Pleistocene Gravels?

[Neovenator12]

Always keeping an eye out for potential Pleistocene stuff I spotted this large slippage of flints and orange sediments at the Lower Chalk cliffs near Ventnor on the Isle Of Wight whilst looking for Ammo's and Sharks teeth etc. I was wondering whether anyone could possibly identify if this is a slippage of river gravels or not. Any help would be really appreciated.

[Kosmoceras]

Hi,

Can you take some more pictures of the area? It reminds me of a dissolution pipe. In the chalk you can find small to large pipelines filled with young quaternary sediments. These are called dissolution pipes and were formed when rainwater percolates through overlying quaternary sediments and increase in acidity dissolving the underlying chalk in channels as gravity acts on it along natural weaknesses. These fill with the young sediments and gravels to form a brown to orangey appearance and often filled with flints. Dissolution pipes normally start off with a fairly wide channel and gradually thin out as you proceed down into deeper layers averaging out as funnel shaped.

Regards,

[Neovenator12]

Thank you for the very quick reply, will do my best to get the photos, although you may have to wait a week or so as I go down there once every 2 weeks. Sorry about that.

[Neovenator12]

Thank you for the very quick reply, will do my best to get the photos, although you may have to wait a week or so as I go down there once every 2 weeks. Sorry about that.

Completely ignore that post, I managed to get down there and have just returned. I've done a 'Pleisto-scout' of the whole area:

A band of gravels above the slip, I think this could be the source though i'm not sure.

The cliffs around the area.

The slip

Some of the flints.

The sediments (Orangey soils)

A thick band of gravels at the top of the cliff 75m away.

Hope this can help. The colour of the sediments reminds me like you said of a dissolution pipe or of the Pleistocene gravels at Brook bay etc.

[Kosmoceras]

Hi, thanks for the images. I don't think these are river gravels due to the nature of the flint, if it was tumbled in a river I would expect it to be more rounded but these look quite rough. Pleistocene though, I would not be able to tell.

Regards,

[Neovenator12]

Ok, thank you for your help

[Jersey]

It may be an area of very weathered limestone which releases the more resistant flint. If there is a geologic map available of the area (perhaps on the internet) you can check what the rock formation is in that area. I agree with Kosmoceras that the flint gravels do not have the appearance of having been tumbled in a river since they are not rounded.

Edited June 23, 2013 by Jersey