Teddy Tours - Thorns Gill

[QDanT]

judging by the way this is orientated i would say this is an erratic.
if it is the same rock however then i'm not entirely sure - could be the same rock type from a different locality.
however if you look at the way it has been weathered you can see that the two rocks are slightly different. - the upper (erratic) rock has obvious bedding planes and is quite smooth, while the rock it is rested on is quite angular and fractured.
andy

The way I read it, and am no Geologist, an erratic is a different rock type moved and deposited somewhere else onto a different rock type.
Where as here it's the same rock type i.e. Limestone but the top one has come from somewhere else and has been rounded and shaped by the ice then when the ice melted was left on the ground protecting the ground under neath it while all the surrounding ground is eroded away by wind and in the case of Limestone by acid rain leaving the deposited boulder on a pedestal.
To quote from a few tours back "Erratics-R-Us" They certainly give a focus to go out on a mission to find them and "have a brew" and as I research locations and go to find them I find more and more local places I've never been ----------------------cheers Danny

 

[Everything Mac]

The way I read it, and am no Geologist, an erratic is a different rock type moved and deposited somewhere else onto a different rock type.
Where as here it's the same rock type i.e. Limestone but the top one has come from somewhere else and has been rounded and shaped by the ice then when the ice melted was left on the ground protecting the ground under neath it while all the surrounding ground is eroded away by wind and in the case of Limestone by acid rain leaving the deposited boulder on a pedestal.
To quote from a few tours back "Erratics-R-Us" They certainly give a focus to go out on a mission to find them and "have a brew" and as I research locations and go to find them I find more and more local places I've never been ----------------------cheers Danny

you are quite correct Danny - an erratic is a rock deposited somewhere other than where it was formed - usually by a glacier but it could be any number of processes.

the erosion you mention is actually quite common as the upper rock protects the lower rock.

i am curious as to why there are vertical fractures in the lower rock though. - it may well have been tilted in some way.


any way - cracking pics mate.

atb
andy

 

[EdS]

both local limestone but laid down at different periods so (slightly) different conditions - simply put Yoredale Series over laying Great Scar Limestone.

I'm a bit rusty on Dales geology (cave stuff is ok though) as the NY Moors was my thesis area. But the bottom blocky layer is precipitation limestone whilt the upper block is coral and fossil stuff.

 

[QDanT]

What a mine of information BCUK is, thanks for that Eds
cheers Danny