Currently, there is only one known Earth impact crater associated with dinosaur extinction: the Chicxulub crater in Mexico. In addition, tiny glass fragments from the impact ejecta (the rock and soil that sprayed from the crater when it formed) were found in 1990 in the Caribbean Ocean on the island of Haiti. The ejecta debris appears to fall in line with the Chicxulub crater. Another crater, the Manson structure in Iowa, was once thought to have formed at the end of the Cretaceous, but subsequent studies show it is not the correct age. Two impact crater sites in Belize and Mexico, about 290 miles (480 kilometers) and 140 miles (230 kilometers) from the Chicxulub crater, respectively are thought to be from the ejecta of Chicxulub—the material thrown up from the crater that landed nearby.