Mechanismen der Zielgesteinsdeformation während der Peakring-Bildung
Zusammenfassung der Projektergebnisse
Crater floors of large terrestrial impact structures, also known as impact basins, are largely flat and dissected by two or more morphological rings. The formation of the innermost ring, the socalled peak ring, and causes of target rock weakening leading to flat crater floors are still unknown. Unravelling these mechanisms were the prime structural geological objectives of Expedition 364 “Drilling the K-Pg Impact Crater” and this project using the Chicxulub impact structure, Mexico, as a terrestrial analogue for the formation of planetary impact basins. The project furnished structural geologic proof for the validity of the acoustic fluidization hypothesis formulated more than 40 years ago by the late H. Jay Melosh. This hypothesis calls for a transient fluid-like behaviour of impacted rock during cratering, which enabled the formation of impact craters, hundreds of kilometres in diameter, within less than 10 minutes. Project results not only identified the respective rock deformation mechanism that weakened the rock; the results also explain, for the first time, the presence of flat crater floors dissected by central peaks and morphological rings. Furthermore, the project revealed also unprecedented evidence for the interaction of molten rock, which covered the crater floor immediately after cratering, with rock-debris laden seawater entering the crater within about an hour after impact. Finally, micro-tomography demonstrated that impacted rock contains up to 13% of open pores, which seem to be connected to each other by small channels. These results have important ramifications for the possible origin of life in large impact craters on the Early Earth and other planets. In summary, we contributed significantly to our understanding on the formation mechanisms of large impact craters and their peak rings, the dynamics of impact melt and physical state of rocks forming the peak rings. Numerous press releases, reports and (live) interviews on TV and Radio took up the results of our project.
Projektbezogene Publikationen (Auswahl)
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2018. Extraordinary rocks from the peak ring of the Chicxulub impact crater: P-wave velocity, density, and porosity measurements from IODP/ICDP Expedition 364. Earth Planetary Science Letters 495, 1-11
Christeson, G.L., Gulick, S.P.S., Morgan, J.V., Gebhardt, C., Kring, D.A., LeBer, E., Lofi, J., Nixon, C., Poelchau, M., Rae, A.S.P., Rebolledo-Vieyra, M., Riller, U., Schmitt, D.R., Wittmann, A., Bralower, T.J., Chenot, E., Claeys, P., Cockell, C.S., Coolen, M.J.L., Ferrière, L., Green, S., Goto, K., Jones, H., Lowery, C.M., Mellett, C., Ocampo- Torres, R., Perez-Cruz, L., Pickersgill, A.E., Rasmussen, C., Sato, H., Smit, J., Tikoo, S.M., Tomioka, N., Urrutia- Fucugauchi, J., Whalen, M.T., Xiao, L., & Yamaguchi, K.E.
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2018. Rapid recovery of life at ground zero of the end-Cretaceous mass extinction. Nature 558, 288-291
Lowery, C.M., Bralower, T.J., Owens, J.D., Rodríguez-Tovar, F.J., Jones, H., Smit, J., Whalen, M.T., Claeys, P., Farley, K., Gulick, S.P.S., Morgan, J.V., Green, S., Chenot, E., Christeson, G.L., Cockell, C.S., Coolen, M.J.L., Ferrière, L., Gebhardt, C., Goto, K., Kring, D.A., Lofi, J., Ocampo-Torres, R., Perez-Cruz, L., Pickersgill, A.E., Poelchau, M.H., Rae, A.S.P., Rasmussen, C., Rebolledo-Vieyra, M., Riller, U., Sato, H., Tikoo, S.M., Tomioka, N., Urrutia-Fucugauchi, J., Vellekoop, J., Wittmann, A., Xiao, L., Yamaguchi, K.I., Zylberman, W.
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2018. Rock fluidization during peak-ring formation of large impact structures. Nature 562, 511–518
Riller, U., Poelchau, M.H., Rae, A.S.P., Schulte, F.M., Collins, G.S., Melosh, H.J., Grieve, R.A.F., Morgan, J.V., Gulick, S.P.S., Lofi, J., Diaw, A., McCall, N. Kring, D.A., and IODP-ICDP Expedition 364 Science Party
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2019. Impactinduced Porosity and Micro-fracturing at the Chicxulub Impact Structure. Journal of Geophysical Research: Planets 124, 1960-1978
Rae, A.S.P., Collins, G.S., Morgan, J.V., Salge, T., Christeson, G.L., Leung, J., Lofi, J., Gulick, S.P.S, Poelchau, M., Riller, U., Gebhardt, C., Grieve, R.A.F., Osinski, G.R., IODP-ICDP Expedition 364 Scientists
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2019. Stress-Strain Evolution during Peak-Ring Formation: A Case Study of the Chicxulub Impact Structure. Journal of Geophysical Research: Planets 124, 396-417
Rae, A.S.P., Collins, G.S., Poelchau, M., Riller, U., Davison, T.M., Grieve, R.A.F., Osinski, G.R., Morgan, J.V., IODP-ICDP Expedition 364 Scientists
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2019. The First Day of the Cenozoic. Proceedings of the National Academy of Sciences of the United States of America 116 (39) 19342-19351
Gulick, S. P.S., Bralower, T., Ormö, J., Hall, B., Grice, K., Schaefer, B., Lyons, S., Freeman, K. H., Morgan, J., Artemieva, N., Kaskes, P., de Graaf, S., Whalen, M., Collins, G., Tikoo, S. M., Verhagen, C., Christeson, G. L., Claeys, P., Coolen, M., Goderis, S., Goto, K., Grieve, R., McCall, N., Osinski, G., Rae, A., Riller, U., Smit, J., Vajda, V., Wittmann, A., and Expedition 364 Scientists
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2020. Explosive interaction of impact melt and seawater following the Chicxulub impact event. Geology 48, 108-112
Osinski, G.R, Grieve, R.A.F., Hill, P.J.A., Simpson, S.L., Cockell, C., Christeson, G.L., Ebert, M., Gulick, S., Melosh, H.J., Riller, U., Tikoo, S.M., Wittmann, A.
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2020. Probing the hydrothermal system of the Chicxulub Crater. Science Advances 6, eaaz3053
Kring, D.A., Tikoo, S.M., Schmieder, M., Riller, U., Rebolledo-Vieyra, M., Simpson, S.L., Osinski, G.R., Gattacceca, J., Wittmann, A., Verhagen, C.M., Cockell, C.S., Coolen, M.J.L., Longstaffe, F.J., Gulick, S.P.S., Morgan, J.V., Bralower, T.J., Chenot, E., Christeson, G.L, Claeys, P., Ferrière, L., Gebhardt, C., Goto, K., Green, S.L., Jones, H., Lofi, J., Lowery, C.M., Ocampo-Torres, R., Perez-Cruz, L., Pickersgill, A.E., Poelchau, M.H., Rae, A.S.P., Rasmussen, C., Sato, H., Smit, J., Tomioka, N., Urrutia-Fucugauchi, J., Whalen, M.T., Xiao, L., Yamaguchi, K.E.
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2021. Ocean resurge-induced impact melt dynamics on the peak-ring of the Chicxulub impact structure, Mexico. International Journal of Earth Sciences
Schulte, F.M., Wittmann, A., Jung, S., Morgan, J.V., Gulick, S.P.S., Kring, D.A., Grieve, R.A.F., Osinski, G.R., Riller, U. and IODP-ICDP Expedition 364 Science Party
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2021. Shock-deformed zircon from the Chicxulub impact crater and implications for cratering process. Geology 49
Zhao, J., Xiao, L., Xiao, Z., Morgan, J.V., Osinski, G.R., Neal, C.R., Gulick, S.P.S., Riller, U., Claeys, P., Zhao, S., Prieur, N.C., Nemchin, A., Yu, S. and IODP 364 Science Party
