeksan Basin, categorized into syngenetic and epigenetic origin, are verified on the basis of its oxygen-carbon stable isotopic characteristics. The carbonate rocks sampled from the selective six high-purity limestone mines and several outcrops in the Daegi formation are featured by various colors such as the gray, light gray and dark gray. They show a wide range of oxygen stable isotope ratios (4.5 ~ 21.6 ), but a narrow range of carbon stable isotope ratios (-1.1 ~ 0.8 , except for vein calcite), which means that they had not experienced strong hydrothermal alteration. In addition, there is no difference in the range of the oxygen stable isotope ratios by mine and color, and it is similar to the range from surrounding outcrop samples. These results indicate that the effect of the hydrothermal alteration were negligible in the generation of high-purity limestone in deposit scale. Whereas, the carbonate rocks can be divided texturally into two groups on the basis of an oxygen isotope ratio; the massive-textured or well-layered samples (>15 ), and the layer-disturbed (or layer-destructed) and showing over two colors in one sample (<15 ). In the multi-colored samples, the bright parts are characterized by the very low oxygen stable isotope ratios, compared to the dark parts, implying the increase in brightness of the carbonate rocks could be induced by the interaction between hydrothermal fluid and rock. However, these can be applied in a small scale such as one sample and are not suitable for interpretation of the generation of high-purity limestone as a deposit scale. In particular, the high oxygen isotope ratios from the recrystallized white limestone suggest that hydrothermal fluids are also rarely involved during recrystallization process. In addition, the occurrences of the high-purity limestone orebody strongly support the high-purity limestone in the area are syngenetic rather than epigenetic; the high-purity limestone layers in the area show continuous and almost horizontal shapes, and is intercalated between dolomite layers. Consequently, the overall reinterpretation based on the sequential stratigraphy over the Taebaeksan basin would play an important role to find additional reserves of the high-purity limestone.

Original languageEnglish
Pages (from-to)107-118
Number of pages12
JournalEconomic and Environmental Geology
Volume52
Issue number1
DOIs
Publication statusPublished - 2019 Jan 1

Keywords

  • Carbonate factory
  • Daegi Formation
  • High-purity limestone
  • Oxygen-carbon stable isotope
  • Taebaeksan Basin

ASJC Scopus subject areas

  • Environmental Science (miscellaneous)
  • Geology
  • Economic Geology

Fingerprint Dive into the research topics of 'Verification of Genetic Process for the High-purity Limestone in Daegi Formation by Oxygen-carbon Stable Isotope Characteristics'. Together they form a unique fingerprint.

  • Cite this