Mid December trip to Central PA Ordovician

[Shamalama]

As fall has finished dropping leaves and caused Poison Ivy and most insects to go dormant, I have been exploring some prospects in the Paleozoic of Central Pennsylvania.  On one trip back to help my folks get a Christmas tree, I had time to spend and hour or so at an abandoned quarry that exposed Ordovician aged rock.  Unlike the exposures of Ordovician rock in the Cincinnati/Louisville region of the US, or southern Ontario, or the Minnesota/Iowa area, Central PA is not know for heaps of fossiliferous limestone or shale.  One has to do a little research to find what formations have fossils, and then try and find an exposure that you can prospect.

 

I found one such quarry from an old guidebook out in Cumberland County, PA. It has exposures of the Chambersburg formation which is known to have fossils and is also known to have a bed of rock that contains an unusual Echinoderm called "Nidulites". My goal was to verify if fossils were present at the site and then try to locate the "Nidulites" bed.

 

View of the quarry wall. The rock was tilted NE in one direction (away from the camera) and N in another direction (to the left of the photo).

 

I started at the south end of the quarry (right side of pic above) and started to look through the fallen scree and exposed rock layers. Not finding anything I moved north along the walls of the pit until I started to find some hints of fossils in the rocks. Mostly cross sections in massive limestone, but at least there were fossils there.

 

This is what it looked like along the walls and in the talus along their base.

 

There were multiple pieces of limestone with Calcite crystals, both massive and crystalline, in some areas as the veins filled in cracks within the rock ages ago . I found one piece that had a couple of small Fluorite cubes on it, a rare find in the field!

 

I finally started to find some fossils in the talus concentrated in one area but could not figure out the layer they came from. Preservation was ok but as they came from fractured massive rock, completeness was not the best.  Here are my finds:

 

Leptanea sp. Brachiopod

 

Sowerbyella sp. Brachiopod

 

Possibly part of an Isolteus sp. genal spine

 

Unknowns

 

So not too bad for a couple of hours of looking. I'll have to visit the quarry again in the future and see if I can find more in the talus and maybe trace the bed that the better fossils come from.  No "Nidulites" either, but I am not discouraged. I confirmed that fossils can be found here, I just need to do some more looking.

 

 

[grandpa]

8 minutes ago, Shamalama said:

As fall has finished dropping leaves and caused Poison Ivy and most insects to go dormant,

I have had an experience with "dormant" poison ivy that probably bears sharing. 

I was digging in a Central Texas creek bank for Eocene fossils.  In the summer, the bank had been covered with P.I. so I decided to come back in winter.  It was indeed winter when I returned, and no P.I. in site as all of the leaves were gone.  I was plowing thru a lot of roots in my excavation of the fossil lens I was working.  You have already guessed the outcome.  The roots were from the P.I. and gave me one of the worst reactions I've ever had to P.I.  The leaves may be gone, but the roots are anything BUT dormant. 

Be careful out there, nature can jump up and bite you even in the fall/winter. 

[nala]

Very nice report and finds!

[FossilDAWG]

Nidulites is one of those mysterious taxa that has been moved around a lot in it's classification.  Like its relative Cyclocrinites, it was considered to be a possible echinoderm, then it was thought to be a sponge, and these days it is generally thought to be a dasycladacean alga.  However it is still listed as a "porifera" in some databases, such as MCZbase.  

 

Don

[FossilNerd]

You had me at Ordovician...  Nice report and decent finds.  Congrats on finding the exposure. Good luck on your future hunts there! 

[Pagurus]

Impressive sleuthing, Dave. You made a great start! Thanks for posting your hunt.

[Shamalama]

16 hours ago, grandpa said:

I have had an experience with "dormant" poison ivy that probably bears sharing. 

I was digging in a Central Texas creek bank for Eocene fossils.  In the summer, the bank had been covered with P.I. so I decided to come back in winter.  It was indeed winter when I returned, and no P.I. in site as all of the leaves were gone.  I was plowing thru a lot of roots in my excavation of the fossil lens I was working.  You have already guessed the outcome.  The roots were from the P.I. and gave me one of the worst reactions I've ever had to P.I.  The leaves may be gone, but the roots are anything BUT dormant. 

Be careful out there, nature can jump up and bite you even in the fall/winter. 

That is a very good point @grandpa. It was still cold enough for me to wear gloves and I was not ripping out any roots or branches.

[Shamalama]

15 hours ago, nala said:

Very nice report and finds!

Thanks Gery!

14 hours ago, FossilDAWG said:

Nidulites is one of those mysterious taxa that has been moved around a lot in it's classification.  Like its relative Cyclocrinites, it was considered to be a possible echinoderm, then it was thought to be a sponge, and these days it is generally thought to be a dasycladacean alga.  However it is still listed as a "porifera" in some databases, such as MCZbase.  

 

Don

Yeah, but I still want to find some! Thanks for the info.

 

14 hours ago, FossilNerd said:

You had me at Ordovician...  Nice report and decent finds.  Congrats on finding the exposure. Good luck on your future hunts there! 

Thanks!

 

12 hours ago, Pagurus said:

Impressive sleuthing, Dave. You made a great start! Thanks for posting your hunt.

Thank you, I do like to research and find hidden spots.

[FranzBernhard]

@Shamalama, I like your trip reports very much! Exquisite pics, informative text with background info and last but not least - some fossils!

Thanks for sharing your adventures with the rest of the world!
Franz Bernhard

[Shamalama]

21 hours ago, FranzBernhard said:

@Shamalama, I like your trip reports very much! Exquisite pics, informative text with background info and last but not least - some fossils!

Thanks for sharing your adventures with the rest of the world!
Franz Bernhard

Happy that I can provide suitable entertainment for you.   Your trip reports are always entertaining as well, keep up the good work!

[Monica]

Congrats on finding a new fossiling site!  Keep us posted of your finds, especially if you find the Nidulites that you're looking for 

[Jeffrey P]

On 12/28/2019 at 4:45 PM, grandpa said:

I have had an experience with "dormant" poison ivy that probably bears sharing. 

I was digging in a Central Texas creek bank for Eocene fossils.  In the summer, the bank had been covered with P.I. so I decided to come back in winter.  It was indeed winter when I returned, and no P.I. in site as all of the leaves were gone.  I was plowing thru a lot of roots in my excavation of the fossil lens I was working.  You have already guessed the outcome.  The roots were from the P.I. and gave me one of the worst reactions I've ever had to P.I.  The leaves may be gone, but the roots are anything BUT dormant. 

Be careful out there, nature can jump up and bite you even in the fall/winter. 

I agree. I got a severe case of poison ivy the first time I visited the old Granton Quarry site in North Bergen, N.J. It was November and looked relatively safe. The site is totally off limits when poison ivy has leaves and great care must be taken even in winter. I try to make sure my hands are completely covered and once I return home I shower with Technu.

[Jeffrey P]

Congratulations Dave on your site research. I find your post and pictures interesting. The only Ordovician site I've been to in Pennsylvania is the one near Antes Fort. I know there are others but that would take some hefty research. Glad you're willing to do so. 

[Shamalama]

On 12/30/2019 at 8:14 AM, Monica said:

Congrats on finding a new fossiling site!  Keep us posted of your finds, especially if you find the Nidulites that you're looking for 

Thanks Monica!

11 hours ago, Jeffrey P said:

Congratulations Dave on your site research. I find your post and pictures interesting. The only Ordovician site I've been to in Pennsylvania is the one near Antes Fort. I know there are others but that would take some hefty research. Glad you're willing to do so. 

I've never been to that site but intend to at some point. Maybe if this mild winter continues I will have luck in the near future.