{"references": ["J. D. Blum , D. A. Papanastassiou, C. Koeberl, and G. J. Wasserburg, \"Nd\nand Sr isotopic study of Australasian tektites:New constraints on the\nprovenance and age of target material\", Geochim. Cosmochim. Acta, 56,\npp. 483-492, 1992.", "K. S. Ho, and J. C. Chen, \"Geochemistry and origin of tektites from the\npenglei area, Hainan province, southern China.\" J. of Southeast Asian\nEarth Sciences Vol. 13, No. 1, pp. 61-72, 1996.", "B. P. Glass, \"Tektites and microtektites: key facts and inferences.\"\nTectonophysics 171, pp. 393-404, 1990.", "C. Koeberl, \"Tektite origin by hypervelocity asteroidal or cometary\nimpact:Target rocks, source craters, and mechanisms.\" Geol. Soc. Am.\nSpecial Paper 293, pp. 133-151, 1994.", "A. Montanari, and C. Koeberl, \"Impact Stratigraphy: The Italian Record.\"\nSpringer, Heideberg, 2000.", "P. Ma, K. Aggrey, C. Tonzola, C. Schnabel, P. De Nicola, G. F. Herzog, J.\nT. Wasson, B. P. Glass, L. Brown, F. Tera, R. Middleton and J. Klein,\n\"Beryllium-10 in Australasian tektites: constraints on the locateon of the\nsource crater.\" Geochim. Cosmochim. Acta 68, pp. 3883-3896, 2004.", "F. Serefiddin, G. F. Herzog, C. Koeberl, \"Beryllium-10 concentrations of\ntektites from the Ivory Coast and from Central Europe: evidence for\nnear-surface residence of precursor materials.\" Geochim. Cosmochim.\nActa 71, pp. 1574-1582, 2007.", "C. Koeberl, \"The geochemistry and cosmochemistry of impacts.\" In:\nDavis, A. (Ed.), Treatise of Geochemistry, vol. 1. Elsevier, pp.\n1.28.1-1.28.52, 2007.", "F. Moynier, P. Beck, F. Jourdan, Q. Z. Yin, U. Reimold, and C. Koeberl,\n\"Isotopic fractionation of zinc in tektites.\" Earth and Planetary Science\nLetters, 277, pp. 482-489, 2009.\n[10] B. P. Glass, H. Huber and C. Koeberl \"Geochemistry of Cenozoic\nmicrotektites and clinopyroxene-bearing sphereules.\" Geochim.\nCosmochim. Acta 68, pp. 3971-4006, 2004.\n[11] G. A. Izett, and J. D. Obradovich, \"Laser-fusion 40Ar/39Ar ages of\nAustralasian tektites (abstract)\", Lunar Planet. Sci., 23, 1992.\n[12] J. Kunz, K. Bollinger, E. K. Jessberger, and D. Storzer, \"Ages of\nAustralasian tektites (abstract)\". Lunar Planet. Sci. XXVI, pp. 809-810,\n2000.\n[13] H. Yamei, R. Potts, Y. Baoylin, G. Zhengtang, A. Deino, W. Wei, J.\nClark, X. Guangmao, and H. Weiwen, \"Mid-Pleistocene Acheulean-like\nstone technology of the Bose Basin, South China.\" Science 287, pp.\n1622-1626, 2000.\n[14] Y. T. Lee, J. C. Chen, K. S. Ho and W. S. Juang, \"Geochemical studies of\ntektites from East Asia.\" Geochem. Jour. 38, pp. 1-17, 2004.\n[15] C. Koeberl, C. W. Poag, W. U. Reimold, and D. Brandt, \"Impact origin of\nChesapeak Bay structure and the source of North American tektites.\"\nScience 271, pp. 1263-1266, 1996.\n[16] B. P. Glass and J. E. Pizzuto, \"Geographical variation in Australasian\nmicrotektite concentrations: Implications concerning the location and size\nof the source crater.\" J. Geophys. Res. 99, pp. 19075-19081, 1994.\n[17] C. Koeberl, \"Geochemistry and origin of Muong Nong-type tektites.\"\nGeochim. Cosmochim. Acta 56, pp. 1033-1064, 1992.\n[18] C. Koeberl, F. Kluger and W. Kiesl, \"Geochemistry of Muong Nong-type\ntektites V: unusual ferric/ferrous ratio.\" Meteoritics 19, pp. 253-254,\n1984.\n[19] P. H. Stauffer, \"Anatomy of the Australasian tektite strewn field and the\nprobable site of its source crater.\" In Proceedings of the 3rd Regional\nConference on Geology and Mineral Resources of Southeast Asia,\nBangkok, Thailand. pp. 285-289, 1978.\n[20] J. B. Hartung and A. R. Rivolo, \"A possible source in Cambodia for\nAustralasian tektites.\" Meteoritics 14, pp. 153-159, 1979.\n[21] R. A. Dunlap and A. D. E. Sibley, \"A Mossbauer effect study of Fe-site\noccupancy in Australasian tektites.\" J. Non-Cryst. Solids 337,pp.36-41,\n2004.\n[22] C. Koeberl, \"Geochemistry of tektites and impact glasses an overview.\"\nAnnual Review of Earth and Planetary Sciences, 14, pp. 325-350, 1986.\n[23] S. M. Mclennan, and S. R. Taylor, \"Th and U in sedimentary rocks: crustal\nevolution and sedimentary recyling.\" Nature 285, pp. 621-624, 1985.\n[24] T. Sato, \"Regional geology and stratigraphy : Southeast Asia and Japan.\"\nIn The Jurassic of the Circum-Pacific(Edited by Westermann G. E. G.),\npp. 194-213. Cambridge University Press, 1992.\n[25] K. C. Condie, \"Chemical composition and evolution of the upper\ncontinental crust: Contrasting results from surface samples and shales.\"\nChem. Geol. 104, pp. 1-37, 1993."]}

Twenty seven tektites from the Wenchang area, Hainan province (south China) and five tektites from the Khon Kaen area (northeast Thailand) were analyzed for major and trace element contents and Rb-Sr isotopic compositions. All the samples studied are splash-form tektites. Tektites of this study are characterized by high SiO2 contents ranging from 71.95 to 74.07 wt% which is consistent with previously published analyses of Australasian tektites. The trace element ratios Ba/Rb (avg. 3.89), Th/Sm (avg. 2.40), Sm/Sc (avg. 0.45), Th/Sc (avg. 0.99) and the rare earth elements (REE) contents of tektites of this study are similar to the average upper continental crust. Based on the chemical composition, it is suggested that tektites in this study are derived from similar parental material and are similar to the post-Archean upper crustal rocks. The major and trace element abundances of tektites analyzed indicate that the parental material of tektites may be a terrestrial sedimentary deposit. The tektites from the Wenchang area, Hainan Island have high positive εSr(0) values-ranging from 184.5~196.5 which indicate that the parental material for these tektites have similar Sr isotopic compositions to old terrestrial sedimentary rocks and they were not dominantly derived from recent young sediments (such as soil or loess). Based on Rb-Sr isotopic data, it has been suggested by Blum (1992) [1]that the depositional age of sedimentary target materials is close to 170Ma (Jurassic). According to the model suggested by Ho and Chen (1996)[2], mixing calculations for various amounts and combinations of target rocks have been carried out. We consider that the best fit for tektites from the Wenchang area is a mixture of 47% shale, 23% sandstone, 25% greywacke and 5% quartzite, and the other tektites from Khon Kaen area is a mixture of 46% shale, 2% sandstone, 20% greywacke and 32% quartzite.