Fascinating. I have walked and scrambled there many a time and it was helpful to have you explain the geology. I have never been to Blaeneau Ffestiniog when it wasn't raining. Amazing place. Thanks!
Hello Rob, my knowledge of slate was restricted to schoolboy facts backed up by many visits to Llanberis and Blaenau. I am surprised and delighted to come across your channel (now subscribed) with a proper explanation of these rugged Welsh landscapes which continue to fascinate and intrigue me. Many thanks for uploading!
Perfect view of the 'Indian Face' of Tryfan in profile at about 7.56min mark behind Rob. Rotate your screen 90° anticlockwise, and you will see the Indian and his headress. Spent many weeks at Og. Cott. as a youth, never studied the geolgy of the area properly, we just wanted to climb or kayak! Thanks for this insight.
Just about to go up to Eryri for a fortnight's holiday. Very happy to find your video now. I shall look out for the distorted green reduction spots and the ignimbrite fiamme. Intrigued to read more about the Cambrian/Ordovician palaeogeographical context now!
You've been caught out by language differences at places such as 8:08. Tryfan is not pronounced 'Triffan' with an accented first syllable. It's more like 'Truvaan', with the emphasis on the second syllable. In Welsh, the 'f' is an English 'v'. The letter 'ff' is pronounced like an English 'f'. (And yes, there are a number of Welsh alphabetical letters which are made up of two Latin letters. They are pronounced differently to single letters. These include ch, dd, ff, ll, rh and th. And, once you understand how the alphabet works, the pronunciation is usually exactly according to the spelling.
Additionally 'y' is pronounced more like 'uh'. It really makes a difference and is appreciated if you try to pronounce Welsh words correctly. Just ask a local if you don't know how. People who visit regularly and pronounce Pen-y-Pass as 'Penny pass' get my goat!
As a rock climber I'm familiar with all these places. However, I'm also an engineer and educator, and always on the lookout for ways of visualising strain in three dimensions (usually in metals and other engineering materials). This, especially the ovoid iron formations, have given me a great new example to use. Thanks.
@@robbutler2095 The bit I don't get is that the fracture plane in the slate seems to be the plain which has experienced the most compression. Am I right, and if so, can you refer me to an explanation? As you will realise, I'm not a geologist.
@@derekryden6574 Sure. The "fracture plane" - which makes the slate a great building material - is "cleavage"... formed by aligned, flattened mineral grains - so it isn't a fracture (in the tensile sense). The platey minerals - like pieces of paper - form this this alignment in the same orientation given by the shape of the reduction spot (=strain ellipsoid). This is the strain ellipsoid's (in geo-notion) X-Y plane (where X is long and Y the intermediate length axes of the ellipsoid), and then of course has the minimum length axis (Z) as its pole - the direction of maximum compression. Hope that helps...
I spent 8 weeks in 1975 as a conservation volunteer building stone walls on the track below the Devil's Kitchen. Staying on Willy's farm (Gwern Gof Isaf?). One of the hardest times of my life.
I’ve learned more about geology in this one video than I have reading multiple books! To be able to visualise the Dykes and the faults is fascinating. And especially poignant given what is happening near grindavik at the moment in Iceland.
Glad to be of use. There are a bunch of things elsewhere on The shear Zone channel that might be of interest. Not go too far into igneous geology - but there are some in the maps section and in tectonics.
Indeed - it is amazing - but in the modern World not unusual. For example, beneath the South Caspian Sea there is over 20km thickness of sediment - of which 10km was deposited in the past5 million years. Probably quite a good modern analogue for a future slate belt....
very interesting and informative Rob, do you know anything about the first hydro power station being a cover for a human hybrid cloning military program? , could be a good idea for a video .
Apologies for creating some confusion -many of my films are made for students or amateur geologists... if you've a specific piece of jargon you'd like covering - let me know...
Thank you for explaining the geology of the area so clearly in such poor wet weather.
Thanks - it was a bit damp....
@@robbutler2095It usually rains in Snowdonia!
Thank you so much for posting this, I live in Llanberis and look at Dinorwig Quarry every day but I’ve learnt so much from this video. Thanks again.
thanks - glad you found it useful!
I’ve lived in the. Land of slate and the weather was wet a lot. And misty. But very beautiful when it was a hot day. Thanks for sharing.
Fascinating. I have walked and scrambled there many a time and it was helpful to have you explain the geology. I have never been to Blaeneau Ffestiniog when it wasn't raining. Amazing place. Thanks!
Thanks - yes - great rocks and its nice when the sun shines (unlike on the vid)...
fascinating stuff and very well presented. great post, thank you.
Hello Rob, my knowledge of slate was restricted to schoolboy facts backed up by many visits to Llanberis and Blaenau.
I am surprised and delighted to come across your channel (now subscribed) with a proper explanation of these rugged Welsh landscapes which continue to fascinate and intrigue me.
Many thanks for uploading!
thanks - glad you're enjoying these films!
Superb Rob... Took me back to 1976 and many times since. Great that you used your original mapping field sketches... xxx :-)
Perfect view of the 'Indian Face' of Tryfan in profile at about 7.56min mark behind Rob. Rotate your screen 90° anticlockwise, and you will see the Indian and his headress. Spent many weeks at Og. Cott. as a youth, never studied the geolgy of the area properly, we just wanted to climb or kayak! Thanks for this insight.
9:39
Wow. That was really interesting. Thank you so much for the detailed information.
Thanks for a fascinating background to one of my favourite places on earth. In weather that's not my favourite but is all too typical!
Thanks from Spain!
Llanberis astonished me when I got there. Good museum and narrow gauge railway!
Just about to go up to Eryri for a fortnight's holiday. Very happy to find your video now. I shall look out for the distorted green reduction spots and the ignimbrite fiamme.
Intrigued to read more about the Cambrian/Ordovician palaeogeographical context now!
Very informative field video about deformation by penetrative strain. Thank you Prof. Rob.
Glad you found it useful - it's a classic area!
I used to live in a miner’s cottage outside Bethesda. Xx
Diolch for this video! Very interesting! Diolch for using the new/original name for Eryri also :)
Amazing......Thanks for the info, I would have never imagined such a density possible.
You've been caught out by language differences at places such as 8:08. Tryfan is not pronounced 'Triffan' with an accented first syllable. It's more like 'Truvaan', with the emphasis on the second syllable. In Welsh, the 'f' is an English 'v'. The letter 'ff' is pronounced like an English 'f'. (And yes, there are a number of Welsh alphabetical letters which are made up of two Latin letters. They are pronounced differently to single letters. These include ch, dd, ff, ll, rh and th. And, once you understand how the alphabet works, the pronunciation is usually exactly according to the spelling.
Additionally 'y' is pronounced more like 'uh'. It really makes a difference and is appreciated if you try to pronounce Welsh words correctly. Just ask a local if you don't know how. People who visit regularly and pronounce Pen-y-Pass as 'Penny pass' get my goat!
Interesting, thank you. 😊
As a rock climber I'm familiar with all these places. However, I'm also an engineer and educator, and always on the lookout for ways of visualising strain in three dimensions (usually in metals and other engineering materials). This, especially the ovoid iron formations, have given me a great new example to use. Thanks.
Great - glad this stuff is useful. The reduction spots in slates were important for developing understanding of 3D strain in geology....
@@robbutler2095 The bit I don't get is that the fracture plane in the slate seems to be the plain which has experienced the most compression. Am I right, and if so, can you refer me to an explanation? As you will realise, I'm not a geologist.
@@derekryden6574 Sure. The "fracture plane" - which makes the slate a great building material - is "cleavage"... formed by aligned, flattened mineral grains - so it isn't a fracture (in the tensile sense). The platey minerals - like pieces of paper - form this this alignment in the same orientation given by the shape of the reduction spot (=strain ellipsoid). This is the strain ellipsoid's (in geo-notion) X-Y plane (where X is long and Y the intermediate length axes of the ellipsoid), and then of course has the minimum length axis (Z) as its pole - the direction of maximum compression. Hope that helps...
@@robbutler2095 Thanks, that's really helpful.
Enjoyed your video. Very interesting, great explanation. Glad you popped up. Would love to visit there and see it for myself.
Thanks - lots more to be found on the channel...
I spent 8 weeks in 1975 as a conservation volunteer building stone walls on the track below the Devil's Kitchen. Staying on Willy's farm (Gwern Gof Isaf?). One of the hardest times of my life.
I’ve learned more about geology in this one video than I have reading multiple books! To be able to visualise the Dykes and the faults is fascinating. And especially poignant given what is happening near grindavik at the moment in Iceland.
Glad to be of use. There are a bunch of things elsewhere on The shear Zone channel that might be of interest. Not go too far into igneous geology - but there are some in the maps section and in tectonics.
I had a friend that lived there,his cottage was built with a boulder of slate in the wall
It boggles me to imagine how much sedimentation is able to acumulate on an ocean floor so thickly layer upon layer to form such huge deep structures.
Indeed - it is amazing - but in the modern World not unusual. For example, beneath the South Caspian Sea there is over 20km thickness of sediment - of which 10km was deposited in the past5 million years. Probably quite a good modern analogue for a future slate belt....
❤❤
I may have had a rum.... But I've never before noticed the high correlation between geological language and inuendo. 😳 3:30 and 4:46
very interesting and informative Rob, do you know anything about the first hydro power station being a cover for a human hybrid cloning military program? , could be a good idea for a video .
not really in scope of this Channel!
@@robbutler2095 that's exactly what your'e supposed to say if you are part of the cover up rob, we know what your really up to....
Some explanation of the jargon would have been useful.
Apologies for creating some confusion -many of my films are made for students or amateur geologists... if you've a specific piece of jargon you'd like covering - let me know...
Any Lithium or failing that Sodium, in amongst that lot!?
in slates?
Great but it's a shame you don't call it by it's Welsh name: llechi 😐
ITS STILL SNOWDONIA .!!!!!!!!