메뉴 건너뛰기




Volumn 52, Issue 2, 2005, Pages 243-260

Mantle heterogeneity beneath the Cenozoic volcanic provinces of central Victoria inferred from trace-element and Sr, Nd, Pb and Hf isotope data

Author keywords

Basalt; Cenozoic; Geochemistry; Intraplate magmatism; Isotopes; Mantle heterogeneity; Trace elements; Victoria; Volcanic rocks

Indexed keywords

CENOZOIC; ISOTOPIC COMPOSITION; MANTLE CHEMISTRY;

EID: 22744453103     PISSN: 08120099     EISSN: None     Source Type: Journal    
DOI: 10.1080/08120090500139448     Document Type: Article
Times cited : (28)

References (58)
  • 1
    • 0034318132 scopus 로고    scopus 로고
    • The thermal state of the upper mantle: No role for mantle plumes
    • Anderson D. L. 2000. The thermal state of the upper mantle: no role for mantle plumes. Geophysical Research Letters 27, 3623-3626.
    • (2000) Geophysical Research Letters , vol.27 , pp. 3623-3626
    • Anderson, D.L.1
  • 2
    • 33044492819 scopus 로고
    • The occurrence of a leucite-bearing lava at Cosgrove, Victoria
    • Birch W. D. 1976. The occurrence of a leucite-bearing lava at Cosgrove, Victoria. Journal of the Geological Society of Australia 25, 435-437.
    • (1976) Journal of the Geological Society of Australia , vol.25 , pp. 435-437
    • Birch, W.D.1
  • 3
    • 0004613616 scopus 로고
    • Mineralogy and geochemistry of the leucitite lava at Cosgrove, Victoria
    • Birch W. D. 1978. Mineralogy and geochemistry of the leucitite lava at Cosgrove, Victoria. Journal of the Geological Society of Australia 25, 369-385.
    • (1978) Journal of the Geological Society of Australia , vol.25 , pp. 369-385
    • Birch, W.D.1
  • 4
    • 0036113689 scopus 로고    scopus 로고
    • Proterozoic - Early Palaeozoic rocks and the Tyennan Orogeny in central Victoria; The Selwyn Block and its tectonic implications
    • Cayley R. A., Taylor D. H., Vandenberg A. H. M. & Moore D. H. 2002. Proterozoic - Early Palaeozoic rocks and the Tyennan Orogeny in central Victoria; the Selwyn Block and its tectonic implications. Australian Journal of Earth Sciences 49, 225-254.
    • (2002) Australian Journal of Earth Sciences , vol.49 , pp. 225-254
    • Cayley, R.A.1    Taylor, D.H.2    Vandenberg, A.H.M.3    Moore, D.H.4
  • 6
  • 7
    • 33044486131 scopus 로고
    • East Australian leucitite suite
    • Johnson R. W. ed. Cambridge University Press. Melbourne
    • Cundari A. 1989. East Australian leucitite suite. In: Johnson R. W. ed. Intraplate Volcanism in Eastern Australia and New Zealand, pp. 131-132. Cambridge University Press. Melbourne.
    • (1989) Intraplate Volcanism in Eastern Australia and New Zealand , pp. 131-132
    • Cundari, A.1
  • 8
    • 0033519382 scopus 로고    scopus 로고
    • Application of isotope dilution for precise measurement of Zr/Hf & Hf-176/Hf-177 ratios by mass spectrometry (ID-TIMS/ID-MC-ICP-MS)
    • David K., Birck J. L., Telouk P. & Allegre C. J. 1999. Application of isotope dilution for precise measurement of Zr/Hf & Hf-176/Hf-177 ratios by mass spectrometry (ID-TIMS/ID-MC-ICP-MS). Chemical Geology 157, 1-12.
    • (1999) Chemical Geology , vol.157 , pp. 1-12
    • David, K.1    Birck, J.L.2    Telouk, P.3    Allegre, C.J.4
  • 9
    • 0009511554 scopus 로고
    • Petrology and geochemistry of the Older Volcanics, Victoria
    • PhD thesis, Monash University, Melbourne (unpubl.)
    • Day R. A. 1983. Petrology and geochemistry of the Older Volcanics, Victoria. PhD thesis, Monash University, Melbourne (unpubl.).
    • (1983)
    • Day, R.A.1
  • 10
    • 0022846931 scopus 로고
    • Metallogeny and tectonic development of the Tasman Fold Belt System in New South Wales
    • Degeling P. R., Gilligan L. B., Scheibner E. & Suppel D. W. 1986. Metallogeny and tectonic development of the Tasman Fold Belt System in New South Wales. Ore Geology Reviews 1, 259-313.
    • (1986) Ore Geology Reviews , vol.1 , pp. 259-313
    • Degeling, P.R.1    Gilligan, L.B.2    Scheibner, E.3    Suppel, D.W.4
  • 11
    • 0030740097 scopus 로고    scopus 로고
    • A simple method for the precise determination of ≥ 40 trace elements in geological samples by ICPMS using enriched isotope internal standardisation
    • Eggins S. M., Woodhead J. D., Kinsley L. P. J., Mortimer G. E., Sylvester P., McCulloch M. T., Hergt J. M. & Handler M. R. 1997. A simple method for the precise determination of ≥ 40 trace elements in geological samples by ICPMS using enriched isotope internal standardisation. Chemical Geology 134, 311-326.
    • (1997) Chemical Geology , vol.134 , pp. 311-326
    • Eggins, S.M.1    Woodhead, J.D.2    Kinsley, L.P.J.3    Mortimer, G.E.4    Sylvester, P.5    McCulloch, M.T.6    Hergt, J.M.7    Handler, M.R.8
  • 12
    • 0036264993 scopus 로고    scopus 로고
    • The role of sediment recycling in EM-1 inferred from Os, Pb, Hf, Nd, Sr isotope and trace element systematics of the Pitcairn hotspot
    • Eisele J., Sharma M., Galer S. J. G., Blichert-Toft J., Devey C. W.& Hofmann A. W. 2002. The role of sediment recycling in EM-1 inferred from Os, Pb, Hf, Nd, Sr isotope and trace element systematics of the Pitcairn hotspot. Earth and Planetary Science Letters 196, 197-212.
    • (2002) Earth and Planetary Science Letters , vol.196 , pp. 197-212
    • Eisele, J.1    Sharma, M.2    Galer, S.J.G.3    Blichert-Toft, J.4    Devey, C.W.5    Hofmann, A.W.6
  • 13
    • 0022264652 scopus 로고
    • Aspects of the mineralogy and chemistry of the intermediate-silicic Cainozoic volcanic rocks of eastern Australia. Part 1: Introduction and geochemistry
    • Ewart A., Chappell B. W. & Le Maitre R. W. 1985. Aspects of the mineralogy and chemistry of the intermediate-silicic Cainozoic volcanic rocks of eastern Australia. Part 1: Introduction and geochemistry. Australian Journal of Earth Sciences 32, 359-382.
    • (1985) Australian Journal of Earth Sciences , vol.32 , pp. 359-382
    • Ewart, A.1    Chappell, B.W.2    Le Maitre, R.W.3
  • 14
    • 31144464962 scopus 로고
    • An overview of the geochemical and isotopic characteristics of the eastern Australian Cainozoic volcanic provinces
    • Cox K. G. & Menzies M. A. eds. Journal of Petrology Special Volume
    • Ewart A., Chappell B. W. & Menzies M. A. 1988. An overview of the geochemical and isotopic characteristics of the eastern Australian Cainozoic volcanic provinces. In: Cox K. G. & Menzies M. A. eds. Oceanic and Continental Lithosphere: Similarities and Differences, pp. 225-274. Journal of Petrology Special Volume.
    • (1988) Oceanic and Continental Lithosphere: Similarities and Differences , pp. 225-274
    • Ewart, A.1    Chappell, B.W.2    Menzies, M.A.3
  • 15
    • 77957246665 scopus 로고
    • Integrated models of basalt petrogenesis: A study of quartz tholeiites to olivine melilitites from southeastern Australia utilizing geochemical and experimental petrological data
    • Frey R. A., Green D. H. & Roy S. D. 1978. Integrated models of basalt petrogenesis: a study of quartz tholeiites to olivine melilitites from southeastern Australia utilizing geochemical and experimental petrological data. Journal of Petrology 19, 463-513.
    • (1978) Journal of Petrology , vol.19 , pp. 463-513
    • Frey, R.A.1    Green, D.H.2    Roy, S.D.3
  • 16
    • 22744449954 scopus 로고    scopus 로고
    • Insights into the Newer Volcanics Province of Victoria
    • Specialist Group in Geochemistry, Mineralogy and Petrology Field Guide
    • Graham I. T., Hollis J. D., Sutherland F. L. & Joyce E. B. 2003. Insights into the Newer Volcanics Province of Victoria. Geological Society of Australia, Specialist Group in Geochemistry, Mineralogy and Petrology Field Guide 5.
    • (2003) Geological Society of Australia , vol.5
    • Graham, I.T.1    Hollis, J.D.2    Sutherland, F.L.3    Joyce, E.B.4
  • 17
    • 0041542027 scopus 로고    scopus 로고
    • The persistence of off-cratonic lithospheric mantle: Os isotopic systematics of variably metasomatised southeast Australian xenoliths
    • Handler M. R., Bennett V. C. & Esat T. M. 1997. The persistence of off-cratonic lithospheric mantle: Os isotopic systematics of variably metasomatised southeast Australian xenoliths. Earth and Planetary Science Letters 151, 61-75.
    • (1997) Earth and Planetary Science Letters , vol.151 , pp. 61-75
    • Handler, M.R.1    Bennett, V.C.2    Esat, T.M.3
  • 18
    • 0013630589 scopus 로고
    • The age and physiographic relationship of the Cenozoic volcanic rocks of Victoria
    • Hills E. S. 1938. The age and physiographic relationship of the Cenozoic volcanic rocks of Victoria. Proceedings of the Royal Society of Victoria 51, 112-139.
    • (1938) Proceedings of the Royal Society of Victoria , vol.51 , pp. 112-139
    • Hills, E.S.1
  • 20
    • 0030998901 scopus 로고    scopus 로고
    • Mantle geochemistry; The message from oceanic volcanism
    • Hofmann A. W. 1997. Mantle geochemistry; the message from oceanic volcanism. Nature 385, 219-229.
    • (1997) Nature , vol.385 , pp. 219-229
    • Hofmann, A.W.1
  • 21
    • 0345542583 scopus 로고
    • Volcano classification and distribution
    • Johnson R. W. ed. Cambridge University Press, Melbourne
    • Johnson R. W. 1989. Volcano classification and distribution. In: Johnson R. W. ed. Intraplate Volcanism in Eastern Australia and New Zealand, pp. 7-12. Cambridge University Press, Melbourne.
    • (1989) Intraplate Volcanism in Eastern Australia and New Zealand , pp. 7-12
    • Johnson, R.W.1
  • 22
    • 33044491410 scopus 로고
    • Introduction to Intraplate Volcanism. Preview
    • Johnson R. W. ed. Cambridge University Press, Melbourne
    • Johnson R. W. & Taylor S. R. 1989. Introduction to Intraplate Volcanism. Preview. In: Johnson R. W. ed. Intraplate Volcanism in Eastern Australia and New Zealand, pp. 1-3. Cambridge University Press, Melbourne.
    • (1989) Intraplate Volcanism in Eastern Australia and New Zealand , pp. 1-3
    • Johnson, R.W.1    Taylor, S.R.2
  • 24
  • 26
    • 0000277294 scopus 로고
    • Detachment models for uplift and volcanism in the eastern highlands, and their application to the origin of passive margin mountains
    • Johnson R. W. ed. Cambridge University Press, Melbourne
    • Lister G. S. & Etheridge M. A. 1989. Detachment models for uplift and volcanism in the eastern highlands, and their application to the origin of passive margin mountains. In: Johnson R. W. ed. Intraplate Volcanism in Eastern Australia and New Zealand, pp. 297-313. Cambridge University Press, Melbourne.
    • (1989) Intraplate Volcanism in Eastern Australia and New Zealand , pp. 297-313
    • Lister, G.S.1    Etheridge, M.A.2
  • 28
    • 0030478096 scopus 로고    scopus 로고
    • Multistage evolution of Australian subcontinental mantle: Re-Os isotopic constraints from Victorian mantle xenoliths
    • Mcbride J. S., Lambert D. D., Greig A & Nicholls I. A. 1996. Multistage evolution of Australian subcontinental mantle: Re-Os isotopic constraints from Victorian mantle xenoliths. Geology 24, 631-634.
    • (1996) Geology , vol.24 , pp. 631-634
    • McBride, J.S.1    Lambert, D.D.2    Greig, A.3    Nicholls, I.A.4
  • 29
    • 0034967307 scopus 로고    scopus 로고
    • Osmium isotopic evidence for crust-mantle interaction in the genesis of continental intraplate basalts from the Newer Volcanics Province, southeastern Australia
    • McBride J. S., Lambert D. D., Nicholls I. A. & Price R. C. 2001. Osmium. isotopic evidence for crust-mantle interaction in the genesis of continental intraplate basalts from the Newer Volcanics Province, southeastern Australia. Journal of Petrology 42, 1197-1218.
    • (2001) Journal of Petrology , vol.42 , pp. 1197-1218
    • McBride, J.S.1    Lambert, D.D.2    Nicholls, I.A.3    Price, R.C.4
  • 30
    • 0022264299 scopus 로고
    • Isotopic and geochemical systematics in Tertiary - Recent basalts from southeastern Australia and implications for the evolution of the subcontinental lithosphere
    • McDonough W. F., McCulloch M. T. & Sun S-S. 1985. Isotopic and geochemical systematics in Tertiary - Recent basalts from southeastern Australia and implications for the evolution of the subcontinental lithosphere. Geochimica et Cosmochimica Acta 49, 2051-2067.
    • (1985) Geochimica Et Cosmochimica Acta , vol.49 , pp. 2051-2067
    • McDonough, W.F.1    McCulloch, M.T.2    Sun, S.-S.3
  • 31
    • 0004818363 scopus 로고
    • Isotopic dating of the Newer Volcanics of Victoria, Australia and geomagnetic polarity epochs
    • McDougall I., Allsop H. L. & Chamalaun F. H. 1966. Isotopic dating of the Newer Volcanics of Victoria, Australia and geomagnetic polarity epochs. Journal of Geophysical Research 71, 6107-6118.
    • (1966) Journal of Geophysical Research , vol.71 , pp. 6107-6118
    • McDougall, I.1    Allsop, H.L.2    Chamalaun, F.H.3
  • 33
    • 0001003126 scopus 로고
    • Hotspot tracks and the opening of the Atlantic and Indian oceans
    • Emiliani C. ed. Wiley-Interscience, New York
    • Morgan W. J. 1981, Hotspot tracks and the opening of the Atlantic and Indian oceans. In: Emiliani C. ed. The Sea, vol. 7, pp. 443-487. Wiley-Interscience, New York.
    • (1981) The Sea , vol.7 , pp. 443-487
    • Morgan, W.J.1
  • 34
    • 0022554995 scopus 로고
    • The origins of ultrapotassic rocks as inferred from Sr, Nd and Pb isotopes
    • Nelson D. R., McCulloch M. T. & Sun S-S. 1986. The origins of ultrapotassic rocks as inferred from Sr, Nd and Pb isotopes. Geochimica et Cosmachimica Acta 50, 231-245.
    • (1986) Geochimica Et Cosmachimica Acta , vol.50 , pp. 231-245
    • Nelson, D.R.1    McCulloch, M.T.2    Sun, S.-S.3
  • 36
    • 0001620231 scopus 로고
    • Geochemical characteristics of lava-field basalts from eastern Australia and inferred sources: Connections with the subcontinental lithospheric mantle?
    • O'Reilly S. Y. & Zhang M. 1995. Geochemical characteristics of lava-field basalts from eastern Australia and inferred sources: connections with the subcontinental lithospheric mantle? Contributions to Mineralogy and Petrology 121, 148-170.
    • (1995) Contributions to Mineralogy and Petrology , vol.121 , pp. 148-170
    • O'Reilly, S.Y.1    Zhang, M.2
  • 37
    • 0001885185 scopus 로고
    • Petrology of igneous rocks
    • Douglas J. R. & Ferguson J. A. eds. Geological Society of Australia, Victorian Division, Melbourne
    • Price R. C., Gray C. M., Nicholls I. A. & Day R. A. 1988. Petrology of igneous rocks. In: Douglas J. R. & Ferguson J. A. eds. Geology of Victoria, pp. 439-451. Geological Society of Australia, Victorian Division, Melbourne.
    • (1988) Geology of Victoria , pp. 439-451
    • Price, R.C.1    Gray, C.M.2    Nicholls, I.A.3    Day, R.A.4
  • 38
    • 0030790685 scopus 로고    scopus 로고
    • Strontium isotopic and trace element heterogeneity in the plains basalts of the Newer Volcanic province, Victoria, Australia
    • Price R. C., Gray C. M. & Frey F. A. 1997. Strontium isotopic and trace element heterogeneity in the plains basalts of the Newer Volcanic province, Victoria, Australia. Geochimica et Cosmochimica Acta 61, 171-192.
    • (1997) Geochimica Et Cosmochimica Acta , vol.61 , pp. 171-192
    • Price, R.C.1    Gray, C.M.2    Frey, F.A.3
  • 39
    • 4444278575 scopus 로고    scopus 로고
    • Cainozoic igneous activity; widespread volcanism resulting from long-term mantle instability and rifting
    • Birch W. D. ed. Geological Society of Australia Special Publication 23
    • Price R. C., Nicholls I. A. & Gray C. M. 2003. Cainozoic igneous activity; widespread volcanism resulting from long-term mantle instability and rifting. In: Birch W. D. ed. Geology of Victoria, pp. 361-375. Geological Society of Australia Special Publication 23.
    • (2003) Geology of Victoria , pp. 361-375
    • Price, R.C.1    Nicholls, I.A.2    Gray, C.M.3
  • 43
    • 0024939253 scopus 로고
    • Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes
    • Saunders A. D. & Norry M. J. eds. Geological Society of London Special Publication 42
    • Sun S-S. & McDonough W. F. 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: Saunders A. D. & Norry M. J. eds. Magmatism in the Ocean Basins, pp. 313-345. Geological Society of London Special Publication 42.
    • (1989) Magmatism in the Ocean Basins , pp. 313-345
    • Sun, S.-S.1    McDonough, W.F.2
  • 44
    • 0041372663 scopus 로고
    • Regional controls in eastern Australian volcanism
    • Sutherland F. L., Franklin B. J. & Waltho A. E. eds. Geological Society of Australia, New South Wales Division, Sydney, Publication 1
    • Sutherland F. L. 1985. Regional controls in eastern Australian volcanism. In: Sutherland F. L., Franklin B. J. & Waltho A. E. eds. Volcanism in Eastern Australia with Case Histories from New South Wales, pp. 13-31. Geological Society of Australia, New South Wales Division, Sydney, Publication 1.
    • (1985) Volcanism in Eastern Australia With Case Histories from New South Wales , pp. 13-31
    • Sutherland, F.L.1
  • 45
    • 78049238793 scopus 로고    scopus 로고
    • Boomerang migratory intraplate Cenozoic volcanism, eastern Australia rift margins and the Indo-Pacific mantle boundary
    • Hillis R. R. & Müller R. D. eds. Geological Society of Australia Special Publication 22 and Geological Society of America Special Paper 372
    • Sutherland F. L. 2003, Boomerang migratory intraplate Cenozoic volcanism, eastern Australia rift margins and the Indo-Pacific mantle boundary. In: Hillis R. R. & Müller R. D. eds. Evolution and Dynamics of the Australian Plate, pp. 203-221. Geological Society of Australia Special Publication 22 and Geological Society of America Special Paper 372.
    • (2003) Evolution and Dynamics of the Australian Plate , pp. 203-221
    • Sutherland, F.L.1
  • 47
    • 0030749341 scopus 로고    scopus 로고
    • The petrogenesis and platinum-group element geochemistry of the Newer Volcanic Province, Victoria, Australia
    • Vogel D. C. & Keays R. R. 1997. The petrogenesis and platinum-group element geochemistry of the Newer Volcanic Province, Victoria, Australia. Chemical Geology 136, 181-204
    • (1997) Chemical Geology , vol.136 , pp. 181-204
    • Vogel, D.C.1    Keays, R.R.2
  • 48
    • 0000478196 scopus 로고
    • Potassium-argon ages of Cainozoic volcanic rocks of eastern Victoria, Australia
    • Wellman P. 1974. Potassium-argon ages of Cainozoic volcanic rocks of eastern Victoria, Australia. Journal of the Geological Society of Australia 21, 359-376.
    • (1974) Journal of the Geological Society of Australia , vol.21 , pp. 359-376
    • Wellman, P.1
  • 49
    • 0020975159 scopus 로고
    • Hotspot volcanism in Australia and New Zealand: Cainozoic and mid-Mesozoic
    • Wellman P. 1983. Hotspot volcanism in Australia and New Zealand: Cainozoic and mid-Mesozoic. Tectonophysics 96, 225-243.
    • (1983) Tectonophysics , vol.96 , pp. 225-243
    • Wellman, P.1
  • 51
    • 0002144564 scopus 로고
    • Cainozoic Igneous Activity in Eastern Australia
    • Wellman P. & McDougall I. 1974. Cainozoic Igneous Activity in Eastern Australia. Tectonophysics 23, 49-65.
    • (1974) Tectonophysics , vol.23 , pp. 49-65
    • Wellman, P.1    McDougall, I.2
  • 52
    • 0001226394 scopus 로고
    • Temporal geochemical evolution in oceanic intraplate volcanics: A case study from the Marquesas (French Polynesia) and comparison with other hotspots
    • Woodhead J. D. 1992. Temporal geochemical evolution in oceanic intraplate volcanics: a case study from the Marquesas (French Polynesia) and comparison with other hotspots. Contributions to Mineralogy and Petrology 111, 458-467.
    • (1992) Contributions to Mineralogy and Petrology , vol.111 , pp. 458-467
    • Woodhead, J.D.1
  • 53
    • 0036026510 scopus 로고    scopus 로고
    • A simple method for obtaining highly accurate Pb isotope data by MC-ICP-MS
    • Woodhead J. D. 2002. A simple method for obtaining highly accurate Pb isotope data by MC-ICP-MS. Journal of Analytical Atomic Spectrometry 17, 1-6.
    • (2002) Journal of Analytical Atomic Spectrometry , vol.17 , pp. 1-6
    • Woodhead, J.D.1
  • 54
    • 0027388291 scopus 로고
    • Geochemistry of the Pitcairn seamounts, I: Source character and temporal trends
    • Woodhead J. D. & Devey C. W. 1993. Geochemistry of the Pitcairn seamounts, I: source character and temporal trends. Earth and Planetary Science Letters 116, 81-99.
    • (1993) Earth and Planetary Science Letters , vol.116 , pp. 81-99
    • Woodhead, J.D.1    Devey, C.W.2
  • 55
    • 0035164432 scopus 로고    scopus 로고
    • Hafnium, isotope evidence for 'conservative' element mobility during subduction zone processes
    • Woodhead J. D., Hergt J. M., Davidson J. P. & Eggins S. M. 2001. Hafnium, isotope evidence for 'conservative' element mobility during subduction zone processes. Earth and Planetary Science Letters 192, 331-346.
    • (2001) Earth and Planetary Science Letters , vol.192 , pp. 331-346
    • Woodhead, J.D.1    Hergt, J.M.2    Davidson, J.P.3    Eggins, S.M.4
  • 56
    • 0024936759 scopus 로고
    • Ancient seaffoor signals in Pitcairn Island lavas and evidence for large amplitude, small length-scale mantle heterogeneities
    • Woodhead J. D. & McCulloch M. T. 1989. Ancient seaffoor signals in Pitcairn Island lavas and evidence for large amplitude, small length-scale mantle heterogeneities. Earth and Planetary Science Letters 94, 257-273.
    • (1989) Earth and Planetary Science Letters , vol.94 , pp. 257-273
    • Woodhead, J.D.1    McCulloch, M.T.2
  • 57
    • 0030797084 scopus 로고    scopus 로고
    • Multiple sources for basaltic rocks from Dubbo, eastern Australia: Geochemical evidence for plume-lithosphere mantle interaction
    • Zhang M. & O'Reilly S. Y. 1997. Multiple sources for basaltic rocks from Dubbo, eastern Australia: geochemical evidence for plume-lithosphere mantle interaction. Chemical Geology 136, 33-54.
    • (1997) Chemical Geology , vol.136 , pp. 33-54
    • Zhang, M.1    O'Reilly, S.Y.2


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.