GuidesMagazineShopBuy FossilsJoin Hunts
Char Le Mar
Hi,  

Going through our rock collection we rediscovered this.  I remember that I picked it up  because it reminded me of a animal paw print. I know it's probably not but not sure enough to relegate it to the rockery yet.  

As ever,  haven't a clue where  we found it.  I have a bad memory! 
Any ideas? 

Thanks, 

Charlotte

IMG_20200524_135120.jpg  IMG_20200524_135212.jpg
Quote 0 0
Barrow Museum
Charlotte,
I was rather hoping that someone else would answer this, as I'm not an expert, but have a notion of what it might be.  First, though, you have not indicated the scale (a ruler alongside would have been useful) and I should like to see the cross section as well as the bedding plane view.

I can say it is not an animal footprint - so you were spot-on there. It a not a fossil or tgrace fossil, either.  But that doesn't diminish its interest as a geological object.  I do believe that you have quite a good example of soft sediment deformation structures.  These are formed when layers of unconsolidated sediment move relative to each other, before hardening into rock.  The movement can be due to differences of pore pressure in one layer relative to another.  For example, a heavier mud over a waterlogged sand might  induce de-watering of the sand which then "bursts" upwards in blobs into the finer-grained mud.  The movement can be triggered by shock, such as an earthquake.  There are many different styles of deformation structure, and a classification which I won't go into here and now, though I suspect yours would be classed as "load structures".  But from what I can just see of the structures on the sides of the block, my interpretation may not be incompatible.
Quote 0 0
Char Le Mar

Hi Barrow  Museum, 

Sorry,  rookie errorr re the scale!!  Have included pics with scale and better side view.  Thanks for your explanation.  The rock will now add a little interest to the herb garden. 😀

IMG_20200526_171236.jpg  IMG_20200526_171335.jpg 
Quote 0 0
Dirty Pete
That last pic looks very much like chert and I think I see 'bands'.....which puts it in the mysterious realm of replacement by silica / chemical precipitation etc..etc..
Could it have been from a Chalk area?

Pete.
Quote 0 0
Gary W
Last photo is definately a piece of flint (which is chert) looks like it is beach worn.
Gary
Quote 0 0
Barrow Museum

Now I can see the side, I agree with Pete and Gary, that it resembles chert.  How those strange features on the top/base came about, I wouldn't like to guess without close inspection.  I suppose it is still possible that some soft sediment movement brought about the features you can see, but I am also in agreement that a good use would be to enhance your herb garden!  As for the host formation...Chalk may be a possibility, particularly if it is from the Northern UK Province, but I would favour the Upper Greensand of the general Dorset coast area, where the banding would be commoner.  In truth, it could have been picked up almost anywhere.

Quote 0 0
Char Le Mar
Actually,  Dorset is a strong contender for where we may have picked it up. Really going to have label things in future!  Thanks for your comments and interest.  

Charlotte
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