Sunday, July 28, 2013

Remarkable Trace Fossil Found Near Woodland Park May Hold Clues to an Ancient Sandstone

By Steven Wade Veatch and Zachary Sepulveda

Winding into the mountains, U.S. highway 24 closely follows the Ute Pass fault, a major fault that separates the Rampart Range from the Pikes Peak massif and the rest of the Front Range. Starting southeast of Cheyenne Mountain, the Ute Pass fault can be traced for about 60 miles, and heads north along state highway 67 beyond Woodland Park. The fault zone is relatively wide and filled with broken and fractured rocks that create the course of Fountain Creek in Ute Pass.
There are at least three resistant ridges made up of sandstone exposed along Ute Pass and in the Woodland Park area. These can be thought of as “fault slices” of a sandstone rock unit “jammed” in Pikes Peak Granite during past movements of the Ute Pass fault. The sandstone rocks are called “injectites” by a number of geologists to describe this remarkable formation. Generally, the color of the injectites is reddish or maroon, but some of the weathered injectites have a buff discoloration on weathered surfaces that is related to the iron oxide cement present in the sandstone.

Today the injectites remain a source of much scientific debate. This was thought to be a sandstone unit called the Sawatch Sandstone that was deposited during the Paleozoic Era in the Cambrian Period—when there was an explosion of multicellular life. Geologists give names to units of rock that were formed generally in the same way at the same time so they can talk about them and map them. Upon closer examination, it is clear this is probably not Sawatch Sandstone. During a recent field trip attended by  seven geologists studying these features in Woodland Park, the scientists began to consider this sandstone was perhaps pre-Cambrian, formed at a time before there was multicellular life on Earth. During the intense and concentrated discussion during this field trip, the scientists considered it a distinct possibility this sandstone was laid down before larger life forms were present; Steve Spence, a geology student at Pikes Peak Community College, climbed a steep slope of this enigmatic sandstone while the geologists were fervently debating.  He came back down with an object he had never seen before and brought it to one of the authors (Veatch) and said, “What is this unusual looking thing?”

Steve Spence, a Pikes Peak Community College Student
with the trace fossil he found. Photo © by S.W. Veatch
Veatch knew exactly what it was—it was a trace fossil of a larger, multicellular creature that once crawled its way through the wet and moist sand millions of years ago. This large trace fossil put the primordial sandstone back in the Paleozoic when there were large, multicellular organisms.


The tube-like structure or the trace fossil was formed by the creature crawling through this ancient
sand and can be clearly seen from this side view. Steven Spence specimen. Photo © S. W. Veatch.

Trace fossils, also known as ichnofossils, are a very important kind of fossil, they record behavior exhibited by prehistoric creatures. They are formed by animals performing actions, rather than animals dying and being preserved in sediment. For instance, a trace fossil might be formed by a worm burrowing its way through the sand, leaving a trail that gets preserved for all of eternity; or a dinosaur traveling to its nesting site and leaving a trail of footprints in deep mud. The term trace fossil may also include other things like remnants organisms left behind, for example, egg shells or coprolites (scat or droppings). Trace fossils leave us with indirect evidence of how past animals lived their lives and how they may have behaved.

Footprint fossils can give us insight not only into the behavior of prehistoric animals, but also into their physical attributes. By looking at footprints we can determine the size, speed, and weight of the animal creating the print. Trace fossils are a valuable source of information on prehistoric animals' behavior and biology.

This is a good example of how science works, and how something can change like the name and age of a sandstone unit. Geologists for decades thought it was the Sawatch Sandstone, and now geologists do not know what the name of the sandstone is or the age of it. Now science has a trace fossil from Woodland Park to add to the understanding of this puzzling sandstone. Scientists will soon probe the mysteries of this ancient sandstone embedded in Pikes Peak Granite and hopefully assign a name and age to it.

About the authors:

Steven Veatch is from a descendant from Cripple Creek miners who mined in the Cripple Creek and Victor Mining District from 1892 to the late 1930s. He teaches the Pikes Peak Pebble Pups to become responsible rock hounds, writers, poets, and scientists. 











Zachary Sepulveda attends Palmer Ridge High School in Monument, Colorado. He is from Southern California, and has always been interested in geology, paleontology and biology. He is looking forward to making a meaningful contribution to the field of science.  His other interests include creative writing and drawing. Some of his poetry and drawings have been published in magazines such as Deposits and in local newspapers. Zachary is a member of the Colorado Springs Mineralogical Society (CSMS) and participates actively in the Pebble Pup/Junior program. He is also a member of the Colorado Scientific Society. 

5 comments:

  1. Hello Professor Veatch! I have decided to check out your blog page for the very first time! For a while, I didn't even know that this existed! It's a pleasure getting to talk to you and the others on a blog! Did you see the article about the cave in Greece? It's called Agios Georgios. If you haven't seen it, you should probably read this article. This cave had been a den for hyenas in the time of the late Pleistocene! You can see the remains of hyenas, bones, plants and other object that are still in the cave! They have been coated with other minerals by now, but you can still see the remains withinn all of the minerals!

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    1. Hi Jenna, I will read this article this weekend for sure. Thanks for your help and your interest in the advancement of scientific knowledge.---Steve

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    2. You are out in Ute Pass, right?

      There is a Palaeozoic and a Mesozoic layer, but are they differentiated by different faunas on top of each other?

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  2. Sorry about my typos in my blog post!

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  3. This cave is famous for all of the remains that have now been fossilized in the stalactites and stalagmites. This cave has several spleleothems. This cave has had over 80,000 visitors so far. They control the number of visitors per visit to manage and maintain the cave's microclimate. Therefore, the speleothems, stalactites, and stalagmites are in excellent condition and have remained intact. This was a very interesting article, this is all that I can remember from this article. Enjoy!

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