Porcupine Cave: A Window to the Ice Age

By Reilly Blakeslee
Lake George Gem and Mineral Club, Earth Science Scholar Program

Porcupine Cave, located in Park County, Colorado is an important part of the paleontological world. It is a wild cave and not easily explored. (Figure 1). It contains several types of ice age animals, as well as clues to the Pleistocene Epoch. Another uncommon feature of the cave is its mud stalagmite.    

Figure 1. Entrance into Porcupine Cave. Photo © by S. W. Veatch.

Several of the worlds' oldest ice age animal bones/fossils have been found there. The oldest mountain goat, coyote, and black footed ferret bones have been identified. There have been several cheetah teeth discovered. Ice age camel, ground sloth, wolves, deer, badgers, skunks, prairie dogs, lizards, snakes, turtles, frogs, and salamanders have all been found. These fossil animals provide insights about what the climate and ecosystem were like when all of these creatures were alive (Table 1, Figure 2).

Table 1. Types of Fossil Taxa found in Porcupine Cave

Badgers

Bear

Black-footed ferret

Bobcat

Cheetah

Coyote

Ermine

Fish

Foxes

Mink

Raptors

Weasel

Wolverine

Wolves

Figure 2. Ice Age animal bones are everywhere.
The bones can be simply scooped up by hand
from the cave sediments that have
been lost to time. Photo © by S. W. Veatch.

It is possible that some of the animals were killed by predators, and then drug to the cave. It is also possible that some of the animals were trapped there by snowstorms, or predators. Some animals could have chosen to die in a place that was out of the snow.

A unique type of stalagmite was found at Porcupine Cave (Figure 3).  The stalagmite is made of mud from melting glaciers.  Mud stalagmites are formed the same way as regular stalagmites, but with one small difference.  Instead of water with a mineral component forming the stalagmite, it is mud with a mineral component.  Add dirt, water, and calcium carbonate, and you have a mud stalagmite. However, there are still more steps that must occur before the stalagmite can form.  The drips of mud must come at a regular interval.  If not, the stalagmite will be irregular.  The mud hardens, forming layers of mud, which eventually become big enough to be considered a stalagmite.

Figure 3. Mud stalagmite found in one of the several
chambers of Porcupine Cave. Photo © by S. W. Veatch.

Mud stalagmites can also be formed by erosion. Water dripping onto a mud covered slope can drill holes. These holes usually have sharp pointed edges around them. Most mud stalagmites have very sharp peaks. The same process can happen with clay or sand. The larger versions found in the Colorado Plateau are sometimes called hoodoos.

Porcupine Cave is full of biodiversity and includes many animals that lived during the Earth’s last ice age. It has a surplus of rare features. From animal fossils to cave formations, Porcupine Cave has something to interest everyone.


References Cited:
Anthony D. Barnosky, 2004. Biodiversity response to climate change in the middle Pleistocene-The porcupine cave fauna from Colorado. Beverly and Los Angeles, California: University of California Press, Ltd. Retrieved from http://books.google.com/books?id=F9rs7k52goQC&printsec=frontcover&dq=porcupine+cave+colorado&hl=en&sa=X&ei=PdyfUMOjEMS0rQGp5oH4DA&ved=0CDAQ6wEwAA#v=onepage&q=porcupine%20cave%20colorado&f=false

Jim, E. , 2001, August 14. Colorado Cave Yields Trove of Ice Age Mammal Fossils. Retrieved from http://www.google.com/search?dq=Mud+stalagmites&hl=en&q=Mud%20stalagmites&sa=N&tab=pw

About the author:

Reilly Blakeslee is a twelve-year old, seventh grade student from central Colorado. She enjoys soccer, basketball, reading, and learning; especially about science and math. She participates in 4-H with her horse, sheep, pigs, and turkeys. This is Reilly's first published article. Reilly is a member of the Pikes Peak Pebble Pups Earth Science Scholars Program through the Lake George Gem and Mineral Club where she participates online. http://pebblepups.blogspot.com/