• The Journal of the Petrological Society of Korea
• /
• v.21 no.2
• /
• pp.89-112
• /
• 2012

The Korean Peninsula consists of three Precambrian blocks: Nangrim, Gyeonggi and Yeongnam massifs. Here we revisited previous stratigraphic relationships, largely based on new geochronologic data, and investigated the crustal evolution history of the Precambrian massifs. The Precambrian strata have been usually divided into lower crystalline basements and upper supracrustal rocks. The former has been considered as Archean or Paleoproterozoic in age, whereas the latter as Paleoproterozoic or later. However, both are revealed as the Paleoproterozoic (2.3-1.8 Ga) strata as a whole, and Archean strata are very limited in the Korean Peninsula. These make the previous stratigraphic system wrong and require reconsideration. The oldest age of the basement rocks can be dated as old as Paleoarchean, suggested by the occurrence of ~3.6 Ga inherited zircon. However, most of crust-forming materials were extracted from mantle around ~2.7 Ga, and produced major portions of crust materials at ~2.5 Ga, which make each massif a discrete continental mass. After that, all the massifs belonged to continental margin orogen during the Paleoproterozoic time, and experienced repeated intracrustal differentiation. After the final cratonization occurring at ~1.9-1.8 Ga, they were stabilized as continental platforms. The Nangrim and Gyeonggi massif included local sedimentary deposition as well as igneous activity during Meso-to Neoproterozoic, but the Yeongnam massif remained stable before the development of Paleozoic basin.

• The Journal of the Petrological Society of Korea
• /
• v.5 no.1
• /
• pp.10-20
• /
• 1996

The increament of crustal thickness, continental growth and evolution, plate tectonic movements, and mega-impacts of meteorites have been worldwidely studied in the subdivision of Precambrian. In many subdivision methods of Precambrian Eon and Eonthem, the division based on the principle of the Plate tctonic movement referred internationally, is as follows, $L^AT_EX$ The rationality of this subdivision and some problems in the currently adopted stratigraphic subdivision of Precambrian Eonthem will by commented, and the validity of English and Korean Geological terminology on the Precambrian stratigraphy of northeastern Asia will be discussed also.

• Proceedings of the Petrological Society of Korea Conference
• /
• 1998.09a
• /
• pp.33-33
• /
• 1998

• Proceedings of the Mineralogical Society of Korea Conference
• /
• 2002.05a
• /
• pp.31-33
• /
• 2002

• Proceedings of the Petrological Society of Korea Conference
• /
• 2009.05a
• /
• pp.170-174
• /
• 2009

• The Journal of the Petrological Society of Korea
• /
• v.18 no.2
• /
• pp.171-179
• /
• 2009

LA-ICP-MS U-Pb zircon age was determined from the granite gneiss from Jeungsan-Pyeongwon area located to the west of Pyeongan Basin, North Korea, yielding concordant age of $1,873{\pm}19(2{\sigma})$Ma interpreted as Paleoproterozoic granitic magmatism. Considering relatively precise data reported recently using SHRIMP and LA-ICP-MS, ages around 1,870 Ma have been most frequently reported from Precambrian basement rocks of Korean peninsula, including Yeongnam, Gyeonggi, and Nangnim massifs altogether. Geologic events of this period are interpreted as not only granitic magmatism but also hightemperature regional metamorphism depending on their localities. The magmatic and regional metamorphic events of similar periods have also been reported from neighboring cratons of both North China and South China. Therefore, we need more data and efforts to decipher correlation between Precambrian basements between Korea and China.

• Proceedings of the KSEEG Conference
• /
• 2002.04a
• /
• pp.283-285
• /
• 2002

• The Journal of the Petrological Society of Korea
• /
• v.14 no.3 s.41
• /
• pp.141-148
• /
• 2005

Lead isotopic compositions are analyzed from the sulfide minerals of the Yeonhwa, Janggun and Uljin deposits and from host limestone, intrusives, and basement rocks to reveal the source of Pb in these deposits. In the $^{206}Pb/^{204}Pb$ vs $^{207}Pb/^{204}Pb$ plot, Galenas from the Yeonhwa mine display relatively well defined positive linear array, similar to the Precambrian basement rocks of the Korean peninsula. A galena sample from the Uljin mine, Janggun limestone and the basement rocks also follow the variation of Yeonhwa mine. However, ore minerals from the Janggun mine, having relatively low $^{206}Pb/^{204}Pb$ values, reveal offset from such trend toward lower $^{207}Pb/^{204}Pb$ values. Considering the fact that Mesozoic igneous rocks and ores within the Gyeongsang basin display considerably lower $^{207}Pb/^{204}Pb$ values than basement rocks of the Korean peninsula, the deviation of Janggun ore minerals can be interpreted as to reflect mixing between leads from old continental crustal materials and from Mesozoic igneous rocks with more mantle signature. The lead of the Yeonhwa and Uljin mine, following trend of Precambrian basement rather well, seems to have been originated mostly from such basement. However, regarding that they occupy low $^{207}Pb/^{204}Pb$ side of the variation trend of the basement, the possibility of having some leads derived from the Mesozoic igneous rocks cannot be excluded.

• Economic and Environmental Geology
• /
• v.22 no.3
• /
• pp.293-300
• /
• 1989

The basal metamorphic complex of the central Sobaegsan Massif consists of pelitic & psammitic paragneisses, various kinds of granitic gneisses and lesser amounts of amphibolite. The granitic gneisses could be clearly distinguished from the pelitic and psammitic paragneisses on the basis of major-element geochemistry. A number of geochemical plots reveals that granitic gneisses were derived from calc - alkaline igneous rocks.

• The Journal of the Petrological Society of Korea
• /
• v.5 no.2
• /
• pp.168-187
• /
• 1996

In the study area Uanggunbong-Samgunri area), Precambrian metamorphic complex, (Taebacksan gneiss complex, Hyundong gneiss complex, and Taebacksan schist complex) had undergone three different regional metamorphisms at least before Paleozoic. The Paleozoic sediments in the study area also had undergone three different metamorphisms at least. The first is low pressure type regional metamorphism, the second is low pressure type contact metamorphism due to the intrusion of Chunyang granite, and the last is medium pressure type metamorphism caused by thrust in south of Janggunbong area. The first metamorphism formed the prevailing metamorphic zones in the Paleozoic metasediments and the metamorphic grade of the first regional metamorphism increases from the chloritoid zone, through the staurolite zone, garnet zone, staurolite+biotite zone, and to the andalusite+biotite zone. The second metamorphism affected both Pre-Cambrian and Paleozoic metasediments located close to the Chunyang granite. The effect of the contact metamorphism is restricted to the very narrow zone around the granite. The third metamorphism that produced kyanite, is restricted to the very narrow region near the thrust fault in the south of Janggunbong with an E-W trend.