Simon Wellings
@metageologist.bsky.social
I write about Geology:
https://all-geo.org/metageologist/ and Front Vision magazine.
I've published papers on gabbros and the havoc they wreak: https://scholar.google.com/citations?user=8pJUbAoAAAAJ&hl=en
https://all-geo.org/metageologist/ and Front Vision magazine.
I've published papers on gabbros and the havoc they wreak: https://scholar.google.com/citations?user=8pJUbAoAAAAJ&hl=en
Lighting like this is necessary to make the features visible, but whenever I see images of Ediacaran fossils my first reaction is to think they are images from a vampire film.
March 28, 2025 at 2:37 PM
Lighting like this is necessary to make the features visible, but whenever I see images of Ediacaran fossils my first reaction is to think they are images from a vampire film.
Wow. This includes even one of my (quote obscure) scientific papers. Still behind a paywall and copyright the Royal Irish Academy
March 20, 2025 at 1:57 PM
Wow. This includes even one of my (quote obscure) scientific papers. Still behind a paywall and copyright the Royal Irish Academy
Enjoying the frenzied limestone at Augsburg station, noisy with tropical life. Plenty of fossils and blotchy with bioturbation.
Each grain is the product of life and probably passed through the guts of, or been picked over by multiple critters subsequently
⚒️
Each grain is the product of life and probably passed through the guts of, or been picked over by multiple critters subsequently
⚒️
February 16, 2025 at 3:35 PM
Enjoying the frenzied limestone at Augsburg station, noisy with tropical life. Plenty of fossils and blotchy with bioturbation.
Each grain is the product of life and probably passed through the guts of, or been picked over by multiple critters subsequently
⚒️
Each grain is the product of life and probably passed through the guts of, or been picked over by multiple critters subsequently
⚒️
You'll remember the cutting through the chalk then - quite spectacular in its way.
January 31, 2025 at 3:00 PM
You'll remember the cutting through the chalk then - quite spectacular in its way.
Then the sinuous etched land of the Chilterns. The product of slow dissection of a huge slab of chalk. Frozen but not scoured by the Ice Ages. Some of these valleys have no streams.
January 31, 2025 at 2:20 PM
Then the sinuous etched land of the Chilterns. The product of slow dissection of a huge slab of chalk. Frozen but not scoured by the Ice Ages. Some of these valleys have no streams.
Revelling in the lidar DTM layer in the National library of Scotland website and the varied types of British landscapes it unveils.
First we have glacially shaped land in the Vale of Eden looking like the skin of a dinosaur.
⚒️
First we have glacially shaped land in the Vale of Eden looking like the skin of a dinosaur.
⚒️
January 31, 2025 at 2:20 PM
Revelling in the lidar DTM layer in the National library of Scotland website and the varied types of British landscapes it unveils.
First we have glacially shaped land in the Vale of Eden looking like the skin of a dinosaur.
⚒️
First we have glacially shaped land in the Vale of Eden looking like the skin of a dinosaur.
⚒️
Top quality views, right now.
January 2, 2025 at 12:04 PM
Top quality views, right now.
This sea wall is made of shelly limestone blocks.
One fossil caught my eye. Any ideas what it might be?
One fossil caught my eye. Any ideas what it might be?
December 15, 2024 at 2:25 PM
This sea wall is made of shelly limestone blocks.
One fossil caught my eye. Any ideas what it might be?
One fossil caught my eye. Any ideas what it might be?
Maybe needs a generic word for boundary - here's a tree that ate a wall in the West Country.
www.somersetcountygazette.co.uk/news/1548825...
www.somersetcountygazette.co.uk/news/1548825...
December 13, 2024 at 11:15 AM
Maybe needs a generic word for boundary - here's a tree that ate a wall in the West Country.
www.somersetcountygazette.co.uk/news/1548825...
www.somersetcountygazette.co.uk/news/1548825...
Folded Moine sediments, shores of Loch nan Uamh, Arisaig #Scotland.
Note how the feldspar grains (white blebs) are aligned horizontally, parallel with the 'axial plane' of the fold.
#FridayFold
⚒️🧪
Note how the feldspar grains (white blebs) are aligned horizontally, parallel with the 'axial plane' of the fold.
#FridayFold
⚒️🧪
December 13, 2024 at 10:43 AM
Folded Moine sediments, shores of Loch nan Uamh, Arisaig #Scotland.
Note how the feldspar grains (white blebs) are aligned horizontally, parallel with the 'axial plane' of the fold.
#FridayFold
⚒️🧪
Note how the feldspar grains (white blebs) are aligned horizontally, parallel with the 'axial plane' of the fold.
#FridayFold
⚒️🧪
Billion year old sandstones, folded like a stack of towels, the layers picked out by some visiting wildlife.
'Moine' rocks, Arisaig peninsula, Scotland.
#fridayFold ⚒️
'Moine' rocks, Arisaig peninsula, Scotland.
#fridayFold ⚒️
November 29, 2024 at 7:50 AM
Billion year old sandstones, folded like a stack of towels, the layers picked out by some visiting wildlife.
'Moine' rocks, Arisaig peninsula, Scotland.
#fridayFold ⚒️
'Moine' rocks, Arisaig peninsula, Scotland.
#fridayFold ⚒️
Boulders of red sandstone, scattered by vanished ice. Suilven, the mountain they came from, looks on like a mother hen.
There are so many, contrasting with the grey bedrock, that the hill is called Fàire nan Clach Ruadha or 'look-out of the red rocks'.
⚒️ #scotland
all-geo.org/metageologis...
There are so many, contrasting with the grey bedrock, that the hill is called Fàire nan Clach Ruadha or 'look-out of the red rocks'.
⚒️ #scotland
all-geo.org/metageologis...
November 28, 2024 at 11:57 AM
Boulders of red sandstone, scattered by vanished ice. Suilven, the mountain they came from, looks on like a mother hen.
There are so many, contrasting with the grey bedrock, that the hill is called Fàire nan Clach Ruadha or 'look-out of the red rocks'.
⚒️ #scotland
all-geo.org/metageologis...
There are so many, contrasting with the grey bedrock, that the hill is called Fàire nan Clach Ruadha or 'look-out of the red rocks'.
⚒️ #scotland
all-geo.org/metageologis...
Achmelvich beach, North of Lochinver, Scotland
November 28, 2024 at 7:35 AM
Achmelvich beach, North of Lochinver, Scotland
This covers the area that my favourite folded rock comes from (see previous tweets). There are some wonderful diagrams in it.
November 27, 2024 at 9:48 AM
This covers the area that my favourite folded rock comes from (see previous tweets). There are some wonderful diagrams in it.
To me, this ornament in my office looks quite like a quartz crystal.
Is this deliberate, or simply inevitable once they'd decided the base was a hexagon?
Perhaps there are only so many shapes with hexagonal symmetry.
Is this deliberate, or simply inevitable once they'd decided the base was a hexagon?
Perhaps there are only so many shapes with hexagonal symmetry.
November 26, 2024 at 4:07 PM
To me, this ornament in my office looks quite like a quartz crystal.
Is this deliberate, or simply inevitable once they'd decided the base was a hexagon?
Perhaps there are only so many shapes with hexagonal symmetry.
Is this deliberate, or simply inevitable once they'd decided the base was a hexagon?
Perhaps there are only so many shapes with hexagonal symmetry.
Metamorphism is what turns drab basalt into Christmassy reds and greens. It tells us what goes on inside subduction zones, in mountains and other hidden places.
I've written many explainers on the topic.
Overview:
all-geo.org/metageologis...
Or start at the beginning:
all-geo.org/metageologis...
I've written many explainers on the topic.
Overview:
all-geo.org/metageologis...
Or start at the beginning:
all-geo.org/metageologis...
November 24, 2024 at 11:57 AM
Metamorphism is what turns drab basalt into Christmassy reds and greens. It tells us what goes on inside subduction zones, in mountains and other hidden places.
I've written many explainers on the topic.
Overview:
all-geo.org/metageologis...
Or start at the beginning:
all-geo.org/metageologis...
I've written many explainers on the topic.
Overview:
all-geo.org/metageologis...
Or start at the beginning:
all-geo.org/metageologis...
A fold that you can hold.
Granite vein within a migmatitic gneiss, Scotland.
Heat muddy sediments to c. 700 deg. C and they start to melt. New granite magma fills cracks, leaving behind darker mica/Garnet areas. Hot rocks are squishy - a straight crack becomes wiggly.
#fridayFold ⚒️
Granite vein within a migmatitic gneiss, Scotland.
Heat muddy sediments to c. 700 deg. C and they start to melt. New granite magma fills cracks, leaving behind darker mica/Garnet areas. Hot rocks are squishy - a straight crack becomes wiggly.
#fridayFold ⚒️
November 22, 2024 at 11:18 AM
A fold that you can hold.
Granite vein within a migmatitic gneiss, Scotland.
Heat muddy sediments to c. 700 deg. C and they start to melt. New granite magma fills cracks, leaving behind darker mica/Garnet areas. Hot rocks are squishy - a straight crack becomes wiggly.
#fridayFold ⚒️
Granite vein within a migmatitic gneiss, Scotland.
Heat muddy sediments to c. 700 deg. C and they start to melt. New granite magma fills cracks, leaving behind darker mica/Garnet areas. Hot rocks are squishy - a straight crack becomes wiggly.
#fridayFold ⚒️
A pair of images from deformed igneous rocks, Currywongaun, Connemara, Ireland. One normal, other with 'crossed polars'
Large amphibole grains on left surrounded by smaller sheared-out grains. Mylonitic quartz/opaque fabric on right obscured by later grain growth/annealing.
#thinSectionThursday ⚒️
Large amphibole grains on left surrounded by smaller sheared-out grains. Mylonitic quartz/opaque fabric on right obscured by later grain growth/annealing.
#thinSectionThursday ⚒️
November 21, 2024 at 7:39 AM
A pair of images from deformed igneous rocks, Currywongaun, Connemara, Ireland. One normal, other with 'crossed polars'
Large amphibole grains on left surrounded by smaller sheared-out grains. Mylonitic quartz/opaque fabric on right obscured by later grain growth/annealing.
#thinSectionThursday ⚒️
Large amphibole grains on left surrounded by smaller sheared-out grains. Mylonitic quartz/opaque fabric on right obscured by later grain growth/annealing.
#thinSectionThursday ⚒️
Highly recommend this if you want to invest in a detailed book on the #Geology of Scotland. ⚒️🧪
Much changed since previous editions and now fully up to date.
New chapters on the history of geology, geoconversation, & energy transition.
Much changed since previous editions and now fully up to date.
New chapters on the history of geology, geoconversation, & energy transition.
November 17, 2024 at 2:28 PM
Highly recommend this if you want to invest in a detailed book on the #Geology of Scotland. ⚒️🧪
Much changed since previous editions and now fully up to date.
New chapters on the history of geology, geoconversation, & energy transition.
Much changed since previous editions and now fully up to date.
New chapters on the history of geology, geoconversation, & energy transition.
Finally, metamorphism. Nothing much here - 300 deg. C maybe, but enough to cause new minerals to grow. More visible on the back is a layer of feldspar that grew probably due to the action of hot fluids. A thin-section would tell me more, but to damage such a lovely thing, never!
November 15, 2024 at 12:36 PM
Finally, metamorphism. Nothing much here - 300 deg. C maybe, but enough to cause new minerals to grow. More visible on the back is a layer of feldspar that grew probably due to the action of hot fluids. A thin-section would tell me more, but to damage such a lovely thing, never!
The ~ shape folding is late. But traces of the earliest stretching and folding remain. Tiny detached folded quartz layers probably formed as the layers slid past each other. Or just maybe they show that the top and the bottom are the same layer, folded like dough in the heart of a mountain.
November 15, 2024 at 12:36 PM
The ~ shape folding is late. But traces of the earliest stretching and folding remain. Tiny detached folded quartz layers probably formed as the layers slid past each other. Or just maybe they show that the top and the bottom are the same layer, folded like dough in the heart of a mountain.
Secondly these rocks have been folded multiple times forming mountain-scale squid-shaped loops.
Think of a croissant. Early stretching and folding forms the flaky layers as flat parallel folds, the main shapes are made from folding them again. Do this to hot rocks and you can make mountains.
Think of a croissant. Early stretching and folding forms the flaky layers as flat parallel folds, the main shapes are made from folding them again. Do this to hot rocks and you can make mountains.
November 15, 2024 at 12:36 PM
Secondly these rocks have been folded multiple times forming mountain-scale squid-shaped loops.
Think of a croissant. Early stretching and folding forms the flaky layers as flat parallel folds, the main shapes are made from folding them again. Do this to hot rocks and you can make mountains.
Think of a croissant. Early stretching and folding forms the flaky layers as flat parallel folds, the main shapes are made from folding them again. Do this to hot rocks and you can make mountains.
Firstly, they were never flat. The picture shows how complex sedimentary rocks can get in shallow-marine / tidal places. Mud and sand is mixed together and what were ripples or channels on the sea-bed become lumps and bumps in cross-section. My sample started out the same, 750 million years ago.
November 15, 2024 at 12:36 PM
Firstly, they were never flat. The picture shows how complex sedimentary rocks can get in shallow-marine / tidal places. Mud and sand is mixed together and what were ripples or channels on the sea-bed become lumps and bumps in cross-section. My sample started out the same, 750 million years ago.
The peach-coloured layers are mostly quartz, the darker mostly mica. This colour-pallette is what makes it attractive, but the shapes are the interesting part. There is an obvious broad ~ fold but look carefully and the layers are arrayed in complex ways; they intermingle, form loops, buckles. Why?
November 15, 2024 at 12:36 PM
The peach-coloured layers are mostly quartz, the darker mostly mica. This colour-pallette is what makes it attractive, but the shapes are the interesting part. There is an obvious broad ~ fold but look carefully and the layers are arrayed in complex ways; they intermingle, form loops, buckles. Why?
The sad job of clearing out my childhood home is offset by the joy of finding many of my old rock samples.
This beauty is from the Mamores, mid-way between Ben Nevis and Glencoe, Scotland. It’s a piece of folded “Dalradian” metamorphic rock and has inspired me to write a #FridayFold ⚒️ thread…
This beauty is from the Mamores, mid-way between Ben Nevis and Glencoe, Scotland. It’s a piece of folded “Dalradian” metamorphic rock and has inspired me to write a #FridayFold ⚒️ thread…
November 15, 2024 at 12:36 PM
The sad job of clearing out my childhood home is offset by the joy of finding many of my old rock samples.
This beauty is from the Mamores, mid-way between Ben Nevis and Glencoe, Scotland. It’s a piece of folded “Dalradian” metamorphic rock and has inspired me to write a #FridayFold ⚒️ thread…
This beauty is from the Mamores, mid-way between Ben Nevis and Glencoe, Scotland. It’s a piece of folded “Dalradian” metamorphic rock and has inspired me to write a #FridayFold ⚒️ thread…