The energy estimated to have been released by the Chicxulub collision is between 108 and 109 megatons, or equal to about twice all the world's present nuclear arsenal. All these pieces of the puzzle are helping us understand and reconstruct an image of the end of the Cretaceous on Albion Island 65 million years ago, both before and after the impact. Impact events such as this one leave a complex array of deposits. During the expedition, we collected samples of carbonate from the ejecta that could give insight into our model predictions of target rock vaporization at Chicxulub. The relative amounts of heavy and light isotopes of carbon and oxygen in these carbonates are analyzed to determine if fractionation due to vaporization has occurred.
Isotopes fractionate when they change states, such as going from a solid to a gas.
For Chicxulub, when the target material was vaporized by the heat of the impact, the carbon dioxide vapors released should have contained higher concentrations of the lighter carbon and oxygen isotopes, with the heavier isotopes remaining behind in the solid ejecta. This signature may have been captured in the rocks at Albion Island if some of the gases produced by the impact condensed from the vapor plume. We did collect lots of samples and gained a greater respect for nature and the beauty of the lucky survivors of that dark episode 65 million years ago. Geologists use fossils as time markers in the geologic record. We left Belize with more questions than answers, as is often the case in the scientific process of discovery.