Geochemistry

The Haitian glassy spherules are of two kinds: more abundant ones made of black glass, and rarer ones made of yellow glass. The chemical composition of the glasses indicates that they could have been derived from continental rocks of granitic composition, plus a minor component of limestone and clay.28 This is consistent with an impact onto a continental shelf, where limestones, muds, and sulfur-bearing rocks are apt to be found, and which was the setting of the Chicxulub region during late Cretaceous time.

Imagine again the impact of a meteorite 10 km in diameter, but now focus on the target rocks and what happens to them. The temperature at ground zero instantly far exceeds the point at which limestone and sulfur-bearing rocks are converted into gases. These gases, along with vaporized meteorite and other target rocks, are lofted high into the atmosphere and distributed around the entire earth. Estimates are that billions of tons of both carbon dioxide and sulfur were injected into the atmosphere.

Not only did the chemical signatures of the Haitian glasses match those of the rocks from Chicxulub, so did the isotopes of oxygen, neodymium, and strontium. The isotopic measurements were made by Joel Blum and Page Chamberlain of Dartmouth, the university of Officer and Drake, showing that the geology department there was not monolithic in its view of the Alvarez theory.29 Blum and Chamberlain found the Chicxulub igneous rock and the Haitian tektites to have identical isotopic ratios. The odds of this happening by chance are vanishingly small, and therefore not only are the two of the same age, as previously confirmed, they are linked by origin. However it was that the Chicxulub melt rock and the Haitian tek-tites formed, they come from the same source.

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