Cwm Idwal

Posted 5 December 2011 by

Photograph by Michael Roberts. Photography contest, Honorable Mention.
Cwm Idwal, a hanging valley in North Wales. Mr. Roberts adds, "Darwin's favourite place. This is looking down into Cwm Idwal in Snowdonia, which Darwin visited several times in the 1820s and in August 1831 just before he received the invite for the Beagle and in 1842 when he was studying glaciation. "In 1831 Darwin studied the rocks, which are mostly Ordovician volcanics, but was a bit confused by them. He was on his own and wrote to Sedgwick for advice. In 1842 (halfway through writing his first draft on "his Theory") he returned and found clear evidence of glaciation. To the right of the lake (Llyn Idwal) was an ice fall which Darwin called a vomitory. The dark cliffs on the left are Ordovician volcanics, which he thought were basalt." You may find Mr. Roberts's article on Darwin's fieldwork here, but you will not find it cheaply..

7 Comments

apokryltaros · 6 December 2011

This valley is so lovely, they (re)named an osteostracan after it, Cwmaspis (Cephalaspis) billcrofti

Matt Bright · 7 December 2011

Beautiful. I used to go there a lot and yomp up the odd mountain – one of the loveliest landscapes in the world. Snowdown may be impressive, but Tryfan and/or the Gwydrs are more of a workout and give cracking landscape – the latter, in particular, is like the surface of another planet.

bigdakine · 7 December 2011

Beautiful photo. But more vowels please.

Paul Burnett · 7 December 2011

- bigdakine said: Beautiful photo. But more vowels please.
Whattaya mean? It's got two! "Cwm" is pronounced "coom" (Anglicized to "coombe"). It's an original "W" - a "double U" - so it's really spelled and pronounced "cuum".

Michael R · 7 December 2011

Thank you I am most honoured

This was taken in August 2007 while leading a trip for Harvard led by Andrew Berry. By the lake the weather was awful, but Andrew and I saw some blue sky so went over the tops - the Glyderau 1000metres to Plas y Brenin where Darwin stayed

For more see C:\newdarwin)\Geological Society - Rocks of ages.mht on Darwin's 1842 glacial visit . You will see the boulders and the headwall of the cwm above the lake is where I took the photo

Michael R · 8 December 2011

More names

This was taken part way between Gyder Fawr and castell y Gwynt above Cwm Cneifion to the right is Pen yr Oleu Wen and beyond that carnedd Dafydd. The valley is Nant Francon and the island is Ynys Mon

Welsh names are fun

Michael R · 20 December 2011

Peter

Did you only post to advertise

I have not dumped my brain