Journal of the Korean Geographical Society (대한지리학회지)

The Korean Geographical Society (대한지리학회)
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Application of In-situ Produced Cosmogonic $^{10}$ Be and $^{26}$ Al for Estimating Erosion Rate and Exposure Age of Tor and Block Stream Detritus: Case Study from Mt. Maneo, South Korea

우주기원 방사성 핵종을 이용한 만어산 암설지형의 침식률 및 노출연대 측정

  • Yeong Bae Seong (Dept. of Geography Education, Seoul National University) ;
  • Jong Wook Kim (Dept. of Geography Education, Seoul National University)
  • Published : 2003.06.01
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Abstract

CRN (Cosmogenic radionuclide) methodology has been a versatile tool applicable to a wide range of geomorphology. This study was underiaken to ascertain the rate of erosion and exposure age of mountain-top detritus (tors and block streams) on Mt. Maneo by employing the concentrations of in-situ produced cosmogenic $^{10}$ Be and $^{26}$ Al from bedrock surfaces that are exposed to cosmic rays. The results suggest that tors on the summit were positioned here during the glacial period but no later than 65ka and block streams have been stabilized also since the last glacial period but no later than 38ka. The tors on the summit have been eroded at a slower rate (9m/Ma) than blocks on the hillslope (15m/Ma) since the initial abrupt exposure of each landform to cosmic rays, suggesting that there is a slight difference in the rate of erosion between the summit and the hillslope, and that the local relief between the two areas has been increased. When the $^{26}$ Al/$^{10}$ Be-$^{10}$ Be concentrations from samples are plotted in Lal's steady-state erosion island, one sample (from a for) has complex exposure histories, which can be explained by the occurrence of multiple chipping event of 5cm to 60cm in length on the surface of the rock.

우주 기원의 방사성 핵종(核種)은 근래에 지형연구에 널리 활용되고 있다. 본 연구에서는 우주 기원의 방사성 핵종인 $^{10}$ Be과 $^{26}$ Al를 이용하여 만어산의 토르와 암괴류를 대상으로 그 구성 암석의 지표 노출 연대와 침식률을 측정하였다. 연구 결과, 토르는 적어도 약 6만 5천년 전, 그리고 암괴류는 적어도 3만 8천년 전에 노출된 것으로 나타났다. 한편, 토르와 암괴류의 구성 암석의 표면 침식률은 각각 9m/Ma 15m/Ma인 것으로 나타났다. 이러한 침식률의 차이는 풍화 및 침식에 대한 국지적인 조건이 다르기 때문인 것으로 생각된다. 특이한 점은, 산정부에 위치한 토르의 구성 암석들 중 일부가 $^{26}$ Al/$^{10}$ Be과 $^{10}$ Be를 이용하는 Lal (1991)이 밝힌 정상상태 침식구역(steady-state erosion island)에서 벗어나 있는데 이것은 이 토르의 표면이 비정상적인 침식의 경로를 겪었다는 것을 의미하며 본 연구에서는5cm-60cm 정도의 표면이 여러 번 떨어져 나갔다는 것으로 판단된다.

Keywords

References

  1. Permafrost and Periglacial Processes v.9 Age and significance of mountain-top detritus Ballantyne,C.K. https://doi.org/10.1002/(SICI)1099-1530(199810/12)9:4<327::AID-PPP298>3.0.CO;2-9
  2. Geomorphology v.27 Mid-southwestern Minnesota and southern Baffin Island: a multiple approach Bierman,P.R.;Marsella,K.A.;Patterson,C.;Davis,P.T.;Caffe,M. https://doi.org/10.1016/S0169-555X(98)00088-9
  3. Journal of Geophysical Research v.99 no.B7 Using in situ produced cosmogenic isotopes to estimate rates of landcape evolution: a review from the geomorphic perspective Bierman,P.R. https://doi.org/10.1029/94JB00459
  4. Ph.D.Thesis, University of Washington Cosmogenic Isotopes and the Evolution of Granitic Landforms Bierman,P.R.
  5. Geology v.13 Southeast Australian late Mesozoic and Cenozoic denudation rates: a test for late Tertiary increases in continental denudation Bishop,P. https://doi.org/10.1130/0091-7613(1985)13<479:SALMAC>2.0.CO;2
  6. Geography v.27 Periglacial landforms in the eastern part of the main ridge of Mt. Jiri Chang,H.
  7. Advances in Periglacial Gemorphology Clark.M.J.
  8. Periglacial Geomorphology Dixon,J.C.;Abrahams,A.D.
  9. The Periglacial Environment French,H.
  10. Journal of Geophysical Research v.24 Precision of terrestrial exposure ages and erosion rates estimated from analysis of cosmogenic isotopes produced in situ Gillespie,A.R.;Bierman,P.R.
  11. Quaternary Science Reviews v.20 Terrestrial in situ cosmogenic nuclides: theory and application Gosse,C.J.;Phillips,F.M. https://doi.org/10.1016/S0277-3791(00)00171-2
  12. Journal of Geology v.104 Spatially averaged long-term erosion rates measured from in situ-produced cosmogenic nuclides in alluvial sediment Granger,D.E.;Kirchner,J.W.;Finkel,R. https://doi.org/10.1086/629823
  13. Maneo, Journal of Korean Geomorphological Association v.2 no.1 A study on the block streams in Mt. Jeon,Y.K.
  14. Halla, Naksan Geography v.1 Patterned ground of Mt. Kim,D.J.
  15. Ph.D. Thesis, University of Victoria Understanding Cosmogenic Nuclide Production Underground Kim,K.
  16. Geomorphology v.9 Preservation of landforms under ice sheets and ice caps Kleman,J.;Borgstrom,I. https://doi.org/10.1016/0169-555X(94)90028-0
  17. Geochimica et Cosmochimica Acta v.56 Chemical isolation of quartz for measurement of in-situ produced cosmogenic nuclides Kohl,C.P.;Nishiizumi,K. https://doi.org/10.1016/0016-7037(92)90401-4
  18. Journal of Geography v.6 Fossil periglacial phenomena on the southern parts of Geoje island Kwon,S.S. https://doi.org/10.1080/00221340708986195
  19. Journal of Geography v.15 On the accumulated granite boulders of the Mt. Maneo Kwon,S.S.
  20. Earth and Planetary Science Letters v.104 Cosmic ray labeling of erosion surfaces: in-situ unclide production rates and erosion models Lal,D. https://doi.org/10.1016/0012-821X(91)90220-C
  21. Korea Lautensach
  22. Earth and Planetary Science Letters v.136 Terrestrial cosmogenic-nuclide production systematics calculated from numerical simulations Masarik;Reedy https://doi.org/10.1016/0012-821X(95)00169-D
  23. Earth and Planetary Science Letters v.98 Cosmogenic $^{10}Be$ and $^{26}Al$ and $^{3}He$ in olivine from Maui lavas Nishiizumi,K.;Klein,J.;Middleton,R.;Craig,H. https://doi.org/10.1016/0012-821X(90)90028-V
  24. Geochimica et. Cosmochimica Acta. v.55 situ $^{10}Be$ and $^{26}Al$ exposure ages at Meteor Crater Nishiizumi,K.;Kohl,C.P.;Shoemaker,E.M.;Arnold,J.R.;Klein,J.(et al.) https://doi.org/10.1016/0016-7037(91)90388-L
  25. Journal of Geophysical Research v.94 no.17 Cosmic ray production rates of $^{10}Be$ and $^{26}Al$ in quartz from glacially polished rocks Nishiizumi,K.;Lal,D.;Klein,J.;Middleton,R.;Arnold,J.R. https://doi.org/10.1029/JB094iB12p17907
  26. Permafrost and Perigalcial Processes v.9 Occurrence of extrazonal periglacial landforms in the lowlands of western Japan and Korea Oguchi,T.;Tanaka,Y. https://doi.org/10.1002/(SICI)1099-1530(199807/09)9:3<285::AID-PPP289>3.0.CO;2-Q
  27. Journal of Quaternary Science v.16 no.6 Cosmogenic radionuclide dating of glacial landforms in the Lahul Himalaya, northern India: defining the timing of Late Quaternary glaciaiton Owen,L.A.;Gualtieri;Finkel,R.C.;Caffee,M.;Benn,D.I;Sharma,M. https://doi.org/10.1002/jqs.621
  28. Geomorphology v.15 Blockfields, old or new? Evidence and implications from some plateaus in northern Norwary Rea,B.R.;Whalley,W.B.;Rainey,M.M.;Gordon,J.E. https://doi.org/10.1016/0169-555X(95)00118-O
  29. Earth and Planetary Science Letters v.152 Cosmogenic dating of fluvial terraces Repka,J.L.;Anderson,R.S.;Finkel,R.C. https://doi.org/10.1016/S0012-821X(97)00149-0
  30. Earth and Planetary Science Letters v.150 no.3;4 Erosion retes of alpine bedrock summit surfaces deduced from in situ $^{10}Be$ and $^{26}Al$ Small,E.E.;Anderson,R.S.;Repka,J.L.;Finkel,R. https://doi.org/10.1016/S0012-821X(97)00092-7
  31. Geology v.26 no.7 Exposure dating and validation of periglacial weathering limits Stone,J.O.;Ballantyne,C.K.;Fifield,L.K. https://doi.org/10.1130/0091-7613(1998)026<0587:EDAVOP>2.3.CO;2
  32. Geomorphology v.27 Long-term rates of denudation in the dry valleys, transantarctic mountains,southern Victoria Land, Antarctica based on in-situ-produced cosmogenic $^{21}Ne$ Summerfield,M.A.;Stuart,F.M.;Cockburn,H.A.P.;Sudgen,D.E.;Denton,G.H.;Dunai,T.;Marchant,D.R. https://doi.org/10.1016/S0169-555X(98)00093-2
  33. Acclerator Mass Spectrometry Tuniz,C.;Bird,J.;Fink,D.;Herzog,G.