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RickN

Found in my yard..Coral?

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RickN

I found this in my yard while cleaning up rocks. I dont know anything about fossils, but this looks like it was alive once. I live near the Chesapeake bay in Maryland.

 

15244361487878369096772760575477.jpg

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RickN

Sorry if I didn't post this in the right place...not good with forums.

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ynot

Welcome to TFF!

Yes, that is a tabulate coral.

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abyssunder

It's a coral, of course. It could be scleractinian, but I'm not familiar with the corals of that region. Wait for other opinions.

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RickN

Thank you so much for the quick responses, I look forward to hearing more..

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RickN

It's about the size of a clementine 

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WhodamanHD

I agree with what’s been said thus far, can I get a bit more specific on location? County or perhaps which town your nearish to? Helps with age, just from looks not thinking Miocene. 

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RickN

Howard county, south of Baltimore. Near the Patapsaco River. Sea level. My house was built in 1934. The stone came from a quarry in Westminister. I found it near the foundation so it could have come with the stone that built the house.

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RickN

I really dont know much about fossils at all, but from what I see, your right, most Maryland stuff seems to be Miocene, which i agree this does not appear to be.

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MeargleSchmeargl

100% coral, know that much. Aside from that, I have no expertise.

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RickN

The stone that was primarily harvested in that quarry is flagstone.

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WhodamanHD

Westminster is mostly schist and greenstone mixed with quartzite. However there some diabase, none of these hold fossils though so that rules the foundation out. From the location you gave, metabasalt or some other metamorphosed igneous rock is likely the bedrock, which doesn’t hold fossils, or dinosaur-aged sands and clays which would be terrestrial (So no coral). Pleistocene saw receding of water and encroachment of glaciers in Maryland, so I don’t see that as the source of this coral. I say that this piece has been brought in by humans, some previous owner went to the beach and brought it back as a souvenir. Ended up in the yard somehow, to be found by you years later. 

This is, however, a guess.

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RickN

With my family history, it could have come from Atlantic city in the late 1930s if it was brought it from somewhere else.

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RickN

They used to live there / vacation 

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RickN

A lot of clay in the area. Natives in the old days. Found quite a few arrowheads over the years. Wonder if they brought it in from somewhere.

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Plax

have found coral as ballast stone near the shore of both the Delaware and Cape Fear rivers. I believe that most of it is from the trade with the Caribbean for rum in the 1700s and early 1800s. Perhaps one of our experts can identify this as a Caribbean species?

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EMP
14 hours ago, RickN said:

Howard county, south of Baltimore. Near the Patapsaco River. Sea level. My house was built in 1934. The stone came from a quarry in Westminister. I found it near the foundation so it could have come with the stone that built the house.

 

It is definitely NOT a Pleistocene aged coral if it comes from Maryland. There are next to no marine Pleistocene units in the state, with only a few members of the Columbia Group being nearshore deposits. However, our climate was not conducive to such creatures, and no corals are known. 

 

Westminster is in the Westminster Terrane of the Piedmont, and it's geology is almost exclusively the schists, phyllites, and other metamorphic rocks of the Marburg and Ijamsville Formations. There are some quartzite ridges nearby the town, but those are just layers present within the Marburg. There is the Silver Run Marble member of the Marburg, however no fossils are known from it, and it is an early Cambrian-late Proterozoic unit (incapable of producing corals). The only sedimentary rocks nearby Westminster are the deposits of the Newark Group (terrestrial Triassic rocks, so it can't be that) and the Cambrian Araby Formation and Frederick Limestone (too old for corals). As such, it likely does not come from this quarry. 

 

Howard County lies predominantly within the Baltimore Terrane rocks of the Glenarm Group and Baltimore Mafic Complex. The Glenarm contains the metasedimentary Setters Formation (early Cambrian) and Cockeysville Marble (early (?) Cambrian), however no fossils are known from either (well, I believe someone a few years ago claims to have found extremely fragmentary crinoid/echinoderm fossils in the Cockeysville, but those were pieces of individual columnals and I personally don't think they are anything). The Baltimore Mafic Complex has no fossils. Now, eastern fringes of HoCo around Jessup do have Potomac Group bedrock, and the Potomac Group is locally abundantly fossiliferous (early Cretaceous). However, the Potomac Group is terrestrial, not marine, and thus one wouldn't expect it to produce marine fossils (I have found a piece of Devonian shale with a spiriferid shell imprint in it and a piece of Cambrian sandstone (likely Antietam Sandstone) with a Skolithos linearis in it at the site I collect in that exposes the Patuxent Formation, however both those pieces were very weathered and this likely was not deposited by the early Cretaceous streams and rivers). 

 

To me this indicates that your fossil comes from the stone that formed the foundation of the house, assuming that that is a different stone from the one coming from Westminster. Another possibility is that it could have just been left in the yard by previous occupiers of the home. At this point it's pretty hard to nail down a solid ID for it, but if I had to make a guess I'd say it's at least Cenozoic in age (so no more than 65 million years old). 

 

 

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FossilDAWG

This looks very much like the colonial scleractinian corals that make up much of the limestone exposed in the Florida Keys and the area south of Miami.  Herb's suggestion of Solenastrea is a good one.  This material used to be quarried for building stone and fill.  How a chunk made it's way to Maryland is anybodies guess, it might have been picked up by someone on vacation in Florida or it might have been used as ballast, or it might have been some other process. However it got there it is certainly a transplant.

 

Don

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RickN

Just looking around at some different pics. Could it be a sponge?

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abyssunder

No, it's not a sponge, it's a scleractinian coral. You can see the septal arrangement in the corallites.

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