Jump to content

Really cool pattern, poss crinoid stem?


Recommended Posts

Lone Hunter

From what I've learned crinoids aren't from around here,  prob from way upstream fill rock. Here being Dallas creekbed in Eagle Ford shale.   Its so unique with the patterns, almost looks carved, just guessing part of a crinoid because of the cylinder shape.  What the heck is it?

IMG_20210228_221447545.jpg

IMG_20210228_221415910.jpg

IMG_20210228_221351335.jpg

IMG_20210228_221321552.jpg

Link to post
Share on other sites
Tidgy's Dad

Yup, crinoid stem cross sections. Nice. :)

Link to post
Share on other sites
Lone Hunter

:zzzzscratchchin: If only I could cut it out to make a peice of jewelry!  Thanks so much for confirming, yay got it right!

Link to post
Share on other sites
FranzBernhard
1 hour ago, Lone Hunter said:

If only I could cut it out to make a peice of jewelry!

Whats your idea? If it is limestone, you can possibly do it with hand tools. Would you like to show us what you like to do? Whats your resources, what do you already have?
Franz Bernhard

Link to post
Share on other sites
DPS Ammonite

What does the other side look like?

 

I have never heard of crinoid stems from the Cretaceous in the Dallas area. I does not look like crinoid stems even if it is a brought in piece. I do not see any clear disks, only irregular fracturing. The white does look like a carbonate with at least 3 different good cleavages. 

Link to post
Share on other sites
Lone Hunter

I previously mentioned that it isn't from around here, it's washed downstream from the north,  and may likely be fill rock like someone else informed me.  But I do find them around here, inc. pics of others.  As far as what I would make I have no idea, probably a pendant, have no good recources that would work, just wishful thinking.

IMG_20210301_015216010.jpg

IMG_20210301_015831548.jpg

IMG_20210301_015749184.jpg

IMG_20210301_015252865.jpg

Link to post
Share on other sites
Rockwood
2 hours ago, Lone Hunter said:

 If only I could cut it out to make a peice of jewelry!

Angle grinder with a four inch tile saw blade. Careful though, they may not look like teeth, but they can bite. :)

  • Enjoyed 1
Link to post
Share on other sites
FranzBernhard
9 minutes ago, Lone Hunter said:

just wishful thinking.

Good start! Maybe you will have a more precise idea with time, maybe not.

 

Concerning the two other specimens, the bright one indeed looks like a piece of a crinoid stem. The dark one, however, looks more like a piece of an orthoconic nautiloid. 

 

Franz Bernhard

Link to post
Share on other sites
FranzBernhard
1 minute ago, Rockwood said:

Careful though, they may not look like teeth, but they can bite.

Indeed, especially if treated with an angle grinder ;).

Franz Bernhard

Link to post
Share on other sites
Lone Hunter

Definitely don't have an angle grinder, but now I know what I need, maybe I'll run across someone who has one. As far as being a nautiloid it does indeed look like that except the little bumps, was trying to account for those as worn down broken off cirri or holdfasts.

Link to post
Share on other sites
FranzBernhard
13 minutes ago, Lone Hunter said:

except the little bumps, was trying to account for those as worn down broken off cirri or holdfasts.

You are correct, these are not consistent with nautiloid.

Franz Bernhard

Link to post
Share on other sites
Lone Hunter

Appreciate your input, Its a steep learning curve and I just try to be as observant as poss and research what I can. I was even thinking it could be older than Cretaceous.  Look forward to other opinions.

Link to post
Share on other sites
Lone Hunter

Ran across this in an old forum post, it's a trans cross section of criniod stem showing interior, very similar to what's on the rock.  Thought I'd throw that out there.

post-18968-0-29987400-1441920764_thumb.jpg

Link to post
Share on other sites
Lone Hunter

Almost forgot pic of back side .

IMG_20210301_015132052.jpg

Link to post
Share on other sites
Rockwood
5 minutes ago, Lone Hunter said:

Ran across this in an old forum post, it's a trans cross section of criniod stem showing interior

I believe the pattern is actually a common form of recrystallization of the mineral in crinoid ossicles.

  • I found this Informative 1
Link to post
Share on other sites
Lone Hunter

That has my vote!  Thanks!

Link to post
Share on other sites

@Lone Hunter

 

As I mentioned in another of your posts, these crinoid bearing rocks have been trucked into the Dallas / Fort Worth area in many places and used for erosion control in some local creeks and rivers.  They are not native to the DFW area.  As they break apart over time, some of the individual crinoid bits get mixed with fossils from the local bedrock.  ;)

 

@bone2stone

  • Thank You 1
Link to post
Share on other sites
DPS Ammonite
6 minutes ago, JohnJ said:

these crinoid bearing rocks have been trucked into the Dallas / Fort Worth area in many places and used for erosion control in some local creeks and rivers.  They are not native to the DFW area.

Any idea where they are from?

 

With all the great crinoid stem fossils from north Texas, this is a very poorly preserved example.

Link to post
Share on other sites
Lone Hunter

 I believe I mentioned where they are from, and you may think poorly preserved but I think it's a facinating form of preservation.

Link to post
Share on other sites
Rockwood
9 minutes ago, Lone Hunter said:

facinating form of preservation.

It's one of those things that is best taken in small measure though. Often where the preservation is like this one ends up feeling like the focus is just out of reach.

Link to post
Share on other sites
4 hours ago, DPS Ammonite said:

Any idea where they are from?

 

My guess would be quarries in Wise or Parker counties.

Link to post
Share on other sites
Lone Hunter

Oh boy you are being really specific !  How on earth do you learn these things?  Tromping around quarries, studying rocks from known origins? Just curious.

Link to post
Share on other sites

It isn't economical to truck rock great distances.  The closest quarries with bedrock that age are in those counties.

Link to post
Share on other sites
Lone Hunter

Thanks for the lesson!

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...