Poop Creek (Turtlesaur Coprolite?) EarthCache

A friend of mine introduced me to the famous Salmon Creek coprolites a few years ago when I came home from Iraq. At the time I did not know what a coprolite was. At first glance it looked like dog poop. I asked what it was and he told me it was fossilzed turtle dung. I was fasinated and wanted to find some for myself.

A few days later we loaded up the SUV and off we went in search of some coprolites. The desitination was Salmon Creek, not far from Toledo, WA. Once at the site it was not long before I found my first piece of turtle coprolite. I was hooked! At the end of the day I had my bucket full of coprolite and very proud of my little treasures.

I was told my coprolites are from prehistoric turtles called Turtlesaurs. Turtlesaur Coprolites are unique fossilized dinosaur droppings and most likely from a turtle-like dinosaur that lived in the wetlands of western Washington state between 12 and 20 million years ago. The dung droppings are preserved by the mineral Siderite, a carbonate of iron. Scatologists can tell a lot about the diet of the dinosaur from studying these coprolites. Remains of nuts, seeds and bone may be seen in the mineralized dung.

Coprolite, meaning "dung stone" , kopros means dung and lithikos means stone in Greek, is fossilized feces. And no, coprolite does not smell bad - it had undergone a fossilization process. Copro means "dung," from the Greek word kopros. The ending "-lite" is a common ending for fossil or mineral terms, coming from the Greek word lithos, which means stone. The term coprolite was coined around 1830.

Learning About Diets: Coprolites record the diet, feeding behavior, and habitat of prehistoric animals. Paleontologists can study the contents of a coprolite to see what one meal of an animal consisted of. For example, if the coprolite consists of partially digested plant material (leaves, seeds, bark, roots), the animal in question was probably an herbivore; if the coprolite contains bits of animal material (crushed bits of bones, sinew, claws), the animal in question was a carnivore.

The recognition of coprolites is aided by their structural patterns, such as spiral or annular markings, by their content, such as undigested food fragments and by associated fossil remains. The smallest coprolites are often difficult to distinguish from inorganic pellets or from eggs. Most coprolites are composed chiefly of calcium phosphate, along with minor quantities of organic matter. By analyzing coprolites, it is possible to infer the diet of the animal which produced them.

Coprolites have been recorded in deposits ranging in age from the Cambrian period to recent times and are found worldwide. However, animal excrement is easily fragmented and destroyed, so usually has little chance of becoming fossilized.

Now the debate. Is what I found really coprolite? A few geologists dissagree that the coprolites in Salmon Creek are turtle poop but instead are from decomposing trees. The geologists call these fossils pseudocoprolites.

Pseudocoprolites are excrement-shaped masses of siderite and limonite from clay-rich sedimentary rocks that range in age from Late Permian to Holocene. These objects have been widely accepted as being coprolites, but the ferruginous composition, absence of internal inclusions, and scarcity of associated vertebrate remains suggest that they may instead be pseudofossils created by mechanical deformation of plastic sediment. Possible abiotic mechanisms include coseismic liquefaction, intrusion of sediment into hollow logs, or expulsion of sediment in response to gravity. Alternatively, carbon stable isotope ratios indicate that sediment extrusion may have been related to emission of biogenic methane during early stages of diagenesis.

According to geologists, the Salmon Creek pseudocoprolites have never been found to contain any trace of organic material. They also exist in a wide variety of sizes and shapes which make it impossible to attribute them to any single type of organism. Furthermore, they are found highly concentrated in sediments that have never yielded animal fossils that could serve to corroborate their identity as dung. Overall there is a lack of evidence to support the notion that they are fossilized animal droppings. But if they are not true feces, then what exactly are they?

To begin with, their rust color indicates the presence of iron. Their chemical composition is, in fact, solid iron carbonate—the mineral known as siderite. How these mineral concentrations came to have their distinctive shapes has been the topic of much speculation, and at the moment there is no consensus. There are four hypotheses, each with their supporters and detractors. Two involve forces such as seismic liquefaction and gravitational pressure. A third envisions a mechanism involving hollow logs with holes through which the siderite could be forced.

The fourth hypothesis requires a scenario in which siderite mud is situated in strata above a layer of decaying plant matter undergoing methanogenesis—the production of swamp gas. In this hypothesis, gas pockets would develop within deposits of decomposing plant material underlying siderite mud which was itself beneath a plastic layer of sediment. When the pressure build-up of the gas reached a critical point, the strata had to “relieve itself” by forcing a stream of gas up through the siderite mud and the overlying sediment. It would be like the scene in the movie The Labyrinth, in which the heroes must cross through the Bog of Eternal Stench, the steamy swamp filled with black mud constantly bubbling and erupting with the sounds and smells of flatulence.

The apertures through which the siderite mud would extrude itself dilated as the pressurized materials squeezed through. As the pressure decreased, the diameter of the aperture reduced in size and created the distinctive pointed tips found on the pseudocoprolites, while irregularities along the edges of the aperture created the striations that can be found along the length of the specimens.

To the left of the GPS is a piece of Coprolite I found at the EC site. Coprolite comes in a varity of shapes and sizes.

Personally, I believe these are real coprolites, however I am not a scientist or a geoligist, but I do know what poop looks like and this looks like the real thing. Like my grandpa always said, "if it looks like poop and smells like poop, its probably poop..."

As I type this I'm looking at a coprolite I found in the creek and chuckling to myself because it looks like a pile of dog waste my dog left in my back yard.

When you visit this site, you be the judge. It looks real and I hope someday the geologists can agree on one thing and that is wether or not its real turtle poo.

Now here is the hard part, (no pun intended). The coprolite near the bridge looks like the surrounding rocks on the bank. Look at the attached pictures and take your time. The coprolites are all over the banks. You may even find some very colorful agates while here.

To get credit for this EC, post a photo of you anywhere near the EC site in Salmon Creek and the bridge in the background (no photos of just a hand) and please answer the following questions. Also post some pictures of the coprolites you find.

1. What is the average size of coprolites you find?

2. Do the coprolites feel heavy or lite?

3. Do you think the fossils are really coprolites or pseudocoprolites?

Cav Scout has earned GSA's highest level

PLEASE DO NOT POST YOUR ANSWERS IN THE LOG. ANY LOGS THAT SHOW THE ANSWERS WILL BE DELETED.

Why do I ask for a face in the picture of the EarthCacher finding any of my EarthCaches? A face shot is the same as a signature in a log book. Many geocachers feel in order to get a find you must sign the log book, period. EarthCaching is special and a human face is the same as a signature in a log book. I do not accept hand shots (pictures of a hand with GPS) because it does not show who’s really visiting the ECs I set up for all to enjoy. Besides, there is no log book for you to sign at a EarthCache.

For anyone who doesn’t want to post a picture of their face, then log the find as a note or don’t do it at all. Nobody is forcing anyone to come and visit any of my EarthCaches. I could argue that signing a log at a traditional cache is violating my personal rights because I have to sign a piece of paper. Maybe someone will forge my signature and steal my identity!

An argument that a photo violates a persons identity is foolish. Geocaching is a social activity. Eventually someone will meet you and know you are geocaching. If you want to live a secretive life then geocaching is not the place to do so. Cache on!

Do not log this EC unless you have answered the questions and have a picture ready to post! Logs with no photo of the actual cacher logging the find or failure to answer questions or negative comments will result in a log deletion without notice. Exceptions will be considered if you contact me first (I realize sometimes we forget our cameras or the batteries die). You must post a photo at the time of logging your find. If your picture is not ready then wait until you have a photo.

Sources of information for the EarthCache quoted from the Cumberland National Historic Park. I have used sources available to me by using google search to get information for this earth cache. I am by no means a geologist.. I use books, internet, and ask questions about geology just like 99.9 percent of the geocachers who create these great Earth Caches. I enjoy Earth Caches and want people to get out and see what I see every time I go and explore this great place we live in.