Mapping Chicxulub crater structure with gravity and seismic reflection data

Geological Society Special Publication

Volumn 140, Issue , 1998, Pages 155-176

  Hildebrand, A R ^a   Pilkington, M ^a   Ortiz Aleman, C ^b   Chavez, R E ^b   Urrutia Fucugauchi, J ^b   Connors, M ^c   Graniel Castro, E ^d   Camara zi, A ^d   Halpenny, J F ^e   Niehaus, D ^f  

^a GEOLOGICAL SURVEY OF CANADA   (Canada)

^b UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO   (Mexico)

^c ATHABASCA UNIVERSITY   (Canada)

^d UNIVERSIDAD AUTÓNOMA DE YUCATÁN   (Mexico)

^e Geomatics Canada   (Canada)

^f PCI Enterprises   (Canada)

Author keywords

[No Author keywords available]

Indexed keywords

CRATER; GRAVITY SURVEY; IMPACT STRUCTURE; MAPPING; MASS EXTINCTION; SEISMIC REFLECTION;

MEXICO;

EID: 0032323353     PISSN: 03058719     EISSN: None     Source Type: Book Series    
DOI: 10.1144/GSL.SP.1998.140.01.12     Document Type: Article

References (110)

1. ADUSHKIN, V. V. & NEMCHINOV, I. I. 1994. Consequences of impacts of cosmic bodies on the surface of the Earth. In: GEHRELS, T. (ed.) Hazards due to Comets and Asteroids. University of Arizona Press, Tucson, Arizona, 721-778.
2. AHRENS, T. J. & O'KEEFE, J. D. 1983. Impact of an asteroid or comet in the ocean and extinction of terrestrial life. In: Proceedings of the 13th Lunar and Planetary Science Conference, Part 2, Journal of Geophysical Research, 88, A799-A806.
3. ALVAREZ, L. W., ALVAREZ, W., ASARO, F. & MICHEL, H. 1980. Extraterrestrial cause for the Cretaceous/ Tertiary extinction. Science, 208, 1095-1108.
4. ANDERS, E. & GREVESSE, N. 1989. Abundances of the elements: Meteoritic and solar. Geochimica et Cosmochimica Acta, 53, 2363-2380.
5. ASPHAUG, E. & BENZ, W. 1994. Density of comet Shoemaker-Levy 9 deduced by modelling breakup of the parent 'rubble pile'. Nature, 370, 120-124.
6. _, MOORE, J. M., MORRISON, D., BENZ, W., NOLAN, M. C. & SULLIVAN, R. J. 1996. Mechanical and geological effects of impact cratering on Ida. Icarus, 120, 158-184.
7. 2 over Phanerozoic time. American Journal of Science, 294, 56-91.
8. BLAKELY, R. J. & SIMPSON, R. W. 1986. Approximating edges of source bodies from magnetic or gravity anomalies. Geophysics, 51, 1494-1498.
9. BOHOR, B. F., MODRESKI, P. J. & FOORD, E. E. 1987. Shocked quartz in the Cretaceous-Tertiary boundary clays: Evidence for a global distribution. Science, 236, 705-709.
10. BORG, I. Y. 1972. Some shock effects in granodiorite to 270 kilobars at the Pile Driver site. Flow and Fracture in Rocks. American Geophysical Union Monograph, 16, 293-311.
11. BOURGEOIS, J., HANSEN, T. A., WILBERG, P. L. & KAUFFMAN, E. G. 1988. A tsunami deposit at the Cretaceous-Tertiary boundary in Texas. Science, 241, 567-570.
12. BRETT, R. 1992. The Cretaceous-Tertiary extinction: A lethal mechanism involving anhydrite target rocks. Geochimica et Cosmochimica Acta, 56, 3603-3606.
13. CAMARGO ZANOGUERA, A. & SUÁREZ REYNOSO, G. 1994. Evidencia sismica del crater de impacto de Chicxulub. Boletín de la Asociación Mexicana de Géofisicos de Exploracion, 34, 1-28.
14. CAMPOS-ENRIQUEZ, J. O., ARZATE, J. A., URRUTIA-FUCUGAUCHI, J. & DELGADO-RODRIGUEZ 1997. The subsurface structure of the Chicxulub crater (Yucatán, México): Preliminary results of a magnetotelluric study. The Leading Edge, 16, 1774-1777.
15. CARLSON, R. W., WEISSMAN, P. R., SEGURA, M., HUI, J., SMYTHE, W. D., JOHNSON, T. V. & BAINES, K. H. 1995. Galileo infrared observations of the Shoemaker-Levy 9 G impact fireball: A preliminary report. Geophysical Research Letters, 22, 1557-1560.
16. _, DROSSART, P., ENCRENAZ, TH., WEISSMAN, R., HUI, J. & SEGURA, M. 1997. Temperature, size and energy of the Shoemaker-Levy 9 G-impact fireball. Icarus, 128, 251-274.
17. CHRISTESON, G. L., NAKAMURA, Y., BUFFLER, R. T. & CHICXULUB WORKING GROUP 1997. Structure of the Chicxulub crater from wide-angle OBS data: Evidence for a multi-ring impact basin. Eos, Transactions, American Geophysical Union, 78, F399.
18. COLGATE, S. A. & PETSCHEK, A. G. 1984. Cometary impacts and global distributions of resulting debris by floating. LA-UR-84-3911, Los Alamos National Laboratory, Los Alamos, NM, 17.
19. CONNORS, M., HILDEBRAND, A. R., PILKINGTON, M., ORTIZ-ALEMAN, C., CHAVEZ, R. E., URRUTIA-FUCUGAUCHI, J., GRAMEL-CASTRO, E., CAMARAZI, A., VASQUEZ, J. & HALPENNY, J. F. 1996. Yucatan karst features and the size of Chicxulub Crater. Geophysical Journal International, 127, F11-F14.
20. COVEY, C., GHAN, S. J., WALTON, J. J., WEISSMAN, P. R. 1990. Global environmental effects of impact-generated aerosols: Results from a general circulation model. In: SHARPTON, V. L. & WARD, P. D. (eds) Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America Special Paper, 247, 391-400.
21. CROFT, S. K. 1980. Cratering flow fields: Implications for the excavation and transient expansion stages of crater formation. Proceedings of the Eleventh Lunar and Planetary Science Conference, Geochimica et Cosmochimica Acta, Supp., 14, 2347-2378.
22. _ 1985. The scaling of complex craters. Proceedings of the 15th Lunar and Planetary Science Conference, Part 2, Journal of Geophysical Research, 90, Supplement, C828-C842.
23. D'HONDT, S., PILSON, M. E. Q., SIGURDSSON, H., HANSON, A. K. JR. & CAREY, S. 1994. Surface-water acidification and extinction at the Cretaceous-Tertiary boundary. Geology, 22, 983-986.
24. _, KING, J. & GIBSON, C. 1996. Oscillatory marine response to the Cretaceous-Tertiary impact. Geology, 24, 611-614.
25. DELSEMME, A. H. 1988. The chemistry of comets. Philosophical Transactions of the Royal Society of London, A325, 509-523.
26. DENCE, M. R., GRIEVE, R. A. F. & ROBERTSON, B. 1977. Terrestrial impact structures: Principal characteristics and energy considerations: In: RODDY, D. J., PEPIN, R. O. & MERRILL, R. B. (eds) Impact and Explosion Cratering. Pergamon, New York, 247-275.
27. DYPVIK, H., GUDLAUGSSON, S. T., TSIKALAS, F., ATTREP, M. JR., FERRELL, R. E. JR., KRINSLEY, D. H., MORK, A., FALEIDE, J. I. & NAGY, J. 1996. Mjolnir structure: An impact crater in the Barents Sea. Geology, 24, 779-782.
28. EMILIANI, C., KRAUS, E. B. & SHOEMAKER, E. M. 1981. Sudden death at the end of the Mesozoic. Earth and Planetary Science Letters, 55, 317-334.
29. 3He in seafloor sediments: A comparison of the Eocene/Oligocene and Cretaceous/Tertiary boundaries. Eos, Transactions, American Geophysical Union, 78, F371.
30. GALLAGHER, W. B. 1991. Selective extinction and survival across the Cretaceous/Tetiary boundary in the northern Atlantic Coastal Plain. Geology, 19, 967-970.
31. GAULT, D. E. & WEDEKIND, J. A. 1978. Experimental studies of oblique impact. Proceedings of the Ninth Lunar and Planetary Science Conference, 3, 3843-3875.
32. GILMOUR, I., WOLBACH, W. S. & ANDERS, E. 1990. Early environmental effects of the terminal Cretaceous impact. In: SHARPTON, L. & WARD, D. (eds) Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America Special Paper, 247, 391-400.
33. GRIEVE, R. A. F. 1982. The record of impact on Earth: Implications for a major Cretaceous/Tertiary impact event. In: SILVER, L. T. & SCHULTZ, P. H. (eds) Geological Implications of Impacts of Large Asteroids and Comets on the Earth. Geological Society of America Special Paper, 190, 25-37.
34. _, ROBERTSON, P. B. & DENCE, M. R. 1981. Constraints on the formation of ring impact structures, based on terrestrial data, Multi-ring Basins. Proceedings of Lunar and Planetetary Science, 12A, 37-57.
35. HANSEN, T., FARRAND, R. B., MONTGOMERY, H. A., BILLMAN, H. G. & BLECHSCHMIDT, G. 1987. Sedimentology and extinction patterns across the Cretaceous-Tertiary boundary internal in east Texas. Cretaceous Research, 8, 229-252.
36. HILDEBRAND, A. R. 1992. Geochemistry and stratigraphy of the Cretaceous/Tertiary boundary impact ejecta. PhD dissertation, University of Arizona.
37. _ 1993. The Cretaceous/Tertiary boundary impact (or the dinosaurs didn't have a chance). Journal of the Royal Astronomical Society of Canada, 87, 77-118.
38. _ 1997. Contrasting Chicxulub Crater structural models: What can seismic velocity studies differentiate? Journal of Conference Proceedings, 1, 37-46.
39. _ & BOYNTON, W. V. 1989. Hg anomalies at the K/ T boundary: Evidence for acid rain? Meteoritics, 24, 277-278.
40. _ & _ 1990. Proximal Cretaceous-Tertiary Boundary Impact Deposits in the Caribbean. Science, 248, 843-847.
41. _ & WOLBACH, W. S. 1989. Carbon and chalcophiles at a nonmarine K/T boundary: Joint investigations of the Raton section, New Mexico, Lunar and Planetary Science, XX, 414-415. The Lunar and Planetary Science Institute, Houston.
42. _, PENFIELD, G. T., KRING, D. A., PILKINGTON, M., CAMARGO, Z. A., JACOBSEN, S. & BOYNTON, W. 1991. Chicxulub crater: A possible Cretaceous-Tertiary boundary impact crater on the Yucatán Peninsula, México. Geology, 19, 867-871.
43. _, CONNORS, M., PILKINGTON, M., ORTIZ ALEMAN, C. & CHAVEZ, R. E. 1994. Size and structure of the Chicxulub crater. Revista de la Sociedad Mexicana de Paleontologia, 7, 1, 59-68.
44. _, PILKINGTON, M., CONNORS, M., ORTIZ-ALEMAN, C. & CHAVEZ, R. E. 1995. Size and structure of the Chicxulub crater revealed by horizontal gravity gradients and cenotes. Nature, 376, 415-417.
45. _, _, HALPENNY, J. F., COOPER, R. V., CONNORS, M., ORTIZ-ALEMAN, C., CHAVEZ, R. E., URRUTIA-FUCUGAUCHI, J., GRANIEL-CASTRO, E., CAMARAZI, A. & BUFFLER, R. T. 1997. The Chicxulub crater as revealed by gravity and seismic surveys. Eos, Transactions, American Geophysical Union, 78, F398.
46. HSU, K. J., HE, Q., MCKENZIE, J. A., WEISSERT, H., PERCH-NIELSEN, K., OBERHANSLI, H., KELTS, K., LABREQUE, J., TAUXE, L., KRAHENBUHL, U., PERCIVAL, S. F., WRIGHT, R., KARPOFF, A. M., PETERSEN, N., TUCKER, P., POORE, R. Z., GOMBOS, A. M., PISCIOTTO, K., CARMAN, M. F. JR. & SCHREIBER, E. 1982. Mass mortality and its environmental and evolutionary consequences. Science, 216, 249-256.
47. ISAAC, J. H. & STEWART, R. R. 1993. 3-D seismic expression of a cryptoexplosion structure. Canadian Journal of Exploration Geophysics, 29, 429-439.
48. IVANOV, B. A., BADUKOV, D. D., YAKOVLEV, O. I., GERASIMOV, M. V., DIKOV, YU, P., POPE, K. O. & OCAMPO, A. C. 1996. Degassing of sedimentary rocks due to Chicuxlub impact: Hydrocode and physical simulations. In: RYDER, G., FASTOVSKY, D. & GARTNER, S. (eds) The Cretaceous-Tertiary Event and other Catastrophes in Earth History. Geological Society of America Special Paper, 307, 125-139.
49. IZETT, G. A. 1990. The Cretaceous/Tertiary boundary interval, Raton Basin, Colorado and New Mexico, and its content of shock-metamorphosed minerals; Evidence relevant to the K-T boundary impact-extinction theory. Geological Society of America Special Paper, 249.
50. JABLONSKI, D. 1986. Background and mass extinctions: The alternation of macroevolutionary regimes. Science, 231, 129-133.
51. JESSBERGER, E. K., CHRISTOFORIDIS, A. & KISSEL, J. 1988. Aspects of the major element composition of Halley's dust. Nature, 332, 691-695.
52. JIANG, M. J. & GARTNER, S. 1986. Calcareous nonnofossil succession across the Cretaceous/Tertiary boundary in east-central Texas. Micropaleontology, 32, 232-255.
53. KELLER, G. 1989. Extended Cretaceous/Tertiary boundary extinctions and delayed population change in planktonic foraminifera from Brazos River, Texas. Paleooceanography, 4, 3, 287-332.
54. KINSLAND, G., HURTADO, M., CERON, A., SMYTHE, W., OCAMPO, A. & POPE, K. 1995. New gravity data over the southwestern portion of the Chicxulub impact feature, Yucatán Peninsula, México. Lunar and Planetary Science XXIII, 755-756. The Lunar and Planetary Science Institute, Houston.
55. KRING, D. A., MELSOH, H. J. & HUNTEN, D. M. 1996. Impact-induced perturbations of atmospheric sulfur. Earth and Planetary Science Letters, 140, 201-212.
56. KYTE, F. T., SMIT, J. & WASSON, J. T. 1985. Siderophile interelement variations in the Cretaceous-Tertiary boundary sediments from Caravaca, Spain. Earth and Planetary Science Letters, 73, 183-195.
57. _, BOSTWICK, J. A. & ZHOU, L. 1996. The Cretaceous-Tertiary boundary on the Pacific plate: Composition and distribution of impact debris. In: RYDER, G., FASTOVSKY, D. & GARTNER, S. (eds) The Cretaceous-Tertiary Event and other Catastrophes in Earth History. Geological Society of America Special Paper, 307, 389-401.
58. LERBEKMO, J. F. & ST. LOUIS, R. M. 1986. The terminal Cretaceous iridium anomaly in the Red Deer Valley, Alberta, Canada. Canadian Journal of Earth Science, 23, 120-124.
59. LEWIS, J. S., WATKINS, G. H., HARTMAN, H. & PRINN, R. G. 1982. Chemical consequences of major impact events on earth. In: SILVER, L. T. & SCHULTZ, H. (eds) Geological Implications of Impacts of Large Asteroids and Comets on the Earth. Geological Society of America Special Paper, 190, 215-221.
60. LOPEZ RAMOS, E. 1975. Geological summary of the Yucatán Peninsula. In: NAIRN, A. E. M. & STEHLI, F. G. (eds) The Ocean Basins and Margins, Vol. 3 -The Gulf of Mexico and the Caribbean. Plenum, New York, 257-282.
61. DE MAUPERTUIS, L. M. 1750. Essay de Cosmologie, in Les Oeuvres de Mr. De Maupertuis, 1752, Dresden, Libraire du Roy, 1-54.
62. MCGETCHIN, T. R., SETTLE, M. & HEAD, J. W. 1973. Radial thickness variation in impact crater ejecta: Implications for lunar basin deposits. Earth and Planetary Science Letters, 20, 226-236.
63. MCKAY, C. & THOMAS, G. E. 1982. Formation of noctilucent clouds by an extraterrestrial impact. In: SILVER, L. T. & SCHULTZ, H. (eds) Geological Implications of Impacts of Large Asteroids and Comets on the Earth. Geological Society of America Special Paper, 190, 211-214.
64. MELOSH, H. J. 1989. Impact Cratering: A Geologic Process. Oxford University Press.
65. _, SCHNEIDER, N. M., ZAHNLE, K. J. & LATHAM, D. 1990. Ignition of global wildfires at the Cretaceous Tertiary boundary. Nature, 343, 251-254.
66. MORGAN, J., WARNER, M., BRITTAN, J., BUFFLER, R., CAMARGO, A., CHRISTESON, G., DENTON, P., HILDEBRAND, A., HOBBS, R., MACINTYRE, H., MACKENZIE, G., MAGUIRE, P., MARIN, L., NAKAMURA, Y., PILKINGTON, M., SHARPTON, V. L., SNYDER, D., SUAREZ, G., TREJO, A. 1997. Size and morpholosy of the Chicxulub impact crater. Nature, 390, 472-476.
67. NESS, G. E., DAUPHIN, J. P., GARCIA-ABDESLEM, J. & ALVARADO-OMANA, M. E. 1991. Bathymetry and Gravity and Magnetic Anomalies of the Yucatán Peninsula and Adjacent Areas. Geological Society of America Map and Chart Series MCH073.
68. OFFIELD, T. W. & POHN, H. A. 1977. Deformation at the Decaturville impact structure, Missouri: In: RODDY, D. J., PEPIN, R. O. & MERRILL, R. B. (eds) Impact and Explosion Cratering. Pergamon, New York, 321-341.
69. O'KEEFE, J. D. & AHRENS, T. J. 1982. The interaction of the Cretaceous/Tertairy Extinction Bolide with the atmosphere, ocean and solid Earth. In: SILVER, L. T. & SCHULTZ, P. H. (eds) Geological Implications of Impacts of Large Asteroids and Comets on the Earth. Geological Society of America Special Paper, 190, 103-120.
70. 2 by the Cretaceous/Tertiary extinction bolide and the resultant heating of the Earth. Nature, 338, 247-249.
71. OPIK, E. J. 1958. On the catastrophic effects of collisions with celestial bodies. Irish Astronomical Journal, 5, 34-35.
72. ORTH, C. J., GILMORE, J. S. & KNIGHT, J. D. 1987. Iridium anomaly at the Cretaceous-Tertiary boundary in the Raton Basin, New Mexico Geological Society 38th Annual Field Conference Guidebook, 265-270.
73. _, ATTREP, M. JR & QUINTANA, L. R. 1990. Iridium abundance patterns across bio-event horizons in the fossil record. In: SHARPTON, V. L. & WARD, P. D. (eds) Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America Special Paper, 247, 45-59.
74. PERRY, E. C., MARIN, L., MCCLAIN, J. & VELÁQUEZ, G. 1995. Ring of Cenotes (sinkholes), northwest Yucatan, Mexico: Its hydrogeologic characteristics and possible association with the Chicxulub impact crater. Geology, 23, 17-20.
75. PILKINGTON, M. & GRIEVE, R. A. F. 1992. The geophysical signature of impact craters. Reviews of Geophysics, 30, 161-181.
76. _, HILDEBRAND, A. R. & ORTIZ ALEMAN, C. 1994. Gravity and magnetic field modeling and structure of the Chicxulub crater, Mexico. Journal of Geophysical Research, 99, 13 147-13 162.
77. PIKE, R. J. 1985. Some morphologic systematics of complex impact structures. Meteoritics, 20, 49-68.
78. POPE, K., O., OCAMPO, A. C. & DULLER, C. E. 1993. Surficial geology of the Chicxulub impact crater, Yucatán, México. Earth, Moon and Planets, 63, 93-104.
79. _, BAINES, K. H., OCAMPO, A. C. & IVANOV, B. A. 1994. Impact winter and the Cretaceous/Tertiary extinctions. Results of a Chicxulub asteroid impact model. Earth and Planetary Science Letters, 128, 719-725.
80. _, OCAMPO, A. C., KINSLAND, G. L., SMITH, R. 1996. Surface expression of the Chicxulub crater. Geology, 24, 527-530.
81. PRINN, R. G. & FEGLEY, B. 1987. Bolide impacts, acid rain, and biospheric traumas at the Cretaceous-Tertiary boundary. Earth and Planetary Science Letters, 83, 1-5.
82. RUSSELL, D. A. 1979. The enigma of the extinction of the dinosaurs. Annual Review of Earth and Planetary Science, 7, 163-182.
83. SCHMIDT, R. M. & HOUSEN, K. R. 1987. Some recent advances in the scaling of impact and explosion cratering. International Journal of Impact Engineering, 5, 543-560.
84. SHARPTON, V. L., BURKE, K., CAMARGO-ZANOGUERA, A., HALL, S. A., LEE, D. S., MARIN, L. E., SUÁREZ-REYNOSO, G., QUEZADA-MUZETON, J. M., SPUDIS, D. & URRUTIA-FUCUGAUCHI, J. 1993. Chicxulub multi-ring impact basin: Size and other characteristics derived from gravity analysis. Science, 261, 1564-1567.
85. _, MARIN, L. E., CARNEY, J. L., LEE, S., RYDER, G., SCHURAYTZ, B. C., SIKORA, P., SPUDIS, P. D. 1996. A model of the Chicxulub impact basin based on evaluation of geophysical data, well logs, and drill core samples. In: RYDER, G., FASTOVSKY, D. & GARTNER, S. (eds) The Cretaceous-Tertiary Event and other Catastrophes in Earth History. Geological Society of America Special Paper, 307, 55-74.
86. SHEEHAN, P. M. & HANSEN, T. A. 1986. Detritus feeding as a buffer to extinction at the end of the Cretaceous. Geology, 14, 868-870.
87. SHOEMAKER, E. M., PILLMORE, C. L. & PEACOCK, E. W. 1987. Remanent magnetization of rocks of latest Cretaceous and earliest Tertiary age from drill core at York Canyon, New Mexico. In: FASSETT, J. E. & RIGBY, J. K. JR. (eds) The Cretaceous-Tertiary Boundary in the San Juan and Raton Basins, New Mexico and Colorado. Geological Society of America Special Paper, 209, 131-150.
88. _, WOLFE, R. F. & SHOEMAKER, C. S. 1990. Asteroid and comet flux in the neighbourhood of Earth. In: SHARPTON, V. L. & WARD, P. D. (eds) Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America Special Paper, 247, 155-170.
89. SIGURDSSON, H., D'HONDT, S. & CAREY, S. 1992. The impact of the Cretaceous/Tertiary bolide on evaporite terrane and generation of major sulfuric acid aerosol. Earth and Planetary Science Letters, 109, 543-559.
90. SMIT, J. 1990. Meteorite impact, extinctions and the Cretaceous-Tertiary Boundary. Geologie en Mijnbouw, 69, 187-204.
91. _ 1994. Extinctions at the Cretaceous-Tertiary boundary: The link to the Chicxulub impact. In: GEHRELS, T. (ed.) Hazards due to Comets and Asteroids. University of Arizona Press, Tucson, Arizona, 859-878.
92. _ & ROMEIN, A. J. T. 1985. A sequence of events across the Cretaceous-Tertiary boundary. Earth and Planetary Science Letters, 74, 155-170.
93. _, ALVAREZ, W., MONTANARI, A., SWINBOURNE, N. H. M., VAN KEMPEN, T. M., KLAVER, G. T. & LUSTENHOUWER, W. J. 1992. 'Tektites' and microcrystites at the Cretaceous Tertiary boundary: Two strewn fields, one crater? Proceedings of Lunar and Planetary Science, 22, 87-100.
94. _, ROEP, TH. B., ALVAREZ, W., MONTANARI, A., CLAEYS, P., GRAJALES-NISHIMURA, J. M. & BERMUDEZ, J. 1996. Coarse-grained, clastic sandstone complex at the K/T boundary around the Gulf of Mexico: Deposition by tsunami waves induced by the Chicxulub impact? In: RYDER, G., FASTOVSKY, D. & GARTNER, S. (eds) The Cretaceous-Tertiary Event and other Catastrophes in Earth History. Geological Society of America Special Paper, 307, 151-182.
95. SWEET, A. R. 1994. Relationships between depositional environments and changes in palynofloras across the K/T boundary interval, In: TRAVERSE, A. (ed.) Sedimentation of Organic Particles. Cambridge University Press, 461-488.
96. _ & BRAMAN, D. R. 1992. The K-T boundary and contiguous strata in western Canada: interactions between paleoenvironments and palynological assemblages. Cretaceous Research, 13, 31-79.
97. THERRIAULT, A, M., GRIEVE, R. A. F. & REIMOLD, W. U. 1997. Original size of the Vredefort structure: implications for the geological evolution of the Witwatersrand Basin. Meteoritics and Planetary Science, 32, 71-77.
98. TOON, O. B., POLLACK, J. B., ACKERMAN, T. P., TURCO, R. P., MCKAY, C. P. & LIU, M. S. 1982. Evolution of an impact-generated dust cloud and its effects on the atmosphere. In: SILVER, L. T. & SCHULTZ, P. H. (eds) Geological Implications of Impacts of Large Asteroids and Comets on the Earth. Geological Society of America Special Paper, 190, 187-200.
99. _, ZAHNLE, K., MORRISON, D., TURCO, R. P. & COVEY, C. 1997. Environmental perturbations caused by the impacts of asteroids and comets. Reviews of Geophysics, 35, 41-78.
100. TURCOTTE, D. L. & SCHUBERT, G. 1982. Geodynamics: Applications of Continuum Physics to Geological Problems. Wiley, New York.
101. URRUTIA-FUCUGAUCHI, J., MARIN, L. & TREJO GARCIA, A. 1996. Initial results of the UNAM scientific drilling program on the Chicxulub impact structure: Rock magnetic properties of UNAM-7 Tekax borehole. Geofisica Internacional, 35, 125-133.
102. VENKATESAN, M. I. & DAHL, J. 1989. Further geochemical evidence for global fires at the Cretaceous-Tertiary boundary. Nature, 338, 57-60.
103. VILLAGOMEZ, A. 1953. Un programa de exploracion para la Peninsula de Yucatan. Boletin de la Asociacion Mexicana de Geologos Petroleros, 5, 77-84.
104. WARD, W. C., KELLER, G., STINNESBECK, W. & ADATTE, T. 1995. Yucatán subsurface stratigraphy: Implications and constraints for the Chicxulub impact. Geology, 23, 873-876.
105. WEISSMAN, P. R. 1990. The cometary impactor flux at the Earth. In: SHARPTON, V. L. & WARD, P. D. (eds) Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America Special Paper, 247, 171-179.
106. WOLBACH, W. S., LEWIS, R. S. & ANDERS, E. 1985. Cretaceous extinctions: evidence for wildfires and search for meteoritic material. Science, 230, 167-170.
107. _, GILMOUR, I., ANDERS, E., ORTH, C. J. & BROOKS, R. R. 1988. Global fire at the Cretaceous-Tertiary boundary. Nature, 334, 665-669.
108. _, _ & _ 1990. Major wildfires at the Cretaceous/Tertiary boundary: In: SHARPTON, V. L. & WARD, P. D. (eds) Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America Special Paper, 247, 391-400.
109. ZACHOS, J. C. & ARTHUR, M. A. 1986. Paleoceanography of the Cretaceous/Tertiary boundary event: Inferences from stable isotopic and other data. Paleoceanography, 1, 5-26.
110. ZAHNLE, K. J. 1990. Atmospheric chemistry by large impacts. In: SHARPTON, V. L. & WARD, P. D. (eds) Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America Special Paper, 247, 271-288.