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Tagged: martinsburg formation, Ordovician
- This topic has 6 replies, 3 voices, and was last updated 6 years, 8 months ago by
Jayson Kowinsky.
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January 30, 2017 at 9:59 pm #18464
Hunter Thurmond
ParticipantI found this in the southern portion of the Massanutten mountain system, I think in martinsburg formation ordovician
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You must be logged in to view attached files.January 30, 2017 at 10:16 pm #18466Jack Kallmeyer
Moderator@hunter-thurmond My first guess is some kind of coral. But I am not very firm in that belief so I would like to hear what others think. Is this thing really small or is that woven background made of giant thread?
January 30, 2017 at 10:37 pm #18467Hunter Thurmond
ParticipantMy first guess was coral as well. The background is typical carpet, so yes it is quite small maybe 4-6 mm. To me it seems to leave a trail to the right or a shadow where sediment was blocked. It ws found at the base of a landscaping tree, a clump of shale caught in the root mass, so whether or not it is actually from martinsburg shale is also questionable. I thought it looked similar to this picture
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You must be logged in to view attached files.February 1, 2017 at 7:50 pm #18499Jayson Kowinsky
ParticipantHello,
Ya, it’s the very top of a solitary coral. I have seen lots of those in the Needmore formation in Virginia. Although it’s a different formation and time period, I’m sure they can be found in other formations. I attached a picture from the “Lost River” site on my webpage. This one, the very tip was visible like yours, and I extracted the rest of it to see what it was.
I have no clue about the genus, I can’t seem to find much info on them in the literature.
Later!
Jayson
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You must be logged in to view attached files.February 1, 2017 at 8:04 pm #18502Jayson Kowinsky
ParticipantHey, I just saw that a member of the Needmore formation in West Virginia and Pennsylvania is the direct equivalent of the Onondaga Limestone in NY. I wonder if your fossil came from that, or a layer just above or below the limestone?
About your size. The one I attached as the picture is the biggest one I’ve found. Most of them are very small, like yours.
Later,
February 2, 2017 at 7:27 am #18504Hunter Thurmond
ParticipantIs the Needmore formation also equivalent to the Mahantango formation, in Virginia? @jayson-kowinsky
February 2, 2017 at 9:02 pm #18510Jayson Kowinsky
Participant@hunter-thurmond – No, the Needmore formation is not equivalent to the Mahantango. However, they are very similar.
They USED to be part of the same group. Now, the Mahantango is part of the Hamilton group, while the Needmore shale is part of the Onondaga Group.
Looking at the stratigraphy, the Magantango is on the top, the Marcellus shale is in the middle, and the Needmore is below the Marcellus. (I attached a picture of the stratigraphy.)
The Magantango is a few million years younger than the Needmore. Also, the depositional environment was a little bit different, as the Needmore is composed of soft oily gray calcareous shale, while the Magantango is composed of siltstones and sandstones.
With that said, they are of similar age, and they do have similar fossils.
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