GuidesMagazineShopBuy FossilsJoin Hunts
lawnmower



here is one of mine found on the Yorkshire coast
 
[attach:fileid=uploads/1233/DSC05625_Correction.JPG]
 
a close up
 
[attach:fileid=uploads/1233/DSC05626_Correction.JPG]
Quote 0 0
Bugg
hi guys, was just wondering, while fossiling i often bring a sept nodule home to have cut n polished if it shows promise but have never found any fossil remains in them, some great crystal formations but no fossils, yet in walmsleys guide to the whitby area he says that many of the sept nodules contain marine reptile remains, anyone found anything in them apart from crystals ? all mine are just full of calcite etc  

Quote 0 0
fossil mad

Bugg,


heres the end of a small septarian nodule with bone in it.

 

[attach:fileid=uploads/640/bone__1.jpg]

 

[attach:fileid=http://www.discussfossils.com/forum/uploads/640/bone__2.jpg]

 

Adrian & keeley
"When can we go fossil hunting again?"
Quote 0 0
Mioplax
By pure definition Septarian concretion or nodules only rarely include fossils. Septarian concrecions form around mineral water seaping through mud and have sevaral cracks and beautifull minerals, Calcite, Barite, Sodium etc... inside, but rarely fossils, and if then only poorly preserved.

"Septarian concretions or septarian nodules, are concretions containing angular cavities or cracks, which are called "septaria". The word comes from the Latin word septum; "partition", and refers to the cracks/separations in this kind of rock. Septaria usually contain crystals precipitated from circulating solutions, usually of calcite. Siderite or pyrite coatings are also occasionally observed on the wall of the cavities present in the septaria, giving rise respectively to a panoply of bright reddish and golden colors. Some septaria may also contain small calcite stalagtites and well-shaped millimetric pyrite single crystals."

450px-Septarian_Nodule.jpg 
Fossil bearing concretions are formed around a living (dead) organism, as a result of decay proceses, and although they look similar on outside, have very little comon with septarian nodules.
Quote 0 0
P King Chef
That's pretty Mioplax.

Looks almost like a piece of Aztec wall art.


Pete

At work I have to make a lot of sacrifices.
It's one of the benefits of being a Druid.
Quote 0 0
rockhopper

Here's another one showing n fossil remains, sadly not mine.  I offered a ƒâ€š‚£10 for it but he told me to............

septarian-nodule.jpg 
Quote 0 0
Bugg
some nice pieces there guys, that bone in the nodule looks really interesting adrian n keeley, but its not the kind of nodule that i class as a sept, the other 2 are like the kind i find, i think maybe walmsley was mistaken when he said about reptile remains in sept nodules, although ive seen big nodules that i would say arent septs but have cracks running through them that have slightly crystalised, maybe its the sheer size that leads to them cracking through shrinkage etc when forming then crystalises, just a thought im prob wrong :)   
Quote 0 0
spider
Very interesting to see these sectioned, Quite beautiful Thumbs Up
Have a nice day :0)
Quote 0 0
Bugg
they can be quite spectacular spider, its just the luck of the cut, costs me ƒâ€š‚£7.50 for every slice but you just can never really tell what it will turn out like, think i need to start looking at building my own slab saw :/ 
Quote 0 0
spider
I suppose ƒâ€š‚£7.50 is a bit steep Im sure you can get them done cheaper than that, what size do you find them usually?. I would very much like to see some of the specimens you have found :o)
Have a nice day :0)
Quote 0 0
Bugg
i find them from maybe 8 in across upto 3ft, needless to say the 3ft ones stay where they are lol, i thought ƒâ€š‚£7.50 was steep to but its the only stonemasons round here so im stuck i guess, will take some pics and upload some spider, just had one cut that had yellow/green tinge to the calcite but it was a bit dissapointing to be honest, but at ƒâ€š‚£7.50 a go im loathe to have more of the nodule sliced, deff need a slab saw, sept nodule slices seem very popular in the states      

Quote 0 0
Al B
Here is a Sepatarian Nodule  with a couple of fossil in it!  I had it prepped a couple of years ago.
 

Vert_prepped_1.jpg 

 

The main problem with septarian nodules is that as they dry out they can eventually crack along the crystals and fall to bits.  This one has had a couple of tubs of superglue just to hold it together.

 

So far it has outlived the phone at least!
Quote 0 0
dinogary
al b  what are the bones from??
Growing old is compulsory, Growing up is optional!
Quote 0 0
mudbug2
Alan
 Nice bones, any ideas what this from ?? Where did you collect it etc...

 

Regards to all who share the passion Mudbug...

 
S.H.T-N
Quote 0 0
Al B
Plesiosaur Vertebra, Cryptoclidus, mid Jurassic, Oxford clay.
 

P King Chef remembers them!
Quote 0 0
rocktapper
Alan,well done with the bones - quite rare tooSmile.
 

Looking at your photo those septs dont look too bad.

 

The marine reptile blocks in Yorkshire have septs in them anything up to 25mm  thickCry.

 

Still get some good stuff in them thoughThumbs Up.

 

Cheers

  Mark
Quote 0 0
P King Chef

Al B wrote:
!  I had it prepped a couple of years ago.
 
 


Still looking good though Al.
I know you were a bit dubious as to how long it would hold together.
Pete

At work I have to make a lot of sacrifices.
It's one of the benefits of being a Druid.
Quote 0 0
Al B
Hi Pete
 

The main reason it is "still looking good", is that that phote is from a couple of years ago!!!

 

Nevertheless, yes, in life it looks much the same.  I guess keeping humidity and temperature constant are important - and not dropping it!!
Quote 0 0
heath

Hi Bugg

Its a while since you posted septarian nodule stuff (11 April )  I do like them and the local Dorset, Kimmeridge Clay ones are fascinating mysterious objects,rsz_septarian_nodule_ammos_005.jpg  but I never found any fossils in them, UNTIL NOW!!!

Here's a photo of an ammo (Rasenid), but it's more on the surface than inside nodule

all the best, good hunting              Heath


Quote 0 0
ryanc
Im not seeing a septarian nodule in that pic - just looks like a sedimentary nodule to me?
 

Regards,

 

Ryan
Quote 0 0
heath

Hi Ryan

Defo septarian nodule! When split they are full of crystals.  I forgot the scale-  nodule c.2ft and the ammo c.1ft diameter (a macroconch)  They are far too heavy for me to lug home, so I just photograph any fossils, and there are several septaria at present with ammos on them at this site 

all the best Heath

Quote 0 0
spider
Bug, You never did post any photo's of your cut nodules. I been looking forward to them.
Have a nice day :0)
Quote 0 0
Richard
Hi Heath

I think Ryan is correct - this does not look like a septarian nodule.

My dictionary defines it as  ' a large roughly spheroidal concretion.........characterized by a network of radiating and intersecting mineral filled cracks'
Richard
Quote 0 0
Bugg
hey spider i did say i would didnt i, have been working away but will do it this weekend, will have to take some new pics as old lappy is dead  

Quote 0 0
heath

Hi all, Its good when your questions spur me to check up on facts, helps to improve and sharpen the old brain!!

Here's a new septarian nodule picrsz_septarian_nodule_ammos_003.jpg 

As you see there are 2 kinds, brown, more irregular shaped and full of a crazy paving of crystal filled fragments, and the type of my first post, ie  the grey cushion type and 1 broken piece to show the calcite filled interior.

The ammo fossils are on the exterior surface (not in this photo though)

I looked up my source  Arkell "Geology of....Weymouth, Swanage, Corfe and Lulworth" 1968 reprint

He definitely calls  these structures septarian nodules. SO unless there is a more up-to-date definition these are septaria!!  Further along the foreshore are another type, still round, grey, but like a pad of bulbs which are stuck together with calcite, and fall apart very easily.

Do enlighten me if I've got it wrong!!!        Heath

Quote 0 0
ryanc
Here's a really big septarian nodule - one of the moeraki boulders from New Zealand.


 - you can see the prominent septa on the surface - these are formed as cracks as the initial lump of clay/mud dry's out and is later infilled by another mineral (usually calcite).

 

The other more standard nodule has the same composition of calcite and mud/clay but the calcite infils normal cracks from weathering,stress etc. so the pattern of cracks is different.

 

The complicating factor is that unworn septarian nodules might not exhibit the septa until you break them but you cant conclusively say if it is or is not without seeing the septa.

 

Both are very similar in composition though so probably a bit mixed up in the literature.

 

Regards,

 

Ryan
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