Mammoth Change

Geoheritage Highlight!

The heritage of our planet and the life that lives here, including us, has been driven over the ages by climate change. The Earth’s environment has changed during geologic time and it continues to change at an unusually rapid rate today. Human activities can have an impact on how climate changes. The heritage that we leave for the Earth’s future will be strongly influenced by what we do today.

 

A peaceful field hiding a wealth of history!

NPS

 

Extent of alpine glaciers once present on Pikes Peak based upon the glacial landforms left behind. (1:100,000 30 x 60 Minute Quadrangle of Pikes Peak, 1983)

NPS/GIP: Mariah Slovacek

 

A photomanipulation of the Florissant valley in winter showing what it might have looked like in the Pleistocene.

NPS/GIP: Mariah Slovacek

Mammoths in Florissant?

The warm greenhouse world of the Eocene abruptly transitioned to an icehouse world at the Eocene-Oligocene boundary, as permanent ice began to develop on a previously ice-free Antarctica. In less than a million years, the giant redwoods and many hardwoods of the Florissant Formation became uncommon in the landscape. Rather, cold-hardy spruces, firs, and pines came to dominate the Oligocene Antero formation of South Park, 30 miles to the west of here. Global temperatures continued to cool into the Pleistocene Ice Age. Glaciers developed on Pikes Peak, though not in the Florissant valley. However, it was still cold enough that animals like Columbian mammoth once lived here.

 

Fossilized mammoth jaw and tooth fragment.

NPS

These mammoth tooth and jaw fragments were discovered in 1994. The very subtle ridges on the top of the tooth are evidence that mammoths were grazers, feeding on grasses, sedges, and herbs. Columbian mammoths grew as tall as 13 feet (4 m) at the shoulders and likely weighed up to 10 tons.

 

References

Images used in construction of Pleistocene image:

Trees and mammoth images used under license from Shuttershock.com
Smilodon fatalis: Dantheman9758 at English Wikipedia
Przewalski's Horse: Becker1999 from Grove City, OH
African Harrier: Charles J. Sharp, Sharp Photography

 

How Old Was this Mammoth?

Radiocarbon dating is a way scientists can determine the age of more recent fossils. Using carbon, the building block of organic tissues, scientists can determine an approximent age of fossils as long as they are not more than 50 thousand years old. This is because, over time, the parent element, carbon-14 decays into the daughter element, nitrogen-14. This happens at a predictable rate, with half of the original carbon-14 into nitrogen-14 every 5,700 years. However, by about 50 thousand years, the amount of carbon is so small that it is at unmeasureable levels and thus nothing older can be dated this way.

The Florissant mammoth was dated this way and has been estimated to be around 49,930 years old!

 

Illustration showing carbon half-life progression over time. The top half shows carbon atoms (on the left) decaying to nitrogen atoms (on the right). The bottom timescale shows 100% carbon-14 successively reducing by half at each interval.

NPS/GIP: Mariah Slovacek