upper campanian marine fossil from the nanaimo group in British Columbia

[bcBryan]

So I'm on my first fossil hunting trip ever. I found some obvious bivalves at one location but at another I'm not sure what I found.

Each piece is about 1.5 inches wide.

Found in the cedar formation which is upper Campania in the nanaimo group on Pender Island, British Columbia, Canada.

There are several similar pieces in the mudstone matrix in this location. Are they fossils?

Thanks

Edited July 21, 2016 by bcBryan

[Guguita2104]

Hello and welcome to TFF !

Try to compare it with some pics of belemnites (extint cephalopods:https://en.wikipedia.org/wiki/Belemnitida.

Regards,

[abyssunder]

I think, the specimen in question could be a calcareous concretion with a tubular core, considering that the Upper Cretaceous Cedar District Formation in British Columbia is composed of alternating shale, siltstone and sandstone and contains carbonate concretions.

" The Upper Cretaceous Cedar District Formation of British Columbia, composed of alternating sandstones, siltstones, and shales, contains carbonate concretions of varied shapes and sizes. Calcite is the essential component, but detrital grains are abundant where the concretions are located in silty or sandy beds.

Several features suggest that the concretions were formed immediately after deposition of the host sediments or shortly after shallow burial: (1) animal borings or burrows in the concretions filled with sediment from the host beds; (2) thickening of the host beds around the concretions; (3) the random orientation of some concretions with respect to bedding and lamination, and the stretching and folding of others where present in beds showing soft-sediment deformation; (4) undeformed bivalved shells enclosed in the concretions; and (5) the scarcity of grain to grain contacts among the included detrital grains, and the undeformed mica plates. The concretions probably grew by precipitation of CaCO3 near decomposing organic matter in reducing and high pH environments. " - Carbonate Concretions in the Upper Cretaceous Cedar District Formation, British Columbia - R. A. Rahmani http://archives.datapages.com/data/cspg/data/018/018002/0282.htm

Sedimentology and petrology of the cedar district formation : late cretaceous, southwestern British Columbia - Rahmani, Riyadh Abdul-Rahim https://open.library.ubc.ca/cIRcle/collections/ubctheses/831/items/1.0053084

[tmaier]

Try to compare it with some pics of belemnites (extint cephalopods:https://en.wikipedia.org/wiki/Belemnitida).

Regards,

Your link is busted... here is the corrected one... https://en.wikipedia.org/wiki/Belemnoidea

At first I saw this as a spherical object with a core, likely a concretion, but after you said belemnite then I saw that it might be a rod of a belemnite cone, and it is in an orthogonal cross section. Picking back some of the matrix to expose the fossil more will help figure this out.

[bcBryan]

Thanks for the replies. I have read all the links and a bit more which leads me to believe abbyssunder is correct and it is a concretion based on my other samples and photos as well.

The area has lots of concretions just most don't have any detailed structure like the one I posted. I've posted a photo of another interesting one for the curious.

Thanks again.

[FossilDAWG]

I agree that the specimen is a cross section of a typical elongated or tubular concretion, which are common in the Cedar District Formation and other Nanaimo Group formations. The center structure may be just a burrow, as is very common in these concretions. However it does bear some resemblance to a Baculites, and several species of Baculites (B. inornatus, B. rex, B. anceps, B. occidentalis, maybe others) are known from the Cedar District Formation. I think the concretion would be worth digging out and splitting further.

The specimen lacks the radiating calcite fibers typical of a belemnite guard. Also belemnites seem to have been absent from the North Pacific faunal realm in the Late Cretaceous, at least after the Albian (they are common in Aptian/Albian rocks). No true belemnite has been reported from any formation in the Nanaimo Group, nor from equivalent strata in Alaska or California. I'm pretty sure they were absent from Japan at that time as well. There is a related coleoid that has been collected on Hornby Island, but it looks like a belemnite phragmocone without the guard. The guard is actually present, but it is reduced to a thin covering over the phragmocone and you need a scanning electron microscope to see it. The specimen in the photo is certainly not a belemnite. The absence of belemnites is curious, as they were abundant in the North Atlantic realm throughout the Late Cretaceous.

Don

Edited July 21, 2016 by FossilDAWG

[Wrangellian]

Keep looking in that spot (look for shale especially), I have never been to Pender and the formations like Cedar District are less well-represented in collections around here (like mine) than is the Haslam Fm!

[bcBryan]

I am returning to the cedar formation site tomorrow. I'll try to dig out the pictured concretion(possible baculite).

I appreciate the encouragement to keep at it. I'll take lots pictures and get what samples I can.

Is it appropriate for this forum to post here with further finds or should I start a new thread?

[FossilDAWG]

Good luck! A lot of species have been reported from the Cedar District, although most are from Sucia Island which is a state park so collecting is by permit only. However I have a few fossils from outcrops on Denman Island near the ferry landing, and there are outcrops on some of the Gulf Islands and some rivers near Courtney.

I'd vote that you post here to keep things in one thread. It's easier for me to remember where to find them that way. It's up to you of course.

Don

[doushantuo]

regarding belemnite biogeography:

https://web.natur.cuni.cz/ugp/main/staff/sakala/04-divers/pavel/plenus/14-kostak.pdf

Anyone interested:look up Walter Kegel Christensen's work ,some of it in ACTA PALEONOLOGICA POLONICA(1997 being a good year)

http://journals.plos.org/plosone/article/asset?id=10.1371%2Fjournal.pone.0095632.PDF

Edited July 22, 2016 by doushantuo

[bcBryan]

I had a good day in the cedar district. I'm quite certain the pictured sample from the first post above is a concretion. We'll refer to.it as sample 1. I could not dig it out of the surrounding matrix in the time I had but there were several other very similar objects in the vicinity that were concretions.

Photo 1, below, is 1.5" high and 1" diameter. I wonder if it is a baculite. Sample 2.

Photo 2 is 1.25" across. A bivalve? Sample 3.

My prize of the day is the third photo below. A 3" amonite.sample 4.

Continued next post.

Edited July 23, 2016 by bcBryan

[Wrangellian]

Where is the next post?

You have done well.

#1 just looks like a concretion to me. Might be something inside it, judging by the tip. Long fossils such as bacs and scaphopods sometimes occur in elongated concretions like this.

#2 I can't tell. It's definitely something, probably bivalve as you say.

#3 Good find. Can't help you with ID as I'm not up on my non-Haslam fossils. If it can be ID'd, it could be important, as ammonites are important for stratigraphy, as are Inoceramid bivalves (Sphenoceramus, etc) and potentially other things. So be sure to record exactly where you find each fossil.

Edited July 24, 2016 by Wrangellian

[bcBryan]

Ok, I'm back to share my finds and get some help identifying them.

First up 3 elongated items. I have no idea what they are.

1 is 3" long.

2 is 2" long.

3 is 2.5 inches long.

Edited July 25, 2016 by bcBryan

[bcBryan]

Next up 2 photos of some structures I found in several places within a kilometer of each other. If I had to guess, I might say they are geologic.

Each bump is about half an inch on average.

I have a few more that I'll post tomorrow night.

Edited July 25, 2016 by bcBryan

[Wrangellian]

#1 and 2 are plant stems or twigs. I see identical ones on Mt Tzuhalem all the time. #3 not, sure, can you get better pics? (possible burrow)

No idea what that is in post 14! Do you think it continues into the rock or is it elongated like it appears?

[bcBryan]

Posted Today, 06:22 PM

#1 and 2 are plant stems or twigs. I see identical ones on Mt Tzuhalem all the time. #3 not, sure, can you get better pics? (possible burrow)

No idea what that is in post 14! Do you think it continues into the rock or is it elongated like it appears?

I'll take a better photo of #3 and post it tomorrow.

As for post 14, it continued into the rock. As I said I saw it several places. One example had the bumpy structure on both sides of the rock about 2.5" thick. I have one more photo which is attached. I think I kept one small sample but I've yet to unpack half my finds from the trip. I'll unpack it tomorrow and take photo and post it.

Edited July 26, 2016 by bcBryan

[bcBryan]

I've a few more stem or twig fossils but one last mystery from the cedar formation.(I also got a few fossils from the Pender formation to share later.)

The photo shows a branch like structure. There is a possible concretion in the upper right quadrant that the "branches" surround. The photo shows a 6" sample. I found it in a a loose rock I split open so no way to tell if it continued further.

It's hard to capture in the photo. If there is interest, I'll try for a better photograph tomorrow.

Edited July 26, 2016 by bcBryan

[abyssunder]

The last one reminds me of Thalassinoides burrows. https://www.google.com/search?q=thalassinoides&biw=1360&bih=612&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiOlueD2JDOAhWsKsAKHZ2PBigQ_AUIBygC&dpr=1

BEDROCK GEOLOGY AND STRATIGRAPHY OF THE LATE CRETACEOUS NANAIMO GROUP OF THE MAPLE BAY-COWICHAN BAY AREA, BRITISH COLUMBIA - David Dean White http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/42686/WhiteDavidDean1983.pdf?sequence=1

Edited July 26, 2016 by abyssunder

[Wrangellian]

I think abyssunder has it.

[bcBryan]

Thanks Abbyssunder,Thalassinoides makes sense.

I unpacked all my fossils from the trip and I don't have number 3 from post 13. So I guess that one will remain a mystery.

I have a few more to show. Only two tonight. Two remaining I couldn't get decent photos of so ill try again tomorrow in different light.

The first photo shows an area 1.5" wide.

In the second photo the light object is 2.5" long.

Edited July 27, 2016 by bcBryan

[Wrangellian]

Hard to tell... Can you take better pics, in direct sunlight, different angles, etc?

[bcBryan]

Hard to tell... Can you take better pics, in direct sunlight, different angles, etc?

Ok, I'll do that tomorrow.

[bcBryan]

Ok, here's a few more photos as requested.

Same item at different angles.

Edited July 29, 2016 by bcBryan

[bcBryan]

And here's 3 new photos of the other item.

[Monica]

Ok, here's a few more photos as requested.

Same item at different angles.

Hi bcBryan!

This picture (from post #23) looks like a barnacle to me (Order Sessilia, Suborder Balanomorpha - unstalked, non-parasitic acorn barnacle), but I'm not sure if these types of animals were common during the Upper Campanian. Hopefully someone else can help with identification!

Monica

Edited July 29, 2016 by Monica