Found This Ghost Shrimp Colony On Our Saturday Trip To Big Brook

[njfossilhunter]

After Jim and Frank have left for the day yesterday I decided to stay a little longer and went into one of the tributaries and came across the shrimp colony along the wall of the bank ,,,just under the water line,,,while screening in the brook. I have to put it back together ,,I'm sure I lost some small pieces as I pulled it out of the stream. I never seen such intact burrows before. I never knew that they built so many burrows going in different directions.

Here is a picture of the pieces after taking them out of the bags when I got home....I have since matched six pieces of the burrow's together so far....They are out in the sun right now to dry so I can glue them together.

Tony

[Boesse]

I'm really looking forward to seeing some of these burrows being three dimensionally reconstructed! I find trace fossils really interesting, and typically traces such as this are only seen in cross section. This burrow system is identifiable as Ophiomorpha nodosa.

[njfossilhunter]

I'm really looking forward to seeing some of these burrows being three dimensionally reconstructed! I find trace fossils really interesting, and typically traces such as this are only seen in cross section. This burrow system is identifiable as Ophiomorpha nodosa.

Thank you .....Since starting this post I was able to match one of the burrows to the larger flate piece in the second picture. What do you mean by cross section ? You do usually find these internal mold's of these burrows whole with just one burrow or maybe two,,, three if your lucky in float in the stream bed.

Edited August 2, 2015 by njfossilhunter

[fossilized6s]

Neat. Can't wait to see it finished.

[Boesse]

Usually this is all you ever see in the field, and even this is a remarkable specimen.

[njfossilhunter]

Usually this is all you ever see in the field, and even this is a remarkable specimen.

Cool.....That is a remarkable looking specimen....Thank you for sharing this picture with me.That's what they look like here if your luck to find something like this,,but its not often you see this exposed,and if you do they get eroded so much that all the bumps get worn smooth because they are always exposed at the water level. I was lucky to stumble across mine because it was protected by a sand and gravel bar that formed along side the formation wall that ran into and under the stream protecting the burrows while the water action percolated and eroded the matrix leaving the borrows intact. What I'm not sure of is what part of the Monmouth Group its from,,,,I'm thinking it might be the lower Navesink contact layer with the Mount Laurel formation,,,but some say there is no Mount Laurel ,,but Wenonah is the contact layer with the Navesink in this area. I'm going to talk with David Parris at NJSM and get this input about the contact layer's that are in this part of Big Brook. I finished putting five of the burrows pieces together,,using paleo-bonds Jurassic glue,,I have two other pieces that fit together but don't seem to fit with the main section,,,it might be from another section that I didn't pull out of the water,,,I have to go back this week and look for more,,but this time I will be better prepared to exstact them,,,,since the water is only about seven inches or less I might bring some sandbags and try to divert the water around the area in question,,I will try to post some pictures tonight so you can see the process I've made so far.

Thanks again for sharing the picture.

Tony

[Jeffrey P]

_{Really nice and unusual find, Tony. Would love to see it reconstructed. Congratulations and good luck.}

[njfossilhunter]

_{Really nice and unusual find, Tony. Would love to see it reconstructed. Congratulations and good luck.}

Thanks Jeffrey....Hows the trip going...I'm hoping everything is well.

[frankh8147]

Nice job Tony! I can't wait to see you put that together!

[njfossilhunter]

Nice job Tony! I can't wait to see you put that together!

Thank you.... frank.

[njfossilhunter]

I really need to take pictures outside where the light is much better. This was taken on my kitchen table at night...Not very good...Well ... Here is a picture of what I have now...The lose piece doesn't really seem to match up to any of the other sections that I have ,,,but it might fit other sections that may still be in the formation.

[Darwin Ahoy]

Nice to see some good sections come out intact. Sometimes you'll find sections where the entire walls can be covered in those burrows, but they are not solidified and are unable to be recovered.

[njfossilhunter]

Nice to see some good sections come out intact. Sometimes you'll find sections where the entire walls can be covered in those burrows, but they are not solidified and are unable to be recovered.

They can be tough to remove from a wall. You would need to remove a large area and haul it back to a place where it can be prep ...and you know this type of formation would nearly make it impossible..... I was lucky to find them where I did. Mother nature did all the hard work for me....Gosh I love that lady...

Edited August 5, 2015 by njfossilhunter

[JimB88]

that looks good so far..should be an interesting piece at any rate!

[erose]

15 years ago I assembled and wrote, along with a few others, the Big Brook Field Guide that the NYPS provides for field trips. The stratigraphy was a real challenge. Different maps with different formations and different geologists with different interpretations as well. In the end what seemed to be the more likely scenario was that the Navesink Formation is sitting on top of the Wenonah as an unconformity with possibly a few lenses of Mt Laurel sand here and there. If you were upstream of Boundary Road you may have been seeing Wenonah in the banks. There are two common burrows: Ophiomorpha with the rounded pellets and Thallasinoides which have a smoother surface. From what I understand they may be from the same critter but different burrowing conditions. The round pellets were used by the shrimp where they needed to reinforce the burrow walls. Here in Texas we get another burrow called Spnogiomorpha(sp?) which looks very sponge-like and was even thought to be a sponge originally. In fact it is a burrow with linear striations formed when the critters scratched thru the matrix.

Your assembled specimens are pretty darn cool!

[njfossilhunter]

that looks good so far..should be an interesting piece at any rate!

Thank you ...Its getting there. Hopefully I will find more when I go back to the brook.

15 years ago I assembled and wrote, along with a few others, the Big Brook Field Guide that the NYPS provides for field trips. The stratigraphy was a real challenge. Different maps with different formations and different geologists with different interpretations as well. In the end what seemed to be the more likely scenario was that the Navesink Formation is sitting on top of the Wenonah as an unconformity with possibly a few lenses of Mt Laurel sand here and there. If you were upstream of Boundary Road you may have been seeing Wenonah in the banks. There are two common burrows: Ophiomorpha with the rounded pellets and Thallasinoides which have a smoother surface. From what I understand they may be from the same critter but different burrowing conditions. The round pellets were used by the shrimp where they needed to reinforce the burrow walls. Here in Texas we get another burrow called Spnogiomorpha(sp?) which looks very sponge-like and was even thought to be a sponge originally. In fact it is a burrow with linear striations formed when the critters scratched thru the matrix.

Your assembled specimens are pretty darn cool!

Thank you ..Erose. What do you mean by round pellets..? Did they use something to form and or reinforce the burrows and by any chance do you have a picture of these pellets. I was told some years back that the pellet looking areas was made by the shrimp using its claws to shape the burrows.

I really need to learn how to tell the formation apart...I have been collecting bags of samples from all over the brooks to help me learn about the formations...it would be a big help if I had someone with me that really knew the formations well.....The one I would love to have with me is Ralph Johnson...now there is a man that knows this stuff.

Tony

[erose]

Tony,

I believe the round pellets are maybe just mud or matrix mixed with something else. Think of a crayfish burrow where they build a chimney up from the ground from little balls of mud. In this case the shrimp was using something similar to reinforce the walls of the burrow in a softer matrix.

What you need to do is find written descriptions of the formations and then compare that to what you see on site. See if you can get a copy of this map and the associated text.

SUGARMAN, P. J. AND J. P. OWENS. 1996. Bedrock Geologic Map of the Freehold and Marlboro Quadrangles, Middlesex and MonmouthCounties, New Jersey. New Jersey

Geological Survey, GMS 96-12.

And yes, we would all like a full download of Ralph Johnson's brain.

Edited August 7, 2015 by erose

[njfossilhunter]

SUGARMAN, P. J. AND J. P. OWENS. 1996. Bedrock Geologic Map of the Freehold and Marlboro Quadrangles, Middlesex and MonmouthCounties, New Jersey. New Jersey

Geological Survey, GMS 96-12.

And yes, we would all like a full download of Ralph Johnson's brain.

Thank you..erose for the info. I agree,.A full download of Ralph's brain would be very helpful ..but I don't think I have that many GB's left in my brain...

Edited August 7, 2015 by njfossilhunter