Interesting Brachiopods Impressions

[Dianka]

Hello,

My brother was recently digging in the stream nearby his house, upstate New York, looking for some nice rocks to put in his yard, and have found this piece, which he later gave to me.

There are many impressions of some kind of Brachiopods on it.

My guess is they are Pennsylvanian period Brachiopods. Am I right?

Thanks!

Diana

[Fossildude19]

I recognize some of them as Mucrospirifer brachiopods.

Close guess, they are common from the Devonian period.

This from Wikipedia.

If you give the County/City found in, we could narrow down the time period, but it is probably Middle Devonian.

Nice hash plate.

Regards,

Edited August 7, 2013 by Fossildude19

[piranha]

The Paleozoic fossils in New York are older than the Pennsylvanian. This chart has an excellent list of NY fossils sorted by stratigraphic age and counties. LINK

 

 

 

 

[Missourian]

Nice brach slab. The source outcrop may not be too far upstream.

[Dianka]

I recognize some of them as Mucrospirifer brachiopods.

Close guess, they are common from the Devonian period.

This from Wikipedia.

If you give the County/City found in, we could narrow down the time period, but it is probably Middle Devonian.

Nice hash plate.

Regards,

Tim, thanks for the info. He found it in Hannacroix, Greene County.

[Dianka]

Nice brach slab. The source outcrop may not be too far upstream.

Actually, he found few other slabs, that were few times bigger than this one! But I'll tell him to look for some more Thanks!

[Fossildude19]

Tim, thanks for the info. He found it in Hannacroix, Greene County.

Thanks for the info.

This Bedrock Geologic map of New York State shows Greene County mostly in the Devonian era rocks.

Keeping in mind Stratigraphy isn't really my strong suit:

Since Leeds and North Coxsackie are closest to Hannacroix, we can guess that it is either the Hamilton or Onondaga formation, based on the link Piranha provided.

The Hamilton group is in the Middle Devonian, and I believe the Onondaga is Early to Middle Devonian.

Regards,

Edited August 7, 2013 by Fossildude19

[erose]

Looks like classic Hamilton Group brachiopods including Mucrospirifer.

[pinkpantherbeekeeper]

Cool hash plate!

[MarleysGh0st]

This Bedrock Geologic map of New York State shows Greene County mostly in the Devonian era rocks.

Keeping in mind Stratigraphy isn't really my strong suit:

Since Leeds and North Coxsackie are closest to Hannacroix, we can guess that it is either the Hamilton or Onondaga formation, based on the link Piranha provided.

The Hamilton group is in the Middle Devonian, and I believe the Onondaga is Early to Middle Devonian.

Using the GIS overlay for the Geologic units of New York with Google Earth, it shows Hannacroix as being Middle Ordovician, in the Austin Glen Formation. But the stratigraphy changes rapidly in this part of the state. East of the Hudson River, it becomes Cambrian. About 1/4 mile west of Route 9W, it's Lower Devonian, and a mile west of that becomes Middle Devonian. This is a case where one would have to check a very specific location to be sure.