Characteristics of Jurassic continental arc magmatism in South Korea

Tectonic implications

Weon Seo Kee, Sung Won Kim, Youn Joong Jeong, Sanghoon Kwon

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Study of whole-rock geochemical and isotope (Sr-Nd) characteristics of Jurassic plutons from South Korea shows differences in chemical compositions that might reflect the Jurassic tectonic environments of East Asia. These plutons are dominated by granites and granodiorites with subordinate intermediate monzodiorite to diorite phases. All analyzed samples show depletions in Ta-Nb, P, and Ti and enrichment in large ion lithophile elements, characteristic of high-K calc-alkaline I-type granitoids of the active continental margin. Early Jurassic plutons fall into two groups: 87Sr/86Sr I = 0.708730-0.716792, ε Nd(T) =-19.6 to-9.4, from the middle of the Yeongnam Massif (i.e., Beonam, Geochang, and Gimcheon), and 87Sr/86Sr I = 0.704794-0.706967, ε Nd(T) =-6.3 to 0.9, in the southeastern end of the Yeongnam Massif (i.e., Chilgok and Hapcheon). Foliated leucogranite, foliated K-feldspar megacryst-bearing granodiorite, and massive biotite granite of the Early Jurassic Beonam pluton have SHRIMP zircon U-Pb ages of 196, 191, and 190 Ma, respectively. Middle Jurassic plutons of the Okcheon Belt (i.e., in the Iksan, Jeonju, and Sunchang areas) have high 87Sr/86Sr I ratios (0.710453-0.717192) and strongly negative ε Nd(T) values (-20.8 to-13.9). These differences suggest that paleo-Pacific plate subduction along the continental outmost margin during the Early Jurassic gave rise to Andean-type magmatism, represented by minor crustal thickening and subsequent lithospheric delamination. This resulted in the upwelling of asthenospheric mantle and formation of juvenile crust by underplating of mantle-derived magma in the lower crust (e.g., Chilgok and Hapcheon plutons). A subsequent underplating and heating event from the asthenosphere partially melted the overlying preexisting underplated mafic rocks and ancient crust, leading to the formation of Early Jurassic plutons (e.g., Beonam, Geochang, and Gimcheon) and Middle Jurassic plutons that are preserved more inlandward within the Korean Peninsula.

Original languageEnglish
Pages (from-to)305-323
Number of pages19
JournalJournal of Geology
Volume118
Issue number3
DOIs
Publication statusPublished - 2010 May 1

Fingerprint

continental arc
pluton
magmatism
Jurassic
tectonics
underplating
granodiorite
continental margin
megacryst
crust
mantle
leucogranite
crustal thickening
delamination
Pacific plate
asthenosphere
diorite
mafic rock
lower crust
feldspar

All Science Journal Classification (ASJC) codes

  • Geology

Cite this

Kee, Weon Seo ; Kim, Sung Won ; Jeong, Youn Joong ; Kwon, Sanghoon. / Characteristics of Jurassic continental arc magmatism in South Korea : Tectonic implications. In: Journal of Geology. 2010 ; Vol. 118, No. 3. pp. 305-323.
@article{cab4feed14404436a79a38ab4054770f,
title = "Characteristics of Jurassic continental arc magmatism in South Korea: Tectonic implications",
abstract = "Study of whole-rock geochemical and isotope (Sr-Nd) characteristics of Jurassic plutons from South Korea shows differences in chemical compositions that might reflect the Jurassic tectonic environments of East Asia. These plutons are dominated by granites and granodiorites with subordinate intermediate monzodiorite to diorite phases. All analyzed samples show depletions in Ta-Nb, P, and Ti and enrichment in large ion lithophile elements, characteristic of high-K calc-alkaline I-type granitoids of the active continental margin. Early Jurassic plutons fall into two groups: 87Sr/86Sr I = 0.708730-0.716792, ε Nd(T) =-19.6 to-9.4, from the middle of the Yeongnam Massif (i.e., Beonam, Geochang, and Gimcheon), and 87Sr/86Sr I = 0.704794-0.706967, ε Nd(T) =-6.3 to 0.9, in the southeastern end of the Yeongnam Massif (i.e., Chilgok and Hapcheon). Foliated leucogranite, foliated K-feldspar megacryst-bearing granodiorite, and massive biotite granite of the Early Jurassic Beonam pluton have SHRIMP zircon U-Pb ages of 196, 191, and 190 Ma, respectively. Middle Jurassic plutons of the Okcheon Belt (i.e., in the Iksan, Jeonju, and Sunchang areas) have high 87Sr/86Sr I ratios (0.710453-0.717192) and strongly negative ε Nd(T) values (-20.8 to-13.9). These differences suggest that paleo-Pacific plate subduction along the continental outmost margin during the Early Jurassic gave rise to Andean-type magmatism, represented by minor crustal thickening and subsequent lithospheric delamination. This resulted in the upwelling of asthenospheric mantle and formation of juvenile crust by underplating of mantle-derived magma in the lower crust (e.g., Chilgok and Hapcheon plutons). A subsequent underplating and heating event from the asthenosphere partially melted the overlying preexisting underplated mafic rocks and ancient crust, leading to the formation of Early Jurassic plutons (e.g., Beonam, Geochang, and Gimcheon) and Middle Jurassic plutons that are preserved more inlandward within the Korean Peninsula.",
author = "Kee, {Weon Seo} and Kim, {Sung Won} and Jeong, {Youn Joong} and Sanghoon Kwon",
year = "2010",
month = "5",
day = "1",
doi = "10.1086/651503",
language = "English",
volume = "118",
pages = "305--323",
journal = "Journal of Geology",
issn = "0022-1376",
publisher = "University of Chicago",
number = "3",

}

Characteristics of Jurassic continental arc magmatism in South Korea : Tectonic implications. / Kee, Weon Seo; Kim, Sung Won; Jeong, Youn Joong; Kwon, Sanghoon.

In: Journal of Geology, Vol. 118, No. 3, 01.05.2010, p. 305-323.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Characteristics of Jurassic continental arc magmatism in South Korea

T2 - Tectonic implications

AU - Kee, Weon Seo

AU - Kim, Sung Won

AU - Jeong, Youn Joong

AU - Kwon, Sanghoon

PY - 2010/5/1

Y1 - 2010/5/1

N2 - Study of whole-rock geochemical and isotope (Sr-Nd) characteristics of Jurassic plutons from South Korea shows differences in chemical compositions that might reflect the Jurassic tectonic environments of East Asia. These plutons are dominated by granites and granodiorites with subordinate intermediate monzodiorite to diorite phases. All analyzed samples show depletions in Ta-Nb, P, and Ti and enrichment in large ion lithophile elements, characteristic of high-K calc-alkaline I-type granitoids of the active continental margin. Early Jurassic plutons fall into two groups: 87Sr/86Sr I = 0.708730-0.716792, ε Nd(T) =-19.6 to-9.4, from the middle of the Yeongnam Massif (i.e., Beonam, Geochang, and Gimcheon), and 87Sr/86Sr I = 0.704794-0.706967, ε Nd(T) =-6.3 to 0.9, in the southeastern end of the Yeongnam Massif (i.e., Chilgok and Hapcheon). Foliated leucogranite, foliated K-feldspar megacryst-bearing granodiorite, and massive biotite granite of the Early Jurassic Beonam pluton have SHRIMP zircon U-Pb ages of 196, 191, and 190 Ma, respectively. Middle Jurassic plutons of the Okcheon Belt (i.e., in the Iksan, Jeonju, and Sunchang areas) have high 87Sr/86Sr I ratios (0.710453-0.717192) and strongly negative ε Nd(T) values (-20.8 to-13.9). These differences suggest that paleo-Pacific plate subduction along the continental outmost margin during the Early Jurassic gave rise to Andean-type magmatism, represented by minor crustal thickening and subsequent lithospheric delamination. This resulted in the upwelling of asthenospheric mantle and formation of juvenile crust by underplating of mantle-derived magma in the lower crust (e.g., Chilgok and Hapcheon plutons). A subsequent underplating and heating event from the asthenosphere partially melted the overlying preexisting underplated mafic rocks and ancient crust, leading to the formation of Early Jurassic plutons (e.g., Beonam, Geochang, and Gimcheon) and Middle Jurassic plutons that are preserved more inlandward within the Korean Peninsula.

AB - Study of whole-rock geochemical and isotope (Sr-Nd) characteristics of Jurassic plutons from South Korea shows differences in chemical compositions that might reflect the Jurassic tectonic environments of East Asia. These plutons are dominated by granites and granodiorites with subordinate intermediate monzodiorite to diorite phases. All analyzed samples show depletions in Ta-Nb, P, and Ti and enrichment in large ion lithophile elements, characteristic of high-K calc-alkaline I-type granitoids of the active continental margin. Early Jurassic plutons fall into two groups: 87Sr/86Sr I = 0.708730-0.716792, ε Nd(T) =-19.6 to-9.4, from the middle of the Yeongnam Massif (i.e., Beonam, Geochang, and Gimcheon), and 87Sr/86Sr I = 0.704794-0.706967, ε Nd(T) =-6.3 to 0.9, in the southeastern end of the Yeongnam Massif (i.e., Chilgok and Hapcheon). Foliated leucogranite, foliated K-feldspar megacryst-bearing granodiorite, and massive biotite granite of the Early Jurassic Beonam pluton have SHRIMP zircon U-Pb ages of 196, 191, and 190 Ma, respectively. Middle Jurassic plutons of the Okcheon Belt (i.e., in the Iksan, Jeonju, and Sunchang areas) have high 87Sr/86Sr I ratios (0.710453-0.717192) and strongly negative ε Nd(T) values (-20.8 to-13.9). These differences suggest that paleo-Pacific plate subduction along the continental outmost margin during the Early Jurassic gave rise to Andean-type magmatism, represented by minor crustal thickening and subsequent lithospheric delamination. This resulted in the upwelling of asthenospheric mantle and formation of juvenile crust by underplating of mantle-derived magma in the lower crust (e.g., Chilgok and Hapcheon plutons). A subsequent underplating and heating event from the asthenosphere partially melted the overlying preexisting underplated mafic rocks and ancient crust, leading to the formation of Early Jurassic plutons (e.g., Beonam, Geochang, and Gimcheon) and Middle Jurassic plutons that are preserved more inlandward within the Korean Peninsula.

UR - http://www.scopus.com/inward/record.url?scp=77951428777&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77951428777&partnerID=8YFLogxK

U2 - 10.1086/651503

DO - 10.1086/651503

M3 - Article

VL - 118

SP - 305

EP - 323

JO - Journal of Geology

JF - Journal of Geology

SN - 0022-1376

IS - 3

ER -