Sink Your Teeth Into Nanjemoy WMA EarthCache

This is an Earthcache – as such, there is no physical cache. Instead you will visit the beach here at the Nanjemoy Wildlife Management Area and perform a geology lesson. Access to the Potomac requires a 1/4 mile hike down a dirt trail. This earthcache was placed with Permission of the Nanjemoy Wildlife Management Area. Visitors may sift the sands for fossils, but digging or disturbing sensitive areas is not permitted. The park is open sunrise to sunset, and hunting is permitted during posted seasons. If you plan to search for sharks' teeth, the WMA suggests that you go at low tide. You can find a LINK to the lower Potomac tide chart here.

Nothereeither, JPWAVE, and I were out on a Cache Across Maryland run here in Southern Maryland to find CAM 2022 - Nanjemoy WMA. After we made the hike down and found it, I suggested to them that we should go down to the beach to search for sharks teeth.

While making our way down to the water I figured this was an opportune time to tell a "dad joke." I asked them "Why do sharks swim in Salt Water?" This drew blank stares. With a big grin I replied "Because pepper water makes them sneeze!" Of course I laughed at my own joke, and to my surprise, both of them laughed too!

With everyone in a great mood from my silly joke, we arrived at the beach to find that there was already two groups combing the waters edge for teeth. One couple had waterproof boots and were ankle deep searching. I approached the them and asked if they had found any shark teeth. She said "yes" and kindly showed me a handful of the teeth they collected.

”Wow!” We couldn’t wait to get searching. Before we started, she and her husband gave us a little "shark tooth hunting" advice. They said we could use a screen or colander, but it is much easier to walk the shoreline and look down into the water. I was concerned about getting my boots wet, but they assured us that shark teeth can be found on the beach if it hasn’t been already combed over or just within the waters edge.

Within a few minutes (seriously, not even 5 minutes) I had found my first shark tooth. If you look at the photo below it is about two inches down from my green walking stick. I couldn’t believe how easy this was as I reached down into the water and grabbed my prize. A minute or two later Nothereeither exclaimed “I got one!” and then JPWAVE said "me too!"

I had a pull tab from a can I CITO’d along the trail and used to show a size comparison. As you can see, my tooth was pretty tiny even compared to it.

Now that I found one, I just had to know what kind of shark this tooth belonged to. Below I have added a chart of common sharks teeth that can normally found in Maryland. I matched it up to what appears to be a SAND TIGER SHARK TOOTH.

I also had a few other questions that I needed to find the answers too.

Why are there so many sharks teeth here in Nanjemoy Wildlife Management Area?
The answer is that over a million years ago, Charles County was covered by a shallow sea. These ancient shallow waters were perfect breeding and nursery areas for sharks.

Are shark teeth fossils?

Yes! The teeth you will find here are actually fossils, not teeth recently lost by today’s shark population. Sharks have multiple files (rows) of teeth. Sharks can shed many thousands of teeth throughout their lifetime, and they then replace them from these files.

How does a shark tooth fossilize?
Only teeth that rapidly become buried in sediments have a chance to become fossilized. The ones that don’t quickly decompose, making the odds that teeth become fossilized not good. The good news for fossil hunters like you is that sharks have roamed the seas for millions of years making the odds of you finding one very likely.

Why is my sharks tooth black?
The answer is that when Shark teeth get buried in sediments, they absorb surrounding minerals which turns them from a normal white tooth to a black, gray, or dark tan tooth.

That was a pretty fun adventure. Now it is your turn to come here and find a tooth!

LOGGING REQUIREMENTS:

To log this Earthcache: Read the geology lesson above. Answer all four questions posted below. Answers for 1-3 can be sent via e-mail or messenger contacts on my Geocaching profile. Only post the answer to question 3 in your logs.

QUESTION 1. Why are there so many sharks teeth to be found here at Purse State Park?

QUESTION 2. Why are these shark teeth fossils black?

Find a sharks tooth via scanning the ground or sifting through the sand (This is why this cache has a 4 difficulty). You may also ask other beach goers there if they have found a tooth, and perhaps borrow it so you can take a photo of it to meet the requirements for this earthcache.

QUESTION 3. In your log tell us how long it took to locate a tooth, how you found it, what size it is, and identify what type of shark it came from.

POST PHOTO. Posting a photo of your tooth find. This readily indicates that you (and anyone else logging the find) are at the location. You do not have to show your face, but the photo should have the shark tooth you found in it. PLEASE DO NOT CLAIM A FIND IF YOU DO NOT FIND A SHARK TOOTH.

NOTE: Per newly published Earthcache guidelines, this photo requirement is REQUIRED to claim the find.

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