Protracted volcanism after large impacts: Evidence from the Sudbury impact basin

Teresa Ubide, Paul C. Guyett, Gavin G. Kenny, Edel M. O'Sullivan, Doreen E. Ames, Joseph A. Petrus, Nancy R Riggs, Balz S. Kamber

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Morphological studies of large impact structures on Mercury, Venus, Mars, and the Moon suggest that volcanism within impact craters may not be confined to the shock melting of target rocks. This possibility prompted reinvestigation of the 1.85 Ga subaqueous Sudbury impact structure, specifically its 1.5 km thick immediate basin fill (Onaping Formation). Historically, breccias of this formation were debated in the context of an endogenic versus an impact-fallback origin. New field, petrographic, and in situ geochemical data document an array of igneous features, including vitric shards, bombs, sheet-like intrusions, and peperites, preserved in exquisite textural detail. The geochemistry of vitric materials is affected by alteration, as expected for subaqueous magmatic products. Earlier studies proposed an overall andesitic chemistry for all magmatic products, sourced from the underlying impact melt sheet. The new data, however, suggest progressive involvement of an additional, more magnesian, and volatile-rich magma source with time. We propose a new working model in which only the lower part of the Onaping Formation was derived by explosive “melt-fuel-coolant interaction” when seawater flooded onto the impact melt sheet in the basin floor. By contrast, we suggest that the upper 1000 m were deposited during protracted submarine volcanism and sedimentary reworking. Magma was initially sourced from the impact melt sheet and up stratigraphy, from reservoirs at greater depth. It follows that volcanic deposits in large impact basins may be related to magmatism caused by the impact but not directly associated with the impact-generated melt sheet.

Original languageEnglish (US)
Pages (from-to)701-728
Number of pages28
JournalJournal of Geophysical Research: Planets
Volume122
Issue number4
DOIs
StatePublished - Apr 1 2017

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Keywords

  • Explosive volcanism
  • Impact basin
  • Subaqueous volcanism
  • Sudbury structure

ASJC Scopus subject areas

  • Geophysics
  • Oceanography
  • Forestry
  • Ecology
  • Aquatic Science
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Cite this

Ubide, T., Guyett, P. C., Kenny, G. G., O'Sullivan, E. M., Ames, D. E., Petrus, J. A., Riggs, N. R., & Kamber, B. S. (2017). Protracted volcanism after large impacts: Evidence from the Sudbury impact basin. Journal of Geophysical Research: Planets, 122(4), 701-728. https://doi.org/10.1002/2016JE005085