A Golden Spike in Oklahoma marks a geologic boundary that has the attention of scientists across the world. The picture below shows what’s called the Katian Golden Spike. It’s been placed near Atoka (about 45 miles
southeast southwest of McAlester).
So what’s up with a big gold spike being hammered into the rocks? Well, long story short- it marks the beginning of a span of geologic time. This particular spike represents the start of the Upper Ordovician Katian Stage. The Ordovician Period is a span of time that lasted from about 485-million years ago to 443-million years ago. The Katian Stage was the second to last stage of the Ordovician. It lasted about 8-million years.
The spike marks a Global Boundary Stratotype Section and Point or GSSP. The location for a spike is determined by the first appearance of a particular species in the geologic record. In the case of the Katian Golden Spike, it marks the first place where Diplacanthograptus caudatus was found…a small aquatic animal that just floated around.
Kyle Hartshorn is with Dry Dredgers, “the oldest continuously-operating fossil club in North America”. He was also part of a group that recently toured Oklahoma’s geology and placed the spike in Atoka. He says these kinds of fossils look like little zippers or feathers, “These floating colonial animals were widely distributed by ocean currents, making them excellent tools for stratigraphic correlation. Other wide-ranging planktonic fossils are also found at the site, including conodonts (teeth-like structures from tiny lamprey-like primitive fish) and chitinozoans (little sac-shaped fossils of unknown origin).”
The placement of a Golden Spike is mostly ceremonial, according to Hartshorn, but it does help scientists who do research there in the future. There are Golden Spikes placed around the world but only six , including the Katian Spike in Atoka, are in the United States.