The Day the Earth Almost Died

credit: New York Times

A unique, and potentially landmark paleontological discovery was announced to the public last week.  The field of paleontology is marked with a great deal of secrecy, matched only by its history of false discoveries and unsupportable claims.  After a more than four years secretly excavating a site in the Hell Creek formation near Bowman, North Dakota, Robert De Palma, a PhD candidate at the University of Kansas, and several top scientists including Walter Alvarez at the University of California, Berkeley, revealed startling results.  Fellow scientists were told in a jointly authored article that the site Palma named Tanis, after an ancient Egyptian city where a Rosetta-type stone was discovered, is potentially a fossil record of the exact day the Earth almost died sixty-six million years ago.

That day was the day beyond all other days in the Earth's history, a day of destruction and death biblical in scope.  A day that could be poetically described as a day when God created a new Earth inhabited by new creatures--mammals. {Is 65,22; 66,22} It was the day the Chicxulub asteroid, a space rock whose diameter was half the length of Manhattan island, smashed into the coastline of the Yucatan, setting off a chain reaction so catastrophic that it killed the dinosaurs, then the apex species of the planet, and 70% of all life in existence. The gigantic explosion rained fire down on a region 1500 miles from the impact, turning the atmosphere hot enough to cause forest fires to erupt in India; created huge earthquakes and tsunamis with waves of 100 feet that altered coastlines, and ejected enough soot and sulfur into the stratosphere to cool the entire planet by 18 degrees.  Acid rain cause by the event may have been strong enough to kill vegetation that survived the blast and incineration, and poisoned the soil.  Covered in an apocalyptic gloom of dust and ash, photosynthesis stopped.  Such planetary waste is etched permanently in the geological record, known at the KT layer, a black band of carbon and a rare mineral found in meteorites, iridium.  This strata, about the thickness of a notebook, is found all over the world.

enhanced NASA photo faintly showing crater rim upper left

That such a single impact could cause the alteration of all life on this planet was not a hypothesis easily accepted by the scientific community.  In 1980 geologist Walter Alvarez and his father Luis Alvarez a nuclear physicist, proposed that the iridium bearing KT layer represented the debris of a planetary collision. The hypothesis was greeted with skepticism by paleontologists until the vast Chicxulub crater was discovered by a geophysicist looking for oil [photo] in 1991.  It has a scale sufficient to support the asteroid theory. Still, many experts thought dinosaurs were on the road to extinction before the impact took place due to other factors like climate change caused by massive terrestrial volcanic activity. This argument was supported by the geologic record too, because no dinosaur fossils have ever been found in strata up to three meters below the KT boundary, representing thousands of years of prehistory.  Not until 2010 did scientists reach a consensus agreeing that an asteroid impact triggered a mass extinction event that ended the earthly reign of the dinosaurs. Now, there may be fossil evidence from the Tanis site proving the Earth shattering catastrophe did just that.

The Hell Creek formation is famous in the annals of paleontology. The region was a verdant, low-lying basin dotted by streams, rivers and lakes during the Cretaceous--excellent dinosaur habitat.  Many groundbreaking discoveries have been made there including the first T. Rex unearthed in 1902 by Barnum Brown of the American Museum of Natural History.  It spans the KT boundary between the Cretaceous and Tertiary, now know as the Paleogene, eras. The Tanis site is unique not only because of its formation, but because of what its thin layers of sedimentary mud and sand contain. It appears to be have been created in a massive flooding with course material settling to the bottom and finer material on top. The sediments are strewn with tektites, a type of glass globule formed by the intense heat of a meteor or asteroid strike. Chicxulub tektites are rare. A known deposit occurs at a road cut outcropping in Haiti. De Palma went there and collected samples; he submitted these and the Tanis samples to a Canadian geophysical lab for comparison. The analysis shows an almost exact geochemical match. Entombed by the flood and quickly fossilized in the muck are a myriad of dead and dying creatures, both marine and freshwater; plants, seeds, tree trunks, roots, cones, pine needles, flowers, and pollen; shells, bones, teeth, dinosaur feathers, eggs and mammal burrows; tektites, shocked minerals, tiny diamonds, iridium-laden dust, ash, charcoal, and amber-smeared wood--recorded evidence of a catastrophic impact 66 million years ago.

De Palma at site, New Yorker

DePalma described to a New Yorker journalist visiting the site, “When I saw that, I knew this wasn’t just any flood deposit. We weren’t just near the KT boundary—this whole site is the KT boundary! He added, “We have the whole KT event preserved in these sediments. With this deposit, we can chart what happened the day the Cretaceous died.”  If he is correct, there is no other known fossil site like it anywhere, and his discovery is of momentous scientific value.  Walter Alvarez, a co-author of the Tanis report wrote, "It is truly a magnificent site...surely one of the best sites ever found for telling just what happened on the day of the impact.” De Palma found one very rare fossil in the prolific jumble of fossils that will take years to study and catalogue, and it is perhaps the most important find of all. At the bottom of the dig he discovered an intact dinosaur egg containing an embryo.  Convincing evidence that dinosaurs were living and reproducing, not on their way to extinction, on the day the Earth almost died.