Please note: There is a fee to enter the Fort Stevenson State Park. If you do not have your North Dakota State Park Annual Pass, you can get a daily vehicle entrance pass for $7 at the booth entering the park, or in the visitor center.
There are two spots where the Earthcahe can be obtained! To obtain the needed information you must visit one of these stages.
The first location is very flat, easy terrain, and is handicap accessible as there is a sidewalk almost to it and where you would veer off it is very flat.
The second location is where you park at the designated puppy park, walk to the lake, and enjoy a beautiful walk along the rocky shore until you get to the posted coordinates. This terrain is more difficult.
Imagine it is 65 million years ago, during the Cretaceous Period in North Dakota. It is a subtropical warm temperature. Think of south Florida temperatures. You would find yourself surrounded by shallow epicontiental seas. These saltwater seas were never very deep, and a few hundred feet at most. These seas occupied what was the Western Interior Seaway. Which was essentially the North American continent. The greatest stretch of the Western Interior Seaway connected The Artic Ocean to the Gulf of Mexico!
Map is from Cretaceousatlas.org
Though not deep these seas were teeming with life animal and plant life! Marine reptiles, mosasaur, plesiosaurs, sea turtles, fish, sharks, clams, cephalopods and corals! Dinosaurs coming up needing to drink! From the North Dakota Department of Mineral Resources to help you picture this even better: The short version is: Bismarck = dinosaur age, Pembina Gorge = sea monsters, Medora = swamp critters, Dickinson = early mammals.
Scientists categorize fossils into 3 common groups.
1. Impression Fossils: These fossils contain prints, or impressions from plants or animals from long ago. The plant or animal lands in the mud, silt or sand and makes an impression. Over time it dissapears, but the impression remains. The mud, sand, or silt hardens into rock and an impression fossil remains.
2. Trace Fossils: These types of fossils capture the activities of ancient animals. These animals leave their footprints or scat which makes an impression in the soft mud, silt or sand. Just like impression fossils the soil hardens to form rock, preserving trace of the animal.
3. Replacement Fossils: These fossils are replicas of things that were once alive, such as trees, or sea creatures. These living things are trapped, die, and are covered by mineral rich water. As they rot, the organic parts are replaced by a hard mineral called silica. The minerals fill in the spaces and create a replacement, or replica fossil of the living thing.
Information taken from elementalscience.com
Petrified wood is the name given to a fossilized wood. Is is the fossilized remains of vegetation. The result of a tree having been replaced by silica, calcite, pyrite and/or another inorganic material. The material is buried by sediment and protected from decay as it is preserved. Often petrified wood exhibits details of bark, wood, and cellular structures. The organic wood is changed into stone, but only the shape and structural elements of the wood are preserved. Petrified wood rates a 6.5-7 on the Mohs Hardness Scale.
Mohs Hardness Scale is sourced from the nps.gov website
The state fossil of North Dakota is the 60 million year old Teredo-bored petrified wood. Teredo-bored petrified wood got is name because of little clams called "teredos" that drilled tiny holes into the wood before fossilized. Most of the Toredo-bored petrified wood is found in the Paleocene Cannonball Formation.
Photo is from ndstudies.gov
There is a petrified forest in the Theodore Roosevelt National Park's South Unit and it is considered to be the 3rd highest concentration of petrified wood in the country.
Depending on where you are in the world the colors of petrified wood vary. The colors of the petrified wood are caused by different compounds, or elements within the minerals. Red, brown and yellow can be caused by iron oxides. Pinks and oranges can be caused by manganese. Purple and blue is caused by manganese ioxide. Shade of green is caused by iron, copper, colbalt, or chromium.
Some common states that have petrified wood include: Washington, Oregon, Texas, Louisiana, Mississippi, North Dakota, California, and Colorado.
Common countries that have petrified wood include: USA, United Kingdom, Australia, Madagascar, Brazil, China, Egypt, India, and Indonesia.
Please Note: Collecting pieces of petrified wood on public land is illegal! People with large pieces on their land have acquired it from private property with permission of the land owner.
To Log this Earthcache:
Go to either of the posted locations and locate the petrified wood. Message me your answers to the following questions.
1. Do you think this fossil is an Impression, Trace, or Replacement fossil?
2. Per the Mohs Hardness Scale, what is petrified wood's hardness comparable to?
3. Examine the petrified wood. Do you feel this is a Teledo-bored infested piece of petfried wood? Why or why not?
4. Inspect the colors of the petrified wood. What elements or minerals do you feel it contains?
5. What are the approximate dimensions of the largest piece in front of you?
6. Please provide a photo of you, your geogroup, or a personal item to prove you visited The Land Before Time Earthcache.
Thank you for coming to my Earthcache!