Unless you’ve been hiding under a rock in Jurassic Park, you’ve heard that 66 million years ago the dinosaurs just disappeared. After roaming and ruling the planet for 165 million years – Poof! … well maybe it was Boom! … they were gone.
This famous extinction event is recorded in rocks and is called the K-T boundary* (Cretaceous-Tertiary), and if eliminating the dinosaurs wasn’t bad enough, this earth-altering cataclysm also eliminated 75% of ALL animal species on the planet.
And the cause of this near obliteration of life on earth is one of the biggest scientific mysteries of the ages. Over the years scientists, and even non-scientists like cartoonist Gary Larson, have suggested reasons for this mass extinction at the K-T Boundary.
But the two ideas that have gained the most traction are either a prolonged and prodigious series of volcanic eruptions in what is now India, or a Manhattan-size meteorite screaming through space and crashing into the Yucatan Peninsula in Mexico … or a combination of the two.
Scientists can get pretty huffy about pet theories and a healthy debate has continued for the past 40 years while researchers look for definitive proof. But imagine if you could actually see and touch tangible evidence of such an astounding event – walk right up and put your finger on proof that an astoundingly huge asteroid slammed into the earth and finished the dinosaurs.
Well, you can!
On our recent camping trip out west, Terri and I went looking for this mystical place in the extreme southeastern corner of Colorado, and we found it near the small town of Trinidad – the K-T Boundary
Trinidad is relatively unknown, and would qualify as being “in the middle of nowhere.” But it’s on the interstate and halfway between Santa Fe and Denver, so it’s a busy overnight stop for car travelers, most of whom wouldn’t know the K-T Boundary from a K-Cup coffee.
But enthusiastic rockhounds rub their rock hammers with glee when they dream of a trip to the nearby Trinidad Lake State Park: home of rock-solid proof that a meteor impact wiped out the dinosaurs.
The “asteroid theory,” which started all the excitement, originated in the early 1980s with geologist Walter Alvarez and his Nobel prize-winning physicist father Luis. On a field trip to Gubbio, Italy the duo found a thin claystone layer that had abnormally high levels of iridium, which is extremely rare on earth, but is abundant in meteorites.
After age-dating the rock layer, they proposed the theory that 66 million years ago a huge meteor impacted earth, creating a global cloud of dust and rock debris which blocked sunlight for months. Without sunlight, photosynthesis stopped, all vegetation died along with the plant eaters, resulting in wholesale death up and down the food chain. The proof in the fossil record is indisputable (so far anyway): dino bones below the iridium layer, and none above.
So this thin, iridium-rich rock is the holy grail for curious folks looking for answers to the question of dinosaur extinction. And if you want to see it for yourself, all it takes is a pleasant, quarter-mile hike along the Long’s Canyon Trail in Trinidad Lake State Park.
After a bit of a scramble up the hillside, you’ll be standing next to bona fide, world-famous geologic history.
This photo is the money shot of the rock outcrop, and immediately above my finger is the dark gray, iridium-rich claystone that’s so famous. And why is this thin, relatively insignificant looking rock relevant? Because 66 million years ago it was a dust cloud delivering death to most of the life on the planet, and there are few words more significant than “extinction.”
There have been 5 extinction events in earth’s history. And it’s scary to think that each time life on earth … and that’s all life … was nearly wiped out. Modern humans have been around for considerably less than one million years, but to put the K-T extinction in perspective, the dinosaurs dominated the planet for 165 million years. And the entire species was decimated in what geologists would call an instant.
I’m a self-admitted science nerd, and as a geologist, seeing and touching tangible proof of a global extinction event was not only humbling, awe-inspiring, and thought provoking, it also ticked a big box on my Bucket List. But even if you’re only mildly curious, you’ll never find a more important, easier-to-access scientific site than on this short hike in southern Colorado.
*Like most sciences, geology has esoteric nomenclature that sometimes seems specifically designed for confusion. For the record, the K in K-T stands for Cretaceous. It was named by the Belgian geologist who discovered it, using the German word for chalk which is kreide … hence the K. And to add to the haze, K-T has since been changed to K-Pg, which stands for Cretaceous-Paleogene. But, the boundary has been called K-T for decades so we decided to go with a name everyone recognizes … now even you.