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Hydrangea

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Reply with quote  #251 



 

 Hello Folks,

 

I have been following this thread with interest for a while now and have finally decided to join the forum.

I have picked up a few coral pebbles on various Yorkshire beaches and if I can get the hang of posting images I'll show what I've found.

 

coral_image41c.JPG 

Coralites to 2mm

 

 

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Reply with quote  #252 
Roy,

As a relative newcomer to this board myself, may I offer you a warm welcome. That's a very nice clean Siphonodendron (Lithostrotion) junceum you have found. I'dlove to see more of your finds.

Very best wishes

Alistair
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Reply with quote  #253 
 






Hi Alistair,

 

thanks for the warm welcome.

I don't know much about corals (yet!), but I love collecting them.

coral_image10c.jpg 

Coralites to 8mm.

 

 

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Reply with quote  #254 

Alistair, thanks for the sedimentation explanation, very satisfying work!

Roy, many thanks for joining in with those beautiful specimens.
Compared with Alistair, I'm a newcomer to coral ID myself; however... your second one has 23 major septa and apparently a single row of dissepiments which should make it Siphonodendron (Lithostrotion) irregulare according to this key:
http://www.app.pan.pl/archive/published/app25/app25-385.pdf







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Reply with quote  #255 









 

Another Yorkshire pebble.

I like the coloured corals, but these are usually poorly preserved.

coral_image_3d.jpg 

 

Coralites to 15mm ....reminds me of bonfire night!

 

 

 

 

 

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Reply with quote  #256 
From the Great Limestone (found in a track but from Weardale area) -

(I really don't know whether to call this Lonsdaleia duplicata or Actinocyathus floriformis; I believe it's a growth variant of floriformis (cerioid) but, as you're probably sick of hearing, the phaceloid ones are called Lonsdaleia and duplicata was the name for phaceloid floriformis when they were all called Lonsdaleia...)

It's starting to go cerioid in places anyway.

About 10cm across

IMG_2163_-_Copy.jpg 

IMG_2164_-_Copy.JPG 

IMG_2164_-_Copy_2.JPG 

IMG_2164.JPG 




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Reply with quote  #257 



Hi Roy,
Good timing! - that's a nice Actinocyathus floriformis. Beautiful preservation, you're right about the coloured ones, they seem usually to be heavily recrystallised.





Edited by TqB 2014-01-08 17:11:06

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Reply with quote  #258 


 

Hi Tarquin,

thanks for the ID and link.

You have posted some really good corals which have inspired me to post some of mine. Keep up the good work!

coral_image14f.JPG 

 

Coralites to 3mm.

 

 

 

 

 

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Reply with quote  #259 
Hi Guys

Beautiful specimens!!

Tarquin,

Thanks for making John Nudd's paper available. I've had this paper for a number of years and although now over 30 years old is still very relevant. I think your latest coral backs up Dorothy Hill's statement on Lonsdaleia (p.151) "....and consider the difference in growth form between fasciculate and ceriod to be too trivial a reason for generic separation". I think she got it right. I'm afraid I still favour Lonsdaleia floriformis. But then I'm old school!!!

Very best wishes
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Reply with quote  #260 


welcome hydrangea,,lovely coral fossils.. you have them looking great..
and tarquin-fantastic as ever sir
 
thanks for showing them

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Hydrangea

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Reply with quote  #261 
 

Thanks to all for the warm welcome and compliments.

Another Yorkshire beach coral pebble to show.

 

coral_image33c.jpg 

 

Coralites to 4mm.

 

 

 

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Reply with quote  #262 

Hi Roy,

Nice work, I think I'd call that last one Siphonodendron irregulare again, and your previous cerioid one looks like Lithostrotion decipiens.

I'd be interested to know how you're preparing the surfaces, are you sawing them first?




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Reply with quote  #263 
Alistair & Gary, thanks for the comments.

Alistair,it would certainly be a relief to just call them Lonsdaleia, I'm with you!

Actually, I've realised I was wrong to equate floriformis and duplicata, the axial structures are different for a start.
So here, with the old names, are what I think are the two species:

L. floriformis, phaceloid form, on the way to cerioid:
IMG_2164_-_Copy_1.JPG 


L. duplicata
, mostly phaceloid with occasional touching corallites
[attach:fileid=uploads/1483/Lons._duplicata_1__B_-_Copy_1.JPG]





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Reply with quote  #264 
This one I'm rather stuck on for a species.
It was picked up from the same path that the last specimen was, from the Great Limestone (basal Namurian).

It's a large Diphyphyllum, up to 12mm. Up to 30 major septa and an unusual looking dissepimentarium in some places. The largest species I can find listed from this bed is D. furcatum which doesn't look right.

Could be: D.concinnum (Lonsdale), D. ingens Hill.
Also very like diphymorphic Siphonodendron (Lithostrotion) proliferum in Hill, not a hint of a columella though.

IMG_2159_-_Copy.JPG 

IMG_2160_-_Copy.JPG 

IMG_2160_-_Copy_2.JPG 

IMG_2167_-_Copy.jpg 

IMG_2168.jpg 




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Reply with quote  #265 

Hi Tarquin,

some lovely corals you've found there, keep them coming!

 

I have a diamond saw and can easily cut up to about 10cm.

I slice the corals with the saw, then grind them down (wet) by hand with diamond sharpeners - the ones with brightly coloured plastic backs. Then I finish them off with very fine wet and dry and a quick polish on the buffing wheel on the bench grinder.

My early attempts were very poor and I almost gave up, but I persisted and I am continually improving.

I have polished round pebbles with wet and dry, but it is very slow and the surface is often deeply bruised.

 

Here's another yorkshire coral pebble, this time very odd preservation. It looks like a photo negative but it really is this colour.

 

coral_image18c.jpg 

 

Coralites to 5mm.

 

 

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Reply with quote  #266 
Roy, thanks for the prepping details, I hope to get a decent saw soon!

Love the preservation on that last one, another Diphyphyllum.



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Reply with quote  #267 


 

Yet another Yorkshire beach coral pebble

 

coral_image16c.jpg 

 

 

Coralites to 10mm.

 

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Reply with quote  #268 

That's a beauty, I've not seen one quite like it, looks like a Diphyphyllum but the septa extend further towards the middle than most.



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Reply with quote  #269 
 

Hi Tarquin, thanks again for the IDs.

A decent saw isn't cheap but once you've got one the running costs are low. I've been using the same blade for over 5 years now and cut hundreds of limestone rocks. I think my saw has been well worth the expense and I enjoy using it. It's always a thrill to cut open a rock and see what's inside. You need to consider carefully the blade size, make sure to get one big enough for your requirements.

 

Another Yorkshire beach coral, a common one but a nice one.

 

coral_image21d.jpg 

 

Coralites to 2mm.

 

 

 

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Reply with quote  #270 


 

Another Yorkshire beach coral pebble.

 

coral_image38f.JPG 

 

Nice dense coral, coralites to 8mm.

 

 

 

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Reply with quote  #271 


Those are beautiful! How much does a saw cost roughly?
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Reply with quote  #272 
Hi Tarquin,

Iƒ¢¢â€š¬¢â€ž¢ve been away for a couple of days so have not had a chance to respond to your latest specimen.

Of course it raises one of the perennial problems for coral workers ƒ¢¢â€š¬¢â‚¬Å“ is Diphyphyllum merely a diphymorphic form of Lithistrotion? I donƒ¢¢â€š¬¢â€ž¢t think so!! I donƒ¢¢â€š¬¢â€ž¢t think they are related at all. I think Diphyphylum is a distinct genus for a couple of reasons. The form of off-setting is different between the two and Lithostrotion does not change its form of off-setting when it becomes diphymorphic. ( For you guys just coming to corals, diphymorphic means septa withdrawing from, and losing, the axial complex). I believe (as Mƒ¢¢â€š¬¢â€ž¢Coy did in 1851) that Diphyphyllum is more akin to Koninckophyllum.

Turning to your specimen, the size of the corallites bothers me, and when you say there are changes in the disspeimentarium (do the dissepiments become lonsdaleoid?) It may be that you have a new species of Diphyphyllum. Is there any indication of off-setting? However I would like to see more examples with accurate horizontal and vertical sections before deciding on origins.

As always, great corals. Keep ƒ¢¢â€š¬‹Å“em coming!!!!

Very best wishes

Alistair
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Reply with quote  #273 
Blimey! Think I need to look up "a few" terms there!  


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Reply with quote  #274 

Thanks very much, Alistair. I'd read that Diphyphyllum is probably polyphyletic but hadn't realised that could include a non-lithostrotionid ancestry.

Parts of the dissepimentarium do look lonsdaleoid but it might just be the  preservation of a disintegrating normal one - see the LS in my third picture.

There
are a couple of possible offsets on this block but nothing unequivocal.
I'll look out for some more material and prepare some proper sections -
when I get my saw!

Thanks again for your interest!




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Reply with quote  #275 
And here's a good paperweight, found today on the North Yorkshire coast by my wife.

Lithostrotion vorticale, probably the the best preservation we've found  (drat her!)

IMG_2177_-_Copy.JPG 

IMG_2179_-_Copy.jpg 

IMG_2180_-_Copy_a.jpg 

Speaking of offsets, I like the budding corallite in the middle here:
IMG_2183_-_Copy.jpg 



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Reply with quote  #276 

 

Hi Keen Steve,

I started off many years ago using a cheap tile saw from a DIY store but this would only cut small stones.

My present saw cost around ƒâ€š‚£1500 five or six years ago but they are no longer manufactured.

Have a look in the UKGE shop (top right on this site), look under lapidary equipment, cutting machines to give you some idea of current prices.

If you are just starting out it may be worth joining a Lapidary club and use their equipment  or ask a friendly stone mason if it is just the odd rock you need cutting.

Have a look at the polishing fossils article in the hints and tips section.

Remember you can polish fossils by hand without sawing them but it is much easier to polish a flat

surfaces.

Best of luck and show us your results.

 

 

Another Yorkshire beach coral.

Nice colour but some detail lost due to recrystalisation.

 

coral_image_6e.jpg 

 

Corallites to 18mm.

 

 

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Reply with quote  #277 

 

Hi Tarquin,

that's a super Lithostrotian Vorticale, I love those myself.

 

Another Yorkshire beach coral.

 

coral_image32c.jpg 

 

Corallites to 4mm.

 

 

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Reply with quote  #278 
Hi Roy,
Lovely preservation on that Actinocyathus (Lonsdaleia) floriformis, I think it's overall the most beautiful Carboniferous species.

I believe the last one is Siphonodendron pauciradiale.





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Reply with quote  #279 




 

Hi Tarquin,

thanks again for the ID.

I think all the Carboniferous corals are beautiful, much more appealing than the Jurrassic corals which also occur commonly on the same Yorkshire beaches.

 

coral_image_9c.jpg 

 

This is quite a nice one.

Very hard to spot as a sea worn pebble and usually poorly preserved.

 

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Reply with quote  #280 


I wouldn't say no to that! - I guess it's Isastraea sp. though I don't know much about Jurassic corals.

I've been looking for Orionastraea (Carb.) which superficially looks similar (i.e. no coral walls) but would expect it to be similarly invisible as a beach pebble!

Actually, my rarest coral from the N. Yorks coast is probably this early Lias Heterastraea, almost unknown from the area:

As found:
IMG_1834_-_Copy_1a.JPG 

After prepping with KOH:
IMG_1849_-_Copy_1.JPG 




Edited by TqB 2013-04-29 19:39:56

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Reply with quote  #281 
 

Hi Tarquin,

thanks again for the ID, I am not yet confident enough to put a name on any of them and your help is much appreciated.

 

That Heterastraea is superb, I don't expect it would have remained in that condition for long with the tumbling action of the North Sea. It has really prepped well with the caustic. Well done!

 

I have seen pictures of the Carboniferous Orionastraea but never found one either.

 

Another Yorkshire beach coral.

 

coral_image23c.jpg 

 

Corallites to 10mm.

 

 

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Reply with quote  #282 

That's another fine L. vorticale. There seems to be a source bed somewhere that produces these beautifully coloured specimens, I wonder if it's been located.

Ed: What was I thinking? - pretty sure that's an Actinocyathus...
Edited by TqB 2013-03-02 21:06:14

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Reply with quote  #283 
A couple of Michelinia specimens from Morecambe Bay, Arundian stage, Dalton Formation.

A small complete corallum that just dropped out of a shale bed:
IMG_1988_copy_-_Copy.jpg 
IMG_1989_-_Copy_1.JPG 

Part of a much larger corallum in limestone, found loose covered in mud on the "beach".
Polished section shows the many tabulae.
IMG_1990_-_Copy_a.JPG 



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Reply with quote  #284 

Michelinia section:
IMG_2173_-_Copy_1.jpg 
IMG_2174_-_Copy.jpg 




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Reply with quote  #285 

 

Hi Tarquin,

Michelina is one I've not heard of before, thanks for showing it.

 

The Yorkshire coast is the only location I have experience of collecting coral fossils from and it is good to see specimens from other sites.

 

Another one.

 

coral_image35c.JPG 

 

Corallites to 10mm, nice colour but just starting to crystalise.

 

 

 

 

 

 

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Reply with quote  #286 
This thread continues to amaze, keep it up!
Thanks
Dave

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Reply with quote  #287 
 

Anther Yorkshire beach coral.

 

coral_image42c.jpg 

 

Corallites to 10mm, again starting to crystallise but still interesting.

 

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Reply with quote  #288 

 

Another Yorkshire beach pebble.

 

coral_image43b.jpg 

 

Pebble size approx 62mm by 51mm.

Shame about the cracking, but still quite nice.

 

 

 

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Reply with quote  #289 
Hi Roy,

That last one is a classic Palaeosmilia murchisoni - I've only found one erratic Yorkshire coast pebble of it but have a few whole ones from elsewhere.

It often loses its epitheca (outer wall) before fossilisation so appears rather ghostly - here's my pebble, outer layers are pyritised (1cm scale):
IMG_1930_-_Copy.JPG a
IMG_1929_-_Copy.JPG 
IMG_1929_-_Copy_2.JPG 



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Reply with quote  #290 
 

Hi Tarquin,

thanks again for the ID, it's good to see your specimen as a comparison. I expect you will need to keep an eye on that pyrite in case of pyrite rot.

 

Bit of a whopper this time from the Yorkshire coast.

 

coral_image44a.jpg 

 

Coral size approx 72mm by 54mm.

 

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Reply with quote  #291 


Thanks for the advice. 1500 seems a lot for the odd cut here and there.
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Reply with quote  #292 

 

Hi Keen Steve,

don't give up on the polishing, you can get good results with wet and dry abrasive paper.

 

Another Yorkshire coast coral pebble.

 

coral_image36c.jpg 

 

Pebble approx 60mm.

Not the best detail, but I like the bold cell walls.

 

 

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Reply with quote  #293 
 

Another Yorkshire beach coral.

 

coral_image46e.jpg 

 

Pebble 86mm by 56mm, a common coral and a nice example.

 

 

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Reply with quote  #294 
Hi Roy,

That impressive large solitary a couple of posts back has got me flummoxed:
Too few septa for Palaeosmilia
Septa too long for Caninia, and axial structure wrong
Could be a large Dibunophyllum bipartitum craigeanum - axial structure fits but again don't know if there are enough septa...





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Reply with quote  #295 
Hydrangea - That  last  one was  is  brilliant  -  love  it. 
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Hi Tarquin,

tricky things to ID sometimes aren't they!

I realise my corals are of little geological value as their exact origin can never be determined. I collect them simply because I like them and I don't worry too much about the ID although it is nice to know.

 

Hi Danny1,

thanks for the compliment. Keep watching as I have a real beauty coming soon!

 

coral_image_7d.jpg 

 

Corallites to 8mm, again Yorkshire coast.

 

 

 

 

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Reply with quote  #297 
 

Starting to run out of showy pieces to show now, but lots of less colourful ones if you want to see them.

Here's what I think is a real beauty.

 

coral_image_4c.jpg 

 

coral_image48a.jpg 

 

Size of pebble 86mm by 58mm.

 

 

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Reply with quote  #298 
That is an unusually attractive one, Diphyphyllum, probably fasciculatum. 


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Reply with quote  #299 
Beautiful, i only wish i had some equally nice pieces to contribute, unfortunately my measely Crag specimens arent lookers.
Thanks
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Reply with quote  #300 
 

Thanks Tarquin and Dave.

 

Another Yorkshire beach pebble.

 

coral_image50b.jpg 

 

Size approx 102mm by 52mm.

 

coral_image50a.JPG 

 

 

 

 

 

 

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