簡易檢索 / 詳目顯示

研究生: 阮氏妙
Nguyen Thi Dieu
論文名稱: Geochronology and geochemical characteristics of Precambrian granite in the Main Islands, Republic of Seychelles
Geochronology and geochemical characteristics of Precambrian granite in the Main Islands, Republic of Seychelles
指導教授: John Gregory Shellnutt
John Gregory Shellnutt
學位類別: 碩士
Master
系所名稱: 地球科學系
Department of Earth Sciences
論文出版年: 2019
畢業學年度: 107
語文別: 英文
論文頁數: 119
中文關鍵詞: Seychellesferroan granitepost-collisonal extensionzircon geochronology
英文關鍵詞: Seychelles, ferroan granite, post-collisonal extension, zircon geochronology
DOI URL: http://doi.org/10.6345/THE.NTNU.DES.001.2019.B07
論文種類: 學術論文
相關次數: 點閱:111下載:21
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報
  • The Seychelles microcontinent located in western Indian Ocean consists of a large number of granitic islands. The oldest known rocks of the Seychelles microcontinent are Neoproterozoic and comprise the Main Islands (Mahé and Praslin group). Previous studies demonstrated that the emplacement age of the Neoproterozoic granites is ~750 Ma although the age of Île aux Récifs is ~50 million years older (808.8±1.9 Ma). New weighted-mean zircon 238U/206Pb ages for rocks collected from northern Mahé (750.6±4.1 Ma, 756.9±4.5 Ma, 756.4±5.1 Ma) and western Praslin (761±12 Ma, 754.2±6.9 Ma, 753.8±4.9 Ma) are reported in this study. The new radioisotopic ages overlap with previous results but a significant number of inherited zircons were identified that fall within two major groups: ~790 Ma to ~820 Ma and ~850 Ma to 880 Ma. Geochemically, the Seychelles granites are characterized by high SiO2 and are metaluminous to peraluminous, alkali-calcic to calc-alkalic, and ferroan. The negative correlation of SiO2 with Al2O3, Fe2O3, CaO, TiO2, MgO and P2O5 indicates that the rock experienced crystal fractionation either during or after emplacement. They also show the enrichment in light rare earth elements compared to heavy rare earth elements with distinct negative Eu anomalies (0.1-0.84). Mahé samples illustrate positive εNd(t) = +1.85 to +2.83, and ISr values from 0.7022 to 0.7031 while those of Praslin shows negative εNd(t) = -1.52 to -1.29 and extremely low ISr values. Consequently, it appears that the Mahé and Praslin granites are derived from different sources. Tectonomagmatic discrimination of the granites is compatible with within-plate or post-orogenic environment. The ~50 million year gap between the oldest and youngest rocks, and their compositional (within-plate vs. volcanic-arc) dichotomy are difficult to reconcile. It is likely that Neoproterozoic granites of the Seychelles microcontinent were not associated with a volcanic-arc but rather related to post-collision extension or rifting. Furthermore, it is possible that the age of Île aux Récifs may be indicative of inherited zircon and not the emplacement age.

    The Seychelles microcontinent located in western Indian Ocean consists of a large number of granitic islands. The oldest known rocks of the Seychelles microcontinent are Neoproterozoic and comprise the Main Islands (Mahé and Praslin group). Previous studies demonstrated that the emplacement age of the Neoproterozoic granites is ~750 Ma although the age of Île aux Récifs is ~50 million years older (808.8±1.9 Ma). New weighted-mean zircon 238U/206Pb ages for rocks collected from northern Mahé (750.6±4.1 Ma, 756.9±4.5 Ma, 756.4±5.1 Ma) and western Praslin (761±12 Ma, 754.2±6.9 Ma, 753.8±4.9 Ma) are reported in this study. The new radioisotopic ages overlap with previous results but a significant number of inherited zircons were identified that fall within two major groups: ~790 Ma to ~820 Ma and ~850 Ma to 880 Ma. Geochemically, the Seychelles granites are characterized by high SiO2 and are metaluminous to peraluminous, alkali-calcic to calc-alkalic, and ferroan. The negative correlation of SiO2 with Al2O3, Fe2O3, CaO, TiO2, MgO and P2O5 indicates that the rock experienced crystal fractionation either during or after emplacement. They also show the enrichment in light rare earth elements compared to heavy rare earth elements with distinct negative Eu anomalies (0.1-0.84). Mahé samples illustrate positive εNd(t) = +1.85 to +2.83, and ISr values from 0.7022 to 0.7031 while those of Praslin shows negative εNd(t) = -1.52 to -1.29 and extremely low ISr values. Consequently, it appears that the Mahé and Praslin granites are derived from different sources. Tectonomagmatic discrimination of the granites is compatible with within-plate or post-orogenic environment. The ~50 million year gap between the oldest and youngest rocks, and their compositional (within-plate vs. volcanic-arc) dichotomy are difficult to reconcile. It is likely that Neoproterozoic granites of the Seychelles microcontinent were not associated with a volcanic-arc but rather related to post-collision extension or rifting. Furthermore, it is possible that the age of Île aux Récifs may be indicative of inherited zircon and not the emplacement age.

    ACKNOWLEDGEMENT ii Table of contents iii List of figures vi List of pictures ix List of tables x Abbreviations xi Abstract 1 CHAPTER 1. INTRODUCTION 3 1.1. Continental crust 3 1.2. Super continental cycles 4 1.3. Relationship between Rodinia and Gondwana 5 1.4. East African Orogen 8 1.5. The Seychelles microcontinent 12 1.6. Purpose of the study 14 CHAPTER 2. GEOLOGICAL BACKGROUND 18 2.1. Mahé group island 19 2.2. The Praslin - La Digue island group 22 2.3. Sampling 24 CHAPTER 3. PETROGRAPHY 28 3.1. Mahé granites 28 3.2. Praslin granites 31 CHAPTER 4. METHODS 36 4.1. Zircon U-Pb dating by LA-ICPMS 36 4.1.1. Zircon preparation 36 4.1.2. Principles of zircon U-Pb geochronology 37 4.1.3. Procedure of U-Pb geochronology 38 4.2. Whole rock major elements by XRF 39 4.2.1. Principles of X-ray Fluorescence spectrometry 39 4.2.2. Procedure 39 4.3. Whole rock trace elements by ICP-MS 41 4.3.1. Principles of ICP-MS 41 4.3.2. Procedure 42 4.4. Whole rock Sr-Nd isotopes by TIMS 43 4.4.1. Principles of TIMS operation 43 4.4.2. Procedure 43 CHAPTER 5. RESULTS 46 5.1. Zircon geochronology 46 5.1.1. Zircons morphology 46 5.1.2. Zircon U-Pb ages 49 5.2. Geochemistry 54 5.2.1. Major elements geochemistry 54 5.2.2. Trace element geochemistry 58 5.2.3. Sr-Nd Isotopes 61 CHAPTER 6. DISCUSSION 64 6.1. Geochronology of the Seychelles microcontinent 64 6.1.1. Age of emplacement 64 6.1.2. Age of inheritance 65 6.1.3. Regional temporal correlation 67 6.2. Petrogenesis 68 6.3. Tectonic setting of the Seychelles microcontinent 70 6.3.1. Tectonic setting 70 6.3.2. Regional tectonic correlation 74 6.4. Tectonomagmatic evolution of the Seychelles microcontinent 76 CONCLUSIONS 78 REFERENCES 79 Appendix A 92 Appendix B 99

    Andersen, T., 2002. Correction of common lead in U-Pb analyses that do not report 204Pb. Chemical Geology 192, 59-79.
    Archibald, D.B., Collins, A.S., Foden, J.D., Payne, J.L., Holden, P., Razakamanana, T., De Waele, B., Thomas, R.J., and Pitfield, P.E.J., 2016. Genesis of the Tonian Imorona–Itsindro magmatic Suite in central Madagascar: Insights from U–Pb, O and Hf isotopes in zircon. Precambrian Research 281, 312-337.
    Armistead, S.E., Collins, A., Payne, J., Cox, G., Merdith, A., Foden, J., and De Waele, B., 2018. Evolving marginal terranes during Neoproterozoic supercontinent reorganisation: constraints from the Bemarivo Belt in northern Madagascar. Manuscript.
    Ashwal, L.D., Demaiffe, D., and Torsvik, T.H., 2002. Petrogenesis of Neoproterozoic granitoids and related rocks from the Seychelles: the case for an Andean-type arc origin. The Journal of Geology 43(1), 45-83.
    Baker, B.H., 1963. Geology and mineral resources of the Seychelles archipelago. The Geological Survey of Kenya.
    Baker, B.H., and Miller, J.H., 1963. Geology and geochronology of the Seychelles Islands and the structure of the floor of the Arabian Sea. Nature 199, 346-348.
    Barth, M., McDonough, W.F., and Rudnick, R.L., 2000. Tracking the budget of Nb and Ta in the continental crust. Chemical Geology 165, 197-213.
    Batchelor, R.A., and Bowden, P., 1985. Petrogenetic Interpretation of Granitoid Rock Series Using Multicationic Parameters. Chemical Geology 48, 43-55.
    Be'eri-Shlevin, Y., Eyal, M., Eyal, Y., Whitehouse, M.J., and Litvinovsky, B., 2012. The Sa'al volcano-sedimentary complex (Sinai, Egypt): a latest Mesoproterozoic volcanic arc in the northern Arabian Nubian Shield. Geology 40, 403-406.
    BGS-USGS-GLW, 2008. Republique de Madagascar Ministère de L’engergie et des Mines. Britsh Geological Survey Research Report.
    Bhushan, S. K., 2000. Malani Rhyolite - a review. Gondwana Research 3(1), 65-77.
    Carlson, R.L., Christensen, N.I., and Moore, R.P., 1980. Anomalous crustal structures in ocean basins: Continental fragments and oceanic plateaus. Earth and Planetary Science Letters 51, 171-180.
    Cawood, P.A., Hawkesworth, C.J., and Dhuime, B., 2013. The continental record and the generation of continental crust. The Geological Society of America Bulletin 125(1-2), 14-32.
    Chadwick, B., Vasudev, V., and Hegde, G., 2000. The Dharwar craton, southern India, interpreted as the result of Late Archean oblique convergence. Precambrian Research 99, 91-111.
    Chiu, H.Y., Chung, S.L., Wu, F.Y., Liu, D., Liang, Y.H., Lin, I.J., Iizuka, Y., Xie, L.W., Wang, Y., and Chu, M.F., 2009. Zircon U–Pb and Hf isotopic constraints from eastern Transhimalayan batholiths on the precollisional magmatic and tectonic evolution in southern Tibet. Tectonophysics 477, 3-19.
    Clarke, D.B., Henry, A.S., and Hamilton, M.A., 2005. Composition, age, and origin of granitoid rocks in the Davin Lake area, Rottenstone Domain, Trans-Hudson Orogen, northern Saskatchewan. Canadian Journal of Earth Sciences 42, 599-633.
    Cloos, M., 1993. Lithospheric buoyancy and collisional orogenesis: Subduction of oceanic plateaus, continental margins, island arcs, spreading ridges, and seamounts. Geological Society of America Bulletin 105(6), 715-737.
    Cogley, J.G., 1984. Continental margins and the extent and number of the continents. Reviews of Geophysics 22(2), 101-122.
    Collins, A.S., 2000. The tectonic evolution of Madagascar: its place in the East African Orogen. Gondwana Research 3, 549-552.
    Collins, A.S., 2006. Madagascar and the amalgamation of Central Gondwana. Gondwana Research 9, 3-16.
    Collins, A.S., and Pisarevsky, S.A., 2005. Amalgamating eastern Gondwana: the evolution of the Circum-Indian Orogens. Earth Sciences Review 713, 229-270.
    Collins, A.S., and Windley, B.F., 2002. Tectonic evolution of central and northern Mada-gascar and its place in the final assembly of Gondwana. The Journal of Geology 110, 325-339.
    Collins, A.S., Windley, B., Kröner, A., Fitzsimons, I., and Hulscher, B., 2001. The tectonic architecture of central Madagascar: implications this places on the evolution of the East African Orogeny. Gondwana Research 4, 52-153.
    Cox, R., Armstrong, R.A., and Ashwal, L.D., 1998. Sedimentology, geochronology and provenance of the Proterozoic Itremo Group, central Madagascar, and implications for pre-Gondwana palaeogeography. Journal of the Geological Society 155, 1009-1024.
    Crawford, W.J., and Comptson, W., 1970. The age of the Vindhyan system of Penisular India. The Quarterly Journal of the Geological Society of London 125, 351-372.
    D’Agrella-Filho, M.S., Pacca, I.I.G., Trindade, R.I.F., Teixeira, W., Raposo, M.I.B., and Onstott, T.C., 2004. Paleomagnetism and Ar-40/Ar-39 ages of mafic dikes from Salvador (Brazil): new constraints on the Sao Francisco craton APW path between 1080 and 1010 Ma. Precambrian Research 132, 55-77.
    Demaiffe, D., Hertogen, J., and Michot, J., 1982. The granitic rocks of the Seychelles Islands and their enclaves: Part I: REE and Sr isotope geochemistry (abstract). Terra Cogn 2.
    DePaolo, D.J., Linn, A.M., and Schubert, G., 1991. The continental crustal age distribution: Methods of determining mantle separation ages from Sm‐Nd isotopic data and application to the southwestern United States. Journal of Geophysical Research: Solid Earth 96(B2), 2071-2088.
    DePaolo, D.J., and Wasserburg, G.J., 1979. Petrogenetic mixing models and Nd-Sr isotopic patterns. Geochimica et Cosmochimica Acta 43(4), 615-627.
    Dewey, J., and Burke, K., 1973. Tibetan, Variscan and Precambrian basement reactivation: products of continental collision. The Journal of Geology 81, 683-692.
    Dhar, S., Robert, E, Kramers, J. D., Nagler, T. E., and Kochhar, N., 1996. Sr, Pb and Nd isotope studies and their bearing on the petrogenesis of Jalore and Siwana complexes, Rajasthan. Journal of the Geological Society of India 48.
    Du Toit, A.L., 1937. Our Wandering Continents. Oliver and Boyd, London (366 pp.)
    Eby, G.N., 1992. Chemical subdivision of the A-type granitoids: petrogenetic and tectonic implications. Geology 20, 641-644.
    Eby, G.N., and Kochhar, N., 1990. Geochemistry and petrogenesis of the Malani Igneous Suite, northern India. The Journal of Geological Society of India 36, 109-130.
    Fritz, H., Abdelsalam, M., Ali, K.A., Bingen, B., Collins, A.S., Fowler, A.R., Ghebreab, W., Hauzenberger, C.A., Johnson, P.R., Kusky, T.M., Macey, P., Muhongo, S., Stern, R.J., and Viola, G., 2013. Orogen styles in the East African Orogen: A review of the Neoproterozoic to Cambrian tectonic evolution. Journal of African Earth Sciences 86.
    Frost, B.R., Barnes, C.G., Collins, W.J., Arculus, R.J., Ellis, D.J., and Frost, C.D., 2001. A geochemical classification for granitic rocks. Journal of Petrology 42(11), 2033-2048.
    Frost, C.D., and Frost, B.R., 2011. On ferroan (A-type) granitoids: their compositional variability and modes of origin. The Journal of Petrology 52, 39-53.
    Griffin, W.L., Powell, W.J., Pearson, N.J., and O’Reilly, S.Y., 2008. GLITTER: Data reduction software for laser ablation ICP-MS, in Laser Ablation ICP-MS in the Earth Sciences: Current Practices and Outstanding Issues, Mineral. Assoc. Can. Short Course Ser. 40.
    Hargraves, R.B., and Duncan, R.A., 1990. Radiometric age and palaeomagnetic results from Seychelles dikes. In: Duncan, R.A., Backman, J., Peterson, L.C. (Eds.), Proceedings of the Ocean Drilling Program, Scientific results 115, 119-122.
    Jackson, S.E., Pearson,, N.J., Griffin, W.L., and Belousova, E.A., 2004. The application of laser ablation inductively coupled plasma mass spectrometry to in situ U-Pb zircon geochronology. Chemical Geology 211, 47-69.
    Kennedy, W.Q., 1964. The structural differentiation of Africa in the Pan-African (±500 my) tectonic episode. Annual Reports of the Institute of African Geology 8, 48-49.
    Key, R.M., Pitfield, P.E.J., Thomas, R.J., Goodenough, K.M., De Waele, B., and Schofield D.I., 2011. Polyphase Neoproterozoic orogenesis within the East Africa–Antarctica Orogenic Belt in central and northern Madagascar. Geological Society, London, Special Publication 357, 49-68.
    Kröner, A., 2000. Age and magmatic history of the Antananarivo Block, central Madagascar, as derived from zircon geochronology and Nd isotopic systematics. American Journal of Science 300, 251-288.
    Kröner, A., and Stern, B., 2004. Pan - African Orogeny. Encyclopedia of Geology 1, 1-12.
    Li, Z.X., Li, X.H., Kinny, P.D., Wang, J., Zhang, S., and Zhou, H., 2003. Geochronology of Neoproterozoic syn-rift magmatism in the Yangtze Craton South China and correlations with other continents: evidence for a mantle superplume that broke up Rodinia. Precambrian Research 122, 85-109.
    Linnemann, U., Gerdes, A., Drost, K., and Buschmann, B., 2007. The continuum between Cadomian Orogenesis and opening of the Rheic Ocean: Constraints from LA-ICPMS U–Pb zircon dating and analysis of plate-tectonic setting (Saxo-Thuringian Zone, NE Bohemian massif, Germany). Geological Society of America 423, 61-96.
    Loiselle, M.C., and Wones, D.R., 1979. Characteristics and origin of anorogenic granites. Geological Society of America Abstracts with Programs 11 (7), 468.
    Ludwig, K.R., 2012. Isoplot 3.75: A geochronological toolkit for Microsoft Excel, Special Publication 5, Berkeley Geochronology Center, Berkeley, California, 75p.
    Maniar, P.D., and Piccoli, P.M., 1989. Tectonic Discrimination of Granitoids. Geological Society of America Bulletin 101, 635-643.
    McMenamin, M.A.S., and McMenamin, D.L.S., 1990. The Emergence of Animals: The Cambrian Breakthrough. Columbia University Press: New York.
    Meert, J.G., and Pandit, M.K., 2015. The Archean and Proterozoic history of Peninsular India: tectonic framework for Precambrian sedimentary basins in India. Geological Society, London, Memoirs 43, 29-54.
    Meert, J.G., and Torsvik, T.H., 2003. The making and unmaking of a supercontinent: Rodinia revisited. Tectonophysics 375, 261-288.
    Meert, J.G., and Van Der Voo, R., 1997. The assembly of Gondwana 800-550 Ma. Journal of Geodynamics 23, 223-235.
    Meert, J.G., Van der Voo, R., and Ayub, S., 1995. Paleomagnetic investigation of the Neoproterozoic Gagwe lavas and Mbozi Complex Tanzania and the assembly of Gondwana. Precambrian Research 74, 225-244.
    Meredith, A., Collins, A., Williams, S., Pisarevskiy, S., Foden, J., Archibald, D., Blades, M., Alessio, B., Armistead, S., Plavsa, D., Clark, C., and Müller, R., 2016. A full-plate global reconstruction of the Neoproterozoic. Gondwana Research 50, 84-134.
    Michot, J., and Deutsch, S., 1977. Les Seychelles, un nucléus sialique. Ann. Soc. Géol. Belg. 100.
    Miller, J.A., and Mudie, J.D., 1961. Potassium-argon age determinations on granite from the islands of Mahé in the Seychelles archipelago. Nature 192, 1174-1175.
    Miller, K.C., and Hargraves, R.B., 1994. Paleomagnetism of Some Indian Kimberlites and Lamproites. Precambrian Research 69, 259-267.
    Mooney, W.D., Laske, G., and Masters, T.G., 1998, Crust 5.1: A global crustal model at 5° × 5°. Journal of Geophysical Research 103, 727-747.
    Pearce, J.A., Harris, N.B.W., and Tindle, A.G., 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. The Journal of Petrology 25, 956-983.
    Pisarevsky, S.A., Wingate, M.T.D., Powell, C.M., Johnson, S., and Evans, D.A.D., 2003b. Models of Rodinia assembly and fragmentation. Geological Society London Special Publications 206, 35-55.
    Plank, T., and Langmuir, C.H., 1998. The chemical composition of subducting sediment and its consequences for the crust and mantle. Chemical Geology 145, 325-394.
    Plummer, P.S., 1995. Ages and geological significance of the igneous rocks from Seychelles. Journal of African Earth Sciences 20(2), 91-101.
    Plummer, P.S., and Belle, E.R., 1995. Mesozoic tectono-stratigraphic evolution of the Seychelles microcontinent. Sedimentary Geology 96 (1), 73-91.
    Powell, C.M., Jones, D.L., Pisarevsky, S., and Wingate, M.T.D., 2001. Palaeomagnetic constraints on the position of the Kalahari craton in Rodinia. Precambrian Research 110, 33-46.
    Rabinowitz, P.D., Coffin, M.F., and Falvey, D., 1982. Salt diapirs bordering the continental margin of northern Kenya and southern Somalia. Science 215, 663-665.
    Reed, F.R.C., 1949. The geology of the British Empire, 2nd. ed., E. Arnold and Company, London, 764 p.
    Rogers, J.W., and Santosh, M., 2004. Continents and Supercontinents. Oxford, 303 p.
    Rudnick, R.L., and Fountain, D.M., 1995. Nature and composition of the continental crust - a lower crustal perspective. Reviews in Geophysics 33, 267-309.
    Rudnick, R.L., and Gao, S., 2003, Composition of the continental crust, in Rudnick R.L., ed., Treatise on Geochemistry 3, The Crust. Amsterdam, Elsevier, 1-64.
    Saha, D., and Mazumder, R., 2012. An overview of the Palaeoproterozic geology of Peninsular India, and key stratigraphic and tectonic issues. Geological Society, London, Special Publications 365, 5-29.
    Sha, L.K., and Chappell, B.W., 1999. Apatite chemical composition, determined by electron microprobe and laserablation inductively coupled plasma mass spectrometry, as a probe into granite petrogenesis. Geochimica et Cosmochimica Acta 63, 3861-3881.
    Shand, S.J., 1943. Eruptive rocks: their genesis, composition, and classification, with a chapter on meteorites. New York: J. Wiley and Sons, Inc.
    Sharma, K.K., 2005. Malani magmatism: An extensional lithospheric tectonic origin. Geological Society of America Bulletin 388, 463-476.
    Sharma, K.K., and Purohit, R., 2003. Evolution of Ur, an incipient continent to Seychelles, a micro continent from northwestern Indian Shield. International Workshop on Earth System Processes Related to Gujarat Earthquake Using Space Technology, Indian Institute of Technology, Kanpur, 85-86.
    Shellnutt, J.G, Lee, T.-Y, Chiu, H.Y., Lee, H.Y., and Jean, W., 2015. Evidence of Middle Jurassic magmatism within the Seychelles microcontinent: Implications for the breakup of Gondwana. Geophysical Research Letters 42.
    Shellnutt, J.G., Yeh, M.W., Suga, K., Lee, T.Y., Lee, H.Y., and Lin, T.H., 2017. Temporal and structural evolution of the Early Palæogene rocks of the Seychelles microcontinent. Scientific Report 7(179), 1-7.
    Sláma et al., 2008. Plesovice zircon - A new natural reference material for U-Pb and Hf isotopic microanalysis. Chemical Geology 249, 1-35.
    Srivastava, R.K., 2008. Global intracratonic boninite-notire magmatism during the Neoarchean-Paleoproterozoic: evidence from the Central Indian Bastar craton. International Geology Reviews 50, 61-74.
    Steiger, R.H., and E. Jäger, 1977. Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth and Planetary Science Letters 36, 359-362.
    Stephens, W.E., Jemielita, R.A., and Davis, D., 1997. Evidence for ca. 750 Ma intra-plate extensional tectonics from granite magmatism on the Seychelles: new geochronological data and implications for Rodinia reconstructions and fragmentation (abstract). Terra Nova 9, 166.
    Stern, R.J., 1994. Arc Assembly and continental collision in the Neoproterozoic East African orogeny - implications for the consolidation of Gondwana. Annual Review Earth Planetary Science 22, 319-351.
    Stern, R.J., 2002. Crustal evolution in the East African Orogen: a neodymium isotope
    Perspective. Journal of African Earth Sciences 34, 109-117.
    Suess, E., 1885. Das Antlitz der Erde (The Face of the Earth) (in German).
    Sun, S.S., and McDonough, W.S., 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. Geological Society, London, Special Publications 42(1), 313-345.
    Sutton, J., 1963. Long-term cycles in the evolution of the continents. Nature 19, 731-735.
    Suwa, K., Tokieda, K., and Hoshino, M., 1994. Palaeomagnetic and petrological reconstruction of the Seychelles. Precambrian Research 69, 281-292.
    Suwa, K., Yanagi, T., Tokeida, K., Umemura, H., Asami, M., and Hoshino, M., 1983. Geology and petrology of the Seychelles Islands. Preliminary Report African Studies Nagoya University 8 (Edited by Suwa, K.), 3-21.
    Taylor, H.P., 1974. A low-18O, late Precambrian granite batholith in the Seychelles Islands, Indian Ocean: evidence for formation of 18O-depleted magmas and interactions with meteoric groundwaters (abstract). Geological Society of America 6, 981-982.
    Taylor, S.R., and McLennan, S.M, 1985. The Continental Crust: its Composition and its Evolution. Blackwell, Oxford.
    Taylor, S.R., and McLennan, S.M., 1995. The geochemical evolution of the continental crust. Reviews in Geophysics 33, 241-265.
    Thomas, R.J., De Waele, B., Schofield, D.I., Goodenough, K.M., Horstwood, M., Tucker, R., Bauer, W., Annells, R., Howard, K., Walsh, G., Rabarimanana, M., Rafahatelo, J.M., Ralison, A.V., and Randriamananjara, T., 2009. Geological evolution of the Neoproterozoic Bemarivo Belt, northern Madagascar. Precambrian Research 172, 279-300.
    Torsvik, T.H., Ashwal, L.D., Tucker, R.D., and Eide, E.A., 2001a. Neoproterozoic geochronology and palaeogeography of the Seychelles microcontinent: the India link. Precambrian Research 110, 47-59.
    Torsvik, T.H., Carter, L.M., Ashwal, L.D., Bhushan, S.K., Pandit, M.K., and Jamtveit, B., 2001b. Rodinia refined or obscured: palaeomagnetism of the Malani igneous suite (NW India). Precambrian Research 108, 319-333.
    Torsvik, T.H., Tucker, R.D., Ashwal, L.D., Eide, E.A., Rakotosolofo, N.A., and De Wit, M.J., 1998. Late Cretaceous magmatism in Madagascar: palaeomagnetic evidence for a stationary Marion hotspot. Earth and Planetary Science Letters 164, 221-232.
    Tucker, R.D., Ashwal, L.D., and Torsvik, T.H., 2001. U-Pb geochronology of Seychelles granitoids: a Neoproterozoic continental arc fragment. Earth and Planetary Science Letters 187, 27-38.
    Tucker, R.D., Ashwal, L.D., Handke, M.J., Hamilton, M.A., Le Grange, M., and Rambeloson, R.A., 1999. U-Pb geochronology and isotope geochemistry of the Archean and Proterozoic rocks of north-central Madagascar. The Journal of Geology 107, 135-153.
    Umbgrove, J.H.F., 1940. Periodicity in terrestrial processes. American Journal of Science 238, 573-576.
    Wedepohl, K.H., 1995. The composition of the continental crust. Geochimica et Cosmochimica Acta 59, 1217-1232.
    Wegener, A., 1912. Die Herausbildung der Grossformen der Erdrinde (Kontinente und Ozeane), auf geophysikalischer Grundlage. Petermanns Geographische Mitteilungen 58, 185-195, 253-256, 305-309.
    Wegener, A., 1924. The Origin of Continents and Oceans. Methuen, London, 212 pp.
    Weis, D., and Deutsch, S., 1984. Nd and Pb isotope evidence from the Seychelles granites and their xenoliths: mantle origin with slight upper-crust interaction for alkaline orogenic complexes. Isotope Geoscience 2, 13-35.
    Wetherill, G.W., 1966. Radioactive decay constants and energies. In Handbook of Physical Constants. Geological Society of America 97, 514-519.
    Wetherill, G.W., 1956. An Interpretation of the Rhodesia and Witwatersrand Age Patterns. Geochimica et Cosmochimica Acta, 9, 290-292.
    Wiedenbeck, M. et al., 1995. Three Natural Zircon Standards for U-Th-Pb, Lu-Hf, Trace element and REE analysis. Geostandard Newsletters 19, 1-23.
    Wilde, S.A., Valley, J.W., Peck, W.H., and Graham, C.M., 2001. Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4 Gyr ago. Nature 409, 175-178.
    Wilson, M., 2007. Igneous Petrogenesis. Chapman and Hall, London, 411 pp.
    Windley, B.F., 1995. The Evolving Continents, Wiley, Chichester, 526 pp.
    Wood, D.A., Joron, J.L., Treuil, M., Non', M., and Tarney, J., 1979. Elemental and Sr isotope variations in basic lavas from Iceland and the surrounding ocean floor. The nature of mantle source heterogeneities. Contributions to Mineralogy and Petrology 70, 319-339.
    Worsley, T.R., Nance, R.D., and Moody, J.B., 1985. Proterozoic to recent tectonic tuning of biogeochemical cycles. In: Sunquist, E.T., Broecker, W.S. (Eds.), The Carbon Cycleand Atmospheric CO2: Natural Variations Archean to Present. Geophysical Monograph 32. American Geophysical Union, 561-572.
    Yanagi, T., Wakizaka, Y., and Suwa, K., 1983. Rb-Sr whole rock ages of granitic rocks from the Seychelles Islands, 8th Prelim. Rept. Afr. Studies, Nagoya University, 23-36.
    Zhao, G.C, Cawood, A.P., Wilde, A.S., and Sun, M., 2002. Review of global 2.1-1.8 Ga orogens: implications for a pre-Rodinia supercontinent. Earth Science Reviews 59, 125-162.
    Zhao, G.C, Sun, M., Wilde, S.A., and Li, S.Z., 2004. A Paleo-Mesoproterozoic supercontinent: assembly, growth and breakup. Earth Science Reviews 67(1-2), 91-123.
    Zhou, J.L., Li, X.H., Tang, G.Q., Li, Y., and Tucker, R.D., 2018. New evidence for a continental rift tectonic setting of the Neoproterozoic Imorona-Itsindro Suite (central Madagascar). Precambrian Research 306, 94-111.
    Zhou, J.L., Shao, S., Luo, Z.H., Shao, J.B., Wu, D.T., and Rasoamalala, V., 2015. Geochronology and geochemistry of Cryogenian gabbros from the Ambatondrazaka area, east-central Madagascar: implications for Madagascar-India correlation and Rodinia paleogeography. Precambrian Research 256, 256-270.
    Zhu, D.C., Mo, X.X, Wang, L.Q., Zhao, Z.D., Niu, Y.L., Zhou, C.Y., and Yang, Y.H., 2009. Petrogenesis of highly fractionated I-type granites in the Zayu area of eastern Gangdese, Tibet: Constraints from zircon U-Pb geochronology, geochemistry and Sr-Nd-Hf isotopes. Science in China press, Springer.

    下載圖示
    QR CODE