K-T boundary clay is an iridium-rich, sooty deposit that can be found in locations all over the world.
The layer varies in thickness, but is always found at the geologic boundary between the end of the
Cretaceous, and the beginning of the Tertiary Period.
Since the end of the Cretaceous marks the
end of the dinosaurs (65 million years ago), AND iridium is an element found in greater abundance
in meteorites than on Earth, scientists believe the sooty K-T boundary material is a world-wide fallout
from a giant asteroid impact, and that it was this catastrophic event that caused the demise of the
dinosaurs. The impact is believed to have occurred in what is now Yucatan, Mexico, where scientists
have discovered a crater over 100 miles in diameter under the water of the Gulf. It is called Chicxulub.
This sample available is from the Rangeley area of Colorado, is 1/" W X 1 1/4" H X 7/8" D in size, and is presented in a 2.5-inch hinged perky. Contains carbonaceous shale, mudstone and claystone.