Palaeomagnetic and rock-magnetic studies of Cretaceous rocks in the Gongju Basin, Korea

Implication of clockwise rotation

Seong-Jae Doh, Wonnyon Kim, Dongwoo Suk, Yong Hee Park, Daekyo Cheong

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Palaeomagnetic and rock-magnetic studies have been carried out for Cretaceous non-marine sedimentary rocks (Gongju Group) and volcanic rocks in the Gongju Basin, located along the northern boundary of the Ogcheon Belt, Korea. K-Ar age dating for the volcanic rocks was also performed. It is found that the Gongju Group was remagnetised during the tilting of the strata with the characteristic remanent magnetisation (ChRM) direction of D / 1 = 23.9° / 50.6° (k = 95.5, α95=3.9°) at 30 per cent untilting of the strata with a maximum value of precision parameter (k), while the volcanic rocks are revealed to acquire primary remanence with the direction of D / 1 = 204.2° / -43.8° (k = 36.6, α95 = 8.6°) after the tilt-correction. The K-Ar ages of the volcanic rocks range from 81.8 ± 2.4 to 73.5 ± 2.2 Ma, corresponding to the Campanian stage of the Late Cretaceous. Electron microscope observations of samples from the Gongju Group show authigenic iron-oxide minerals of various sizes distributed along the cleavage of chlorite and in the pore spaces, indicating that the strata acquired the chemical remanent magnetisation due to the formation of secondary magnetic minerals under the influence of fluids. The palaeomagnetic pole positions are at Lat./Long. = 69.6°N/224.3°E (dp = 3.5°, dm = 5.2°) calculated for the 30 per cent tilt-corrected direction of the Gongju Group and at Lat./Long. = 67.2°N/235.3°E (A95 = 8.9°) for the volcanic rocks. Based on the results of this study, it is interpreted that the volcanic rocks acquired the primary magnetisation almost at the same time as the remagnetisation of the Gongju Group in the Late Cretaceous. Comparisons of Cretaceous palaeomagnetic poles from the Korean Peninsula with those from Eurasia implies that the Korean Peninsula underwent clockwise rotation of 21.2° ± 5.3° for the middle Early Cretaceous, 12.6° ± 5.4° for the late Early Cretaceous, and 7.1° ± 9.8° for the Late Cretaceous with respect to Eurasia, due to the sinistral motion of the Tan-Lu Fault.

Original languageEnglish
Pages (from-to)737-752
Number of pages16
JournalGeophysical Journal International
Volume150
Issue number3
DOIs
Publication statusPublished - 2002 Sep 1

Fingerprint

Volcanic rocks
Korea
Rocks
volcanology
volcanic rock
rocks
Cretaceous
basin
rock
strata
Magnetization
magnetization
peninsulas
remanent magnetization
Poles
tilt
Oxide minerals
poles
Sedimentary rocks
minerals

Keywords

  • Cretaceous
  • Gongju Basin
  • Korea
  • Palaeomagnetism
  • Remagnetisation
  • Rotation

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics

Cite this

Palaeomagnetic and rock-magnetic studies of Cretaceous rocks in the Gongju Basin, Korea : Implication of clockwise rotation. / Doh, Seong-Jae; Kim, Wonnyon; Suk, Dongwoo; Park, Yong Hee; Cheong, Daekyo.

In: Geophysical Journal International, Vol. 150, No. 3, 01.09.2002, p. 737-752.

Research output: Contribution to journalArticle

@article{3b830eddb39d43488603df0bc40176d9,
title = "Palaeomagnetic and rock-magnetic studies of Cretaceous rocks in the Gongju Basin, Korea: Implication of clockwise rotation",
abstract = "Palaeomagnetic and rock-magnetic studies have been carried out for Cretaceous non-marine sedimentary rocks (Gongju Group) and volcanic rocks in the Gongju Basin, located along the northern boundary of the Ogcheon Belt, Korea. K-Ar age dating for the volcanic rocks was also performed. It is found that the Gongju Group was remagnetised during the tilting of the strata with the characteristic remanent magnetisation (ChRM) direction of D / 1 = 23.9° / 50.6° (k = 95.5, α95=3.9°) at 30 per cent untilting of the strata with a maximum value of precision parameter (k), while the volcanic rocks are revealed to acquire primary remanence with the direction of D / 1 = 204.2° / -43.8° (k = 36.6, α95 = 8.6°) after the tilt-correction. The K-Ar ages of the volcanic rocks range from 81.8 ± 2.4 to 73.5 ± 2.2 Ma, corresponding to the Campanian stage of the Late Cretaceous. Electron microscope observations of samples from the Gongju Group show authigenic iron-oxide minerals of various sizes distributed along the cleavage of chlorite and in the pore spaces, indicating that the strata acquired the chemical remanent magnetisation due to the formation of secondary magnetic minerals under the influence of fluids. The palaeomagnetic pole positions are at Lat./Long. = 69.6°N/224.3°E (dp = 3.5°, dm = 5.2°) calculated for the 30 per cent tilt-corrected direction of the Gongju Group and at Lat./Long. = 67.2°N/235.3°E (A95 = 8.9°) for the volcanic rocks. Based on the results of this study, it is interpreted that the volcanic rocks acquired the primary magnetisation almost at the same time as the remagnetisation of the Gongju Group in the Late Cretaceous. Comparisons of Cretaceous palaeomagnetic poles from the Korean Peninsula with those from Eurasia implies that the Korean Peninsula underwent clockwise rotation of 21.2° ± 5.3° for the middle Early Cretaceous, 12.6° ± 5.4° for the late Early Cretaceous, and 7.1° ± 9.8° for the Late Cretaceous with respect to Eurasia, due to the sinistral motion of the Tan-Lu Fault.",
keywords = "Cretaceous, Gongju Basin, Korea, Palaeomagnetism, Remagnetisation, Rotation",
author = "Seong-Jae Doh and Wonnyon Kim and Dongwoo Suk and Park, {Yong Hee} and Daekyo Cheong",
year = "2002",
month = "9",
day = "1",
doi = "10.1046/j.1365-246X.2002.01726.x",
language = "English",
volume = "150",
pages = "737--752",
journal = "Geophysical Journal International",
issn = "0956-540X",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - Palaeomagnetic and rock-magnetic studies of Cretaceous rocks in the Gongju Basin, Korea

T2 - Implication of clockwise rotation

AU - Doh, Seong-Jae

AU - Kim, Wonnyon

AU - Suk, Dongwoo

AU - Park, Yong Hee

AU - Cheong, Daekyo

PY - 2002/9/1

Y1 - 2002/9/1

N2 - Palaeomagnetic and rock-magnetic studies have been carried out for Cretaceous non-marine sedimentary rocks (Gongju Group) and volcanic rocks in the Gongju Basin, located along the northern boundary of the Ogcheon Belt, Korea. K-Ar age dating for the volcanic rocks was also performed. It is found that the Gongju Group was remagnetised during the tilting of the strata with the characteristic remanent magnetisation (ChRM) direction of D / 1 = 23.9° / 50.6° (k = 95.5, α95=3.9°) at 30 per cent untilting of the strata with a maximum value of precision parameter (k), while the volcanic rocks are revealed to acquire primary remanence with the direction of D / 1 = 204.2° / -43.8° (k = 36.6, α95 = 8.6°) after the tilt-correction. The K-Ar ages of the volcanic rocks range from 81.8 ± 2.4 to 73.5 ± 2.2 Ma, corresponding to the Campanian stage of the Late Cretaceous. Electron microscope observations of samples from the Gongju Group show authigenic iron-oxide minerals of various sizes distributed along the cleavage of chlorite and in the pore spaces, indicating that the strata acquired the chemical remanent magnetisation due to the formation of secondary magnetic minerals under the influence of fluids. The palaeomagnetic pole positions are at Lat./Long. = 69.6°N/224.3°E (dp = 3.5°, dm = 5.2°) calculated for the 30 per cent tilt-corrected direction of the Gongju Group and at Lat./Long. = 67.2°N/235.3°E (A95 = 8.9°) for the volcanic rocks. Based on the results of this study, it is interpreted that the volcanic rocks acquired the primary magnetisation almost at the same time as the remagnetisation of the Gongju Group in the Late Cretaceous. Comparisons of Cretaceous palaeomagnetic poles from the Korean Peninsula with those from Eurasia implies that the Korean Peninsula underwent clockwise rotation of 21.2° ± 5.3° for the middle Early Cretaceous, 12.6° ± 5.4° for the late Early Cretaceous, and 7.1° ± 9.8° for the Late Cretaceous with respect to Eurasia, due to the sinistral motion of the Tan-Lu Fault.

AB - Palaeomagnetic and rock-magnetic studies have been carried out for Cretaceous non-marine sedimentary rocks (Gongju Group) and volcanic rocks in the Gongju Basin, located along the northern boundary of the Ogcheon Belt, Korea. K-Ar age dating for the volcanic rocks was also performed. It is found that the Gongju Group was remagnetised during the tilting of the strata with the characteristic remanent magnetisation (ChRM) direction of D / 1 = 23.9° / 50.6° (k = 95.5, α95=3.9°) at 30 per cent untilting of the strata with a maximum value of precision parameter (k), while the volcanic rocks are revealed to acquire primary remanence with the direction of D / 1 = 204.2° / -43.8° (k = 36.6, α95 = 8.6°) after the tilt-correction. The K-Ar ages of the volcanic rocks range from 81.8 ± 2.4 to 73.5 ± 2.2 Ma, corresponding to the Campanian stage of the Late Cretaceous. Electron microscope observations of samples from the Gongju Group show authigenic iron-oxide minerals of various sizes distributed along the cleavage of chlorite and in the pore spaces, indicating that the strata acquired the chemical remanent magnetisation due to the formation of secondary magnetic minerals under the influence of fluids. The palaeomagnetic pole positions are at Lat./Long. = 69.6°N/224.3°E (dp = 3.5°, dm = 5.2°) calculated for the 30 per cent tilt-corrected direction of the Gongju Group and at Lat./Long. = 67.2°N/235.3°E (A95 = 8.9°) for the volcanic rocks. Based on the results of this study, it is interpreted that the volcanic rocks acquired the primary magnetisation almost at the same time as the remagnetisation of the Gongju Group in the Late Cretaceous. Comparisons of Cretaceous palaeomagnetic poles from the Korean Peninsula with those from Eurasia implies that the Korean Peninsula underwent clockwise rotation of 21.2° ± 5.3° for the middle Early Cretaceous, 12.6° ± 5.4° for the late Early Cretaceous, and 7.1° ± 9.8° for the Late Cretaceous with respect to Eurasia, due to the sinistral motion of the Tan-Lu Fault.

KW - Cretaceous

KW - Gongju Basin

KW - Korea

KW - Palaeomagnetism

KW - Remagnetisation

KW - Rotation

UR - http://www.scopus.com/inward/record.url?scp=0036713487&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036713487&partnerID=8YFLogxK

U2 - 10.1046/j.1365-246X.2002.01726.x

DO - 10.1046/j.1365-246X.2002.01726.x

M3 - Article

VL - 150

SP - 737

EP - 752

JO - Geophysical Journal International

JF - Geophysical Journal International

SN - 0956-540X

IS - 3

ER -