Jump to content

The Upper Ordovician Nautiloid Beds of Graf, Iowa


Nimravis

Recommended Posts

Two weeks ago while I was at the ESCONI Fossil / Mineral Show, I bid on and won a great little piece of rock that was identified as Isorthoceras sociale Cephalopods from the Upper Ordovician - Maquoketa Formation of Graf, Iowa. I did a little research before heading out to the MAPS Show yesterday and decided on my way back home, I would take a 1 1/2 hour detour to Graf and see if I could find this small road cut. I have to admit that this approximately 300 ft long road cut contains what must be some type of mass Nautiloid death bed. There are so many of them that you will for sure go home with your fair share if you ever get a chance to visit the very out of the way place that is hidden among farmland. I will give a couple warnings for this location- there is no shoulder to park on and you have to drive on the grass/dirt area that is muddy. Secondly, people have under cut these Nautiloid beds and there are TONS of rocks above your head in sections of this road cut; It is not a place for young kids nor a place for a Risk Taker. Besides the Isorthoceras sociale that I found, I also found a couple nice Gastropods. This is a place that I will not visit again since I did collect enough loose pieces and blocks that I found around the area.

 

Here are some pics of the area as well as some of my finds:

 

IMG_1990.jpg.16d75e06ae9cf10cedd93d38bb0db014.jpgIMG_1991.jpg.8c5ea9750616fc784a220ef994a84e37.jpgIMG_1992.jpg.2d247efc551d6443729a9a677a636a04.jpgIMG_1974.jpg.9bbd835fd2168e69122c42a052c553cd.jpgIMG_1939.jpg.3399a41a350a73e9db62e4f2aa00ebe8.jpgIMG_1948.jpg.b0292610aecc91986922d59954f0776c.jpgIMG_1952.jpg.e520071b3bbeac8ffa4fe43c74cc6aa7.jpgIMG_1956.jpg.b3c36167750c32e16a6968d6ce938b6c.jpgIMG_1965.jpg.bd72fe567a419cc58c39f70696f90ace.jpgIMG_1973.jpg.8b116f96b8ffe257c81cb109bd39a851.jpgIMG_1978.jpg.a8e95d21d3265004bc3c9936eb6a7a8d.jpgIMG_1979.jpg.2f462d025b88801a6fe18d589d5e5fcb.jpgIMG_1985.jpg.99f67f1f40da2a4dc0a3d7706a157ebb.jpgIMG_2010.jpg.c4ecf8e16a2227871c599a09f3d8c120.jpgIMG_2008.jpg.f100244a3853cd408705995c65a6943c.jpgIMG_1994.jpg.b54c598ab9d4710de1585e58c0d05c60.jpgIMG_2009.jpg.eca02a814b887ff4ad8a65543e03bcc6.jpg

IMG_1980.jpg

Link to comment
Share on other sites

Glad you were able to collect some pieces without getting hurt. It does look a bit of a dangerous place to hunt.

Dipleurawhisperer5.jpg

I like Trilo-butts and I cannot lie.

 

Link to comment
Share on other sites

11 minutes ago, Foozil said:

Woah. Thats a lot of nautiloids. Very nice finds.

Yes it is, and that is only a few pieces of what I collected.

 

7 minutes ago, Darktooth said:

Glad you were able to collect some pieces without getting hurt. It does look a bit of a dangerous place to hunt.

Yes, It appears that it can be a dangerous place.

Link to comment
Share on other sites

Nice nautiloids!  Thanks for sharing your little adventure with us, Ralph!

Link to comment
Share on other sites

A lovely cluster of nautiloids, Ralph. :) And fantastic site photos... Definitely many of us would feel like we were in our element at a location like that. :dinothumb:

...How to Philosophize with a Hammer

 

 

Link to comment
Share on other sites

Did you see any deep tire tracks in the mud? Another member just visited Graf and got stuck. Felt sorry him . He had planned an early April trip with his family to fossil hunt through out Iowa and ran into troubles. What a start to April! Maybe he will post his "adventures"!

 

Nice finds. I had posted once asking for explanation as to why there are so many cephalopods at the Graf road cut. It is not a certain layer but  all strata 10 feet thick!!!

Link to comment
Share on other sites

Great finds. While doing some research for a display of cephalopods, I read that modern squids do  mass mating and males and females die soon after mating. Large numbers of Belemnites are frequently found together and this is supposed to be the reason. However, the theory the Nautilius is the only surviving externally shelled cephalopod is that it reproduced a number of times in its lifetime versus the ammonites which sexually matured, then reproduced, and then died. Also that the Nautilus laid its eggs on the ocean floor versus ammonites setting them free to float with the plankton and thus were killed off with the meteor impact event.  Interesting that there is 10 feet of what looks to be differing types of sediment with orthocones throughout. Wonder if this was a special place in the sea where nautili returned to mate? Did you ever get an answer to your question as to why so many there? Might be a good place for a paleontology students thesis. I am curious, what types of rocks make up this location. What an unique site. Thanks for sharing it. One additional question, I thought in looking at your pictures that some might have the original nacre covering but could not tell for sure. When I searched the net, I found a number of articles about these fossils having the nacre preserved. However none gave any explanation about the exceptional concentration of the cephalopods.

Link to comment
Share on other sites

9 hours ago, Nimravis said:

I will give a couple warnings for this location- there is no shoulder to park on and you have to drive on the grass/dirt area that is muddy. Secondly, people have under cut these Nautiloid beds and there are TONS of rocks above your head in sections of this road cut; It is not a place for young kids nor a place for a Risk Taker.

Why does seeing your images of this cephalopod motherlode somehow bring this to mind?

 

mouse-trap-bait.jpg

 

Looks like it was a fun place to track down and hunt (safely). Glad you got to see that unbelievably dense collection of nautiloids and add some to your collection.

 

 

Cheers.

 

-Ken

Link to comment
Share on other sites

Wow thats a cool spot.  Must have been very exciting seeing the concentration, a collectors dream.  Thanks for the pictures,

Link to comment
Share on other sites

@Bobby Rico , @Manticocerasman , @Monica , @Kane , @Troodon thanks for the nice comments.

 

@minnbuckeye - I did see some deep tracks and yes, it is very easy to get stuck there- not to mention, there are very few cars that pass by and I would not always rely on cell service, I had one bar on my phone.

 

@fossilnut thanks for the great info.

 

@digit Ken, you are correct and I do not fear for my safety when I am outside rock climbing and I am 800 feet off of the deck or free climbing 30 foot boulders as much as I did collecting at this site.

Link to comment
Share on other sites

 NIMRAVIS I came across 1996 Geological Society of America Special Paper 306 on the Graff, Iowa nautiloids. Lead author is William Raatz.

Title is:

"Depositional Environments and Sequence of Stratigraphy of upper Ordovician epicontinental deep water deposits, eastern Iowa and southern Minnesota."

 

LINK TO PAPER

 

On page 146,"Many individual orthocones display an phenomenon of telescopic nesting where 1 or more...are deeply imbedded through the septa of another".

Read page 153 , which theorizes that about the multiple mass mortality events represented there and how the implosion of one individual's septa caused a vacuum sucking in  another individual.

 

Wow what a very unique and strange sequence of events are preserved there. There was another article that I don't subscribe so can't download it. It may be of interest: "Paleoecologic observations on the orthoceratid coquina" https:/pubs.geoscienceworld.orgpalental/article-abstract/29/3/  Vol 29 number 3  Hope these are helpful.

 

 

 

 

Link to comment
Share on other sites

Great photos of the road cut and a great haul. :)

Can't fail to find good orthocones there it seems, unless you get squashed by a rockfall. 

I've got a couple of these Isorthoceras, thanks to a kind Secret Santa. 

But those gastropods are great, too. 

Thanks for posting, very interesting mass mortality over a long time period. 

Life's Good!

Tortoise Friend.

MOTM.png.61350469b02f439fd4d5d77c2c69da85.png.a47e14d65deb3f8b242019b3a81d8160-1.png.60b8b8c07f6fa194511f8b7cfb7cc190.png

Link to comment
Share on other sites

That place looks loaded! Bucket list....? :D

Every single fossil you see is a miracle set in stone, and should be treated as such.

Link to comment
Share on other sites

15 hours ago, minnbuckeye said:

Did you see any deep tire tracks in the mud? Another member just visited Graf and got stuck. Felt sorry him . He had planned an early April trip with his family to fossil hunt through out Iowa and ran into troubles. What a start to April! Maybe he will post his "adventures"!

 

Nice finds. I had posted once asking for explanation as to why there are so many cephalopods at the Graf road cut. It is not a certain layer but  all strata 10 feet thick!!!

 

Lol that member he is referring to is me. The kids did get a kick out of my mom stepping on the gas when I was trying to tell her to stop and it was raining mud on me. For anyone visiting the site I definitely recommend not trying to park next to the cut. Some day I will try to post about my trip their albeit less pictures as my phone had died. 

Link to comment
Share on other sites

@Nimravis when I saw that piece get auctioned off he was claiming you couldn't find them any more there. I was a little worried after hearing that but literally stepped out of my van and realized that he was just trying to up the price obviously.

Link to comment
Share on other sites

12 minutes ago, smt126 said:

@Nimravis when I saw that piece get auctioned off he was claiming you couldn't find them any more there. I was a little worried after hearing that but literally stepped out of my van and realized that he was just trying to up the price obviously.

Yes- and the nice little piece I picked up at the silent auction for a couple dollars.

Link to comment
Share on other sites

4 hours ago, MeargleSchmeargl said:

That place looks loaded! Bucket list....? :D

It is like the Conasauga   :)

Link to comment
Share on other sites

I’m with @MeargleSchmeargl. If I am ever up that way I must take a detour. I’d love to go there.

That is an awesome place!!! Wow! I’ve never seen anything like it for cephalopods. Very cool. Thank you for sharing your trip. Love the pics.

 

@fossilnut I’m not sure about the mating one time and then dying. Some of them can get huge. My dad lives near Fayettevile, Arkansas and there have been a couple very large orthoceras found there which were in the 5-6 feet range. Also, someone posted a fragment of one on here a month or so ago from SE Kansas that was quite large. I suppose there could have been some physiological or anatomical problem that prevented those individual specimens from mating, but that seems like it would be a very rare occurrence.

Regarding ammonites on the same topic. I’m rather skeptical they only mated once when they come of age and then died, because some of the ones we find in Texas are enormous, over 40 inches.

Someone from the Dallas Paleontological Society told me that one of the members had found a 6 foot one in Texas once. Then there is one 8 foot 6 inch one found in Munster, Germany. I’m not sure how such great size can be explained if they can only mate once and die. There must be more to the story. I do know some species mate and die. I don’t question that. But how would we get the monstrous sizes if it were so? If they lived now we would have ammonite tales like we have shark, alligator and crocodile stores. They’d be big enough to devour a human.

 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...