Cotswold rock formation

[WhiskyBottle]

Hello
Never visited this forum before. I was told this rock flow was something special and a particularly good example, but I can't remember what it was. Can anyone help.

It's in Midger Wood in the South Cotswolds. A spring keeps water flowing over these rocks. The green colour is stained I believe, possilbe algae. The streem behind me (Kilcot Brook) also has shelves of this green sttained rock.



Thanks

[The Woodman]

I believe this rock is called "Tufa". The dissolved calcium carbonate (limestone) in the spring water deposits on the substrate - whatever that may be. Algae, moss, leaves, twigs can be covered and over time mass accretions are formed.

Similar formations can be found on the overhanging banks of the River Kent south of Kendal. Moss growing on limestone gets covered with the deposited calcium carbonate and retains the structure of the moss. More moss then grows on that and the mass of Tufa forms. Any object if left will be "petrified". Big lumps sometimes fall into the river when they cannot self support.

This phenomenon occurs in several other places, notably Mother Shiptons Cave near Knarsborough, Yorks. where all sorts of objects are hung on strings in the dripping water. Hats, teddies and shoes are just some of them.

[ChrisJB]

There are excellent layered tufa deposits at the waterfalls at Gordale Scar and Janet's Foss, near Malham, as well.

Regards, Chris

[WhiskyBottle]

Tufa - that's what I was trying to remember. Thanks Folks.

It is a Limestone area. I'll have to have a closer look next time. It's rather crumbly and there's lots of loose pieces.

[sunnydale]

I know of a lovely cottage that's made of Tufa. It's called 'Tufa Cottage' (can't think why!).
I'll post a pic of it when I get chance. It's a charming looking place.