GuidesMagazineShopBuy FossilsJoin Hunts
easterly
I attach a couple more pics of Happisburgh sea-defence rocks which may be of general interest; Pete and Prep01 have identified the rock as limestone.

The first pic shows a section, roughly several inches across, of very dense shell fragments. The sizes range from a couple of millimetres to roughly 1.5 inch/4cms. The band of fragments is roughly 12 inches/30cms wide.

The second pic, from the same rock, shows a section roughly 6 inches/15cms across. Some very fine plant matter(?) ranges across the centre of the photo. Any suggestions on what it is would be appreciated.

DSC_4351.jpg  DSC_4336.jpg 

Hope these are of interest,

Alan
Quote 1 0
Dirty Pete
Can't really resolve much of your fine plant matter in the pic but suspect it might be a Bryozoan.
Does it look something like this?
fenestratesmedium.jpg 
Pete
Quote 1 0
easterly
Thanks, Pete

There is an echo but not a strong one.

'My' plant matter emanates from bottom right roughly two-thirds of the way across the pic. It's roughly triangular, with 'stalks' radiating outwards. At bottom left the matter between the stalks often shows a sort of cellular grouping. Perhaps that's where the plant has moulded onto the shelly matter. In the finest detail individual 'cells' are visible in the same way as your photo. The whole thing is surprisingly complete but difficult to see - I'll admit I didn't notice it until I got my original 22MB jpeg up on my big monitor!

With that in mind, I'll go back and do smaller files because it is interesting. I find scaling-down the maximum resolution originals by halving them in steps to 1MB, which is then halved again by the website, leaves the pictures looking a bit nuked. Other people can post clear, crisp, sharp photos so I must be able to as well🙂

Alan
Quote 0 0
Dirty Pete
All I can suggest then is some kind of Carboniferous marine encrustation.

Pete
Quote 1 0
prep01
Hello Alan. I don't see any evidence of 'plant' material in any of your photos. Limestone is almost 100% marine. I think what you are looking at are shell fragments and partial crinoids which although are known today as 'sea lilys' are in fact animals in the 'echinoderm' family.
Colin Huller
Quote 1 0
Brittle Star
I agree with Colin. This compressed seabed, detritus on the deep sea floor. Pressure over millions of years equals limestone. Plants are preserved in terrestrial or shallow water sediments, so you should look for plants as carbon layers in land sedimentary rock 
JW

 Never ask a star fish for directions
Quote 1 0
Dirty Pete
Obviously not plant matter, but looks like plant matter to Alan. I can see the triangular area he's talking about and it seems to have a lacy/dendritic appearance. Hopefully he can get a close up pic of the structure to confirm whether its something or nothing.

Pete.
Quote 1 0
Bill G
Closeup looks bryozoan like to me
CF2274AF-94D0-4F1B-8FFF-7B133E9AA6C5.jpeg 
Cheers, Bill
Quote 1 0
Barrow Museum
I agree...that was my first impression as well.  The  earlier picture of a Productid brachiopod in what looks just like Carboniferous Limestone from this Happisburgh coastal defence supports the notion of what has been written above, though did not entirely rule out the possibility of Upper Permian, Magnesian Limestone, particularly if there was an abundance of bryozoa.  However, I see no sign at all of any dolomitization.  But what puzzled me is the pattern of more circular shapes to the lower left even further, which could be transverse sections of a compound coral as well. I can see a network of corallites, a columella in each and rings of dissepiments. What we are seeing as bryozoa could in fact be longitudinal sections of dissepiments.  Might this be Lithostrotion (or whatever it is now called?)
Anyone care to comment?

Bryo_coral.jpg   Click image for larger version - Name: Bryo_coral.jpg, Views: 11, Size: 100.40 KB
Quote 1 0
Dirty Pete
Hi BM,
Looked a bit 2D hence the bryozoan theory but now you mention it they do look like closely packed corallites ,hard to get a handle on the scale and orientation of the colony/colonies though. Maybe some kind of dome shape with corallites radiating out from a centre. Would be nice If Alan could get some unfuzzy close ups to confirm one way or the other.

Pete.
Quote 1 0
TqB
I agree with Barrow Museum, that one is a Lithostrotion. (The honeycomb ones are still called that - it's the branching ones that are Siphonodendron and Diphyphyllum. Not always very satisfactory as you get both Siphonodendron and Lithostrotion habits in the same colony sometimes!)
Tarquin
Quote 1 0
easterly
Thanks so much for all the interesting responses.

I'm going to upload two freshly-taken pics. The first is an overall view of the Lithostrotion(?) which measures roughly 4"/10cms on the longest side and roughly 3.5"/8.5cms on the widest point. The second is a closer shot of the bottom left area mentioned by Barrow Museum - your mention of coral looks right for the circular structures.

Alan

Hborophone.jpg  DSC_6457 2.jpg 
Quote 0 0
Dirty Pete
Hi Alan,
Here's one of Tarquin's specimens from the excellent Carboniferous corals thread on this site.
IMG_1280_-_Copy_1a.jpg 
Lithostrotion decipiens.

I think it's pretty conclusive.

Pete.
Quote 1 0
Bill G
Hi Alan 
I’ve enlarged part of your last pic
9711BDA9-B4DF-40AE-888D-73244F73E23E.png 
Cheers, Bill
Quote 1 0
Gary W
Looks like ty,pical carboniferous limestone coral / crinoid mass
Gary
Quote 1 0
easterly
My thanks to everybody - your comments and extra pictures have been very useful.

Alan
Quote 0 0
Write a reply...


Discussions on fossils, fossil hunting, rocks, locations, and identifying your finds.
(C)opyright 2019 - UKGE Ltd and UK Fossils - Contact us