The Geologic Oddity in Australia where the Mantle is Exposed; Macquarie Island
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- čas přidán 7. 07. 2024
- In a section of Australia, the mantle is being actively exposed on the surface at this very moment. And no, I am not referring to a volcanic eruption. Rather, I am referring to Macquarie island, which hosts a colorful assortment of primarily green minerals which include olivine (whose gem form is known as peridot), serpentine, and zoisite. This video will explain how a piece of the Earth's mantle ended up above sea level.
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Google Earth imagery used in this video: ©Google & Data Providers
Thumbnail Photo Credit: Photo Credit: Derivative of an image (resized, cropped, + other modifications) from (Kimberley Collins, Flickr, CC BY 2.0), and is used & licensed under CC BY 2.0 by / geologyhub
Creative Commons Licenses used for specific content (such as a single image within the video which as a whole does not entirely fall under the same license) or sections of specific content (such as a photo within a table) in this video (not the entire table for this example):
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Sources:
[1] Rosalind M. Coggon, Damon A.H. Teagle, Michelle Harris, Garry J. Davidson, Jeffrey C. Alt, Timothy S. Brewer,
Hydrothermal contributions to global biogeochemical cycles: Insights from the Macquarie Island ophiolite,
Lithos, Volume 264, 2016, Pages 329-347, ISSN 0024-4937, doi.org/10.1016/j.lithos.2016..., CC BY 4.0
Note: This was used to source the minerals mentioned in the video's description.
[2] Crameri, F., Magni, V., Domeier, M. et al. A transdisciplinary and community-driven database to unravel subduction zone initiation. Nat Commun 11, 3750 (2020). doi.org/10.1038/s41467-020-17..., CC BY 4.0
[3] Dominic A. Hodgson, Alastair G.C. Graham, Stephen J. Roberts, Michael J. Bentley, Colm Ó Cofaigh, Elie Verleyen, Wim Vyverman, Vincent Jomelli, Vincent Favier, Daniel Brunstein, Deborah Verfaillie, Eric A. Colhoun, Krystyna M. Saunders, Patricia M. Selkirk, Andrew Mackintosh, David W. Hedding, Werner Nel, Kevin Hall, Matt S. McGlone, Nathalie Van der Putten, William A. Dickens, James A. Smith, Terrestrial and submarine evidence for the extent and timing of the Last Glacial Maximum and the onset of deglaciation on the maritime-Antarctic and sub-Antarctic islands, Quaternary Science Reviews, Volume 100, 2014, Pages 137-158, ISSN 0277-3791, doi.org/10.1016/j.quascirev.2.... (www.sciencedirect.com/science..., CC BY 3.0
Creative Commons Image Sources:
Penguins:
www.flickr.com/photos/1147061...
Sepentinite:
www.flickr.com/photos/jsjgeol...
Dunite:
www.flickr.com/photos/jsjgeol...
Serpentine w/ chromite:
www.flickr.com/photos/jsjgeol...
0:00 Rocks from the Mantle
0:36 Macquarie Island
1:44 A Disclaimer
2:18 Plate Tectonics
2:30 Macquarie Island Hypothesis
4:06 Conclusion
The reason I created my own model is because all of the papers I read were using overly broad details to describe their hypothesis. In other words, the authors of those papers weren't sure either.
3
Super awesome. I live in the southern San luis valley in Colorado. Could you possibly do a video on the geography of the area as well as the types of minerals and rocks you could find? I adore geology and love your channel so much!
@@maryssalynnemedley8871 I might be able to do this.
@@GeologyHub You could do like the now-numerous plant identifying CZcamsrs and walk around with your phone in one hand recording your other hand picking up all the rocks and talking about what they are. That would be awesome.
It's a bit dismaying that even when we can observe exhumation of upper mantle occurring, we still can't figure out exactly how it's happening.
I wonder if this is typically how ophiolites are built -- spreading ridge (generates your pillow basalts) --> transform fault --> transition to very oblique, half-ass subduction because of crust of similar density on either side of the boubdary?
Huh, maybe when continental crust approaches this sort of a weak subduction trench, the direction of subduction could switch? I guess that would be an opportunity for the ophiolite block to get scraped off on a continental margin.
Weird stuff.
"This is my own hypothesis and may be proven wrong in the future."
We need more of this kind of honesty in the world today. Thank you.
mRNA clot shots, cough
@@DigitalDissident oh cool what conponent of the nucleic acid can cause that. I wanna hear from you
Climate change, cough…
@@KK-pq6lu Is a real and present danger.
@@DigitalDissident What does that have to do with geology?
There's a another impressive mantle exposure in Australia, The Redbank Thrust Zone that cuts just outside the town of Alice Springs. At he north side of the thrust, the Moho was displaced upwards locally by 25-30 km (some say 40km) vertically until the mantle itself was literally lifted above the earth's surface. It's an inland area with minimal vegetation, so the spectacular shear zone itself and mantle rocks are all exposed directly to human eyes. I will definitely find a time to visit it myself.
Those are incredibly old though. This is a much more modern phenomenon.
I cant handle the mantle being with us on the cusp of our crust.
"Thrust Zone"
heh
Interesting. Thanks 😊
Ophiolites have always been a fascinating subject. Partly because they are uncommon and nobody ever gave a decent explanation (at least in the early '80s when I was getting my BS Geo...) for their origins. Great video!
They don't seem that uncommon to me, living on the N. American West Coast as I do. We have ophiolites in the Northern Sierra Nevada and Klamath Mountains of California and Oregon, and ophiolites in the North Cascades of Washington. And ophiolites in SW British Columbia, and Alaska I think.
*_*edit*_*
And ophiolites in the Blue Mountains of eastern Oregon.
The first time I saw serpentinite was around 1970 in a roadside outcrop in southwestern Oregon. I didn’t know yet what it was (I believe the term “ophiolite” wasn’t officially defined until a couple of years later), but it sure looked neat to me.
Living in the Pacific Northwest near the Can-US border, I realized just how interesting our area is. We have a large dunnite, a lot of serpentinites up to nephrite, ophiolites and many of the associated minerals. All of these can pretty easily be seen in a day. Thank you for an interesting video.
The Pacific Northwest is really geologically complex. Almost anything you’d care to study is within a few hours.
Nick Zentner has many videos on ophiolites in Washington.
There is large area of extruded mantle in Gros Morne National Park in western Newfoundland, Canada as well. It is called the tablelands, and is virtually barren. Nothing grows on it. It is a geologic wonder, easily accessible to tourists and is popular with hikers.
yep, spent two summers there in the late 80's working on my M.S. Incredibly beautiful place.
I visited once years ago, just for a few hours... and it was amazing... never to be forgotten! Everyone should go to Newfoundland...
Yup😀‼️It’s a piece of mantle from 30 klms deep thrust up onto the surface when the Iapetus Ocean closed up during the formation of Pangea. The tablelands in Gros Morne are barren and devoid of plant life because the mantle has a certain type of mineral rock that only forms deep in the mantle and also inhibits plant growth. That island, I noticed, is also quite barren.
sounds like a plausible hypothesis. thank you for sharing this beautiful island.
My high school geology class took a field trip to a local ophiolite (: NW of Seattle, WA. the Fidalgo ophiolite
OH man, my heart skipped a beat when I read the title of this! I never imagined part of the mantle would be on the surface!
I've learned about serpentinite from geology professor Nick Zentner (Central Washington Univ); apparently a lot is found in Central and Eastern WA. He said how it's created on the seafloor, indicating how much of Washington state (most of it, actually) is built from exotic terranes.
For future reference, Macquarie is pronounced "Ma-Quarry". I grew up in Port Macquarie. Both were named after a Govenor of NSW, Lachlan Macquarie.
Love the vids. Cheers.
The comment I was planning to write also! Macquarie is closer to ‘mc wurry’ than to ‘mc warry’.
@@spiralpython1989 well the people who live in and near Port Mackwarry might disagree with you there old mate!
@charles Neeson
I'm not sure ' horizontally' is correct either,,? More like 'laterally',,🤔
I mean he says besific for 'specific' at 4:07 but long mineral names are fine :p
I think that's what he said? "Ma-Quarry" is how I would write the pronunciation given in the video.
I was out in my backyard rolling some ophiolites around and then came inside and bunged on You Tube for a breather and the first thing that come up was Macquarie Island/mantle ophiolites. Here in Tasmania we have the best Ultra Mafic suites (Pre Cambrian mantle outcrops) in Australia. Bar none. They include every secondary mineral generally associated with them, including black and white jade, nephrite, osmiridium, platinum, stichtite, chromium, magnetite, actinolite, pyrhotite, crocoite, pentlantite, nickel, axinite etc. etc. It sure beats having to take the tinny out for a run down to Macquarie to flog some mantle scraps. Regards to you for your excellent hub. Please keep them coming. Rory, Tasmania.
Tinnie to Macquarie Island lol.
I really like Macquarie island and wish more people knew about it, it’s really interesting, and I wish to visit it
I read about it ages ago from a book about it
But perhaps it’s better that way as historically, people knowing about it wasn’t good
(Sad for the wildlife that went extinct, hope we get a way to revive them in the future)
There's been a very successful pest eradication project removing cats, rats, and rabbits. While some non-migratory animals have become extinct, we're seeing a very healthy return of both flora and fauna (given the circumstances).
It's that one piece of my home state that I doubt I will EVER get to visit. Though, the closest would be the special Macquarie Island flora house at the Hobart Botanic Gardens which at least houses a good few species from the island. I find the island quite captivating, both in its brutal, rugged beauty, and in the more scientific wonders of the place.
Thank you. One small point: Macquarie is pronounced mack (or sometimes the Scottish "Mc") - quarry.
It (like a lot of places in Australia) is named after Governor Lachlan Macquarie. (en.wikipedia.org/wiki/Lachlan_Macquarie)
In his book on Australia Bill Bryson makes fun of how that governor used his office to put his name on as many things as possible. “We have found a wee new island in need of a name.”
I grew up on Staten Island, NY. There are large serpentine deposits there, and when you drive on the Staten Island Expressway, you can see the green serpentine cliffs where they cut through hills and exposed the bedrock.
Super awesome. I live in the southern San luis valley in Colorado. Could you possibly do a video on the geography of the area as well as the types of minerals and rocks you could find? I adore geology and love your channel so much!
Oh cool! I was just out in crestone last weekend, place is amazing, hiked north crestone and the geology is insane.
The honesty and integrity you show in your explanations is missing from much of the science today.
Fascinating! Thank you from England. Every video you is full of easily understood information.
appreciate the honesty and transparency
North of Macquarie Island, the Puysegur Trench is said by scientists studying it to be the world's newest subduction zone. It apparently is a suduction zone that is just being born. The Solander Islands (last known eruption ~20,000-50,000 years ago) may be the first volcano to come from this subduction zone. Geologists who study the topic of Suduction Initiation (how subduction zones are born) are starting to study the Puysegur Trench.
Hey, I’m very interested in the Kaikoura earthquake and the resultant uplift from it, Im wondering if we would see more of these types of earthquakes in the future and how such a big uplift occured. Thanks!
Dont worry you might see a nuclear war before the next big earth quake lol
Please do a video on Gros Morne National Park, Newfoundland where there are massive exposures of mantle rock.
I came here to also request this. I've been to the Tablelands at Gros Morne NP, and it's such a spectacular landscape!
Great Vid GH, fascinating stuff. I really dug this video, mantle on the surface is new to me.
If you get bored or want something different to do check out the chalk rocks in western kansas or the Flint hills of Eastern Kansas. I'm sure most people don't even know they exist or that the flint hills are so massive. Aquifers would be a cool topic as well.
Entertaining and educational at the same time. This is why I enjoy your vids!
I think I was recommended this video because I am in an Earthquake science class this semester and my professor has a lot of youtube resources. This was really interesting though, thank you for making the video.
Thanks so much for covering such an interesting location.
Thank you for your work!
Fascinating! Thanks for the video. 😊
Other places where this can be seen are near Popondetta in Papua New Guinea's Northern Province; Troodos Massif in Cyprus, The Lizard Peninsular in Cornwall and an area along the Oman coast near Muscat. I've seen the PNG and British ones.
Excellent and informative video. Thanks Geo.
Very nicely presented and interesting information. Thank you
Thanks! My first look at the island!
I find it equally interesting that this is the only place on the planet where a collision of oceanic plates lead to uplift. Zealandia and its associated formations are full of surprises! New Caledonia also has a fascinating geologic history.
Only current place we know it has happened before. This process known as obduction was particularly much more common back in Earth's deep past. the best example is probably up in Newfoundland where an entire oceanic slab including the Moho discontinuity are exposed to the surface. Its also notable for the Avalon biota which preserves abyssal ecology of the Ediacaran biota. Frankly I'm a bit surprised to learn this kind of process is still going on as I had thought of it as something that generally happened deep in Earth's ancient past i.e. Archean and has become far less common as plate tectonics became more efficient with time driven by the cooling of the mantle increasing the fraction of mineral hydrates mantle rock can support.
@@Dragrath1 I knew about Newfoundland's Ediacaran biota, and the long range fault, but not about the entire oceanic slab! An exposed Moho seems amazing to visit. Eastern Canada is a geologic wonderland, I really ought to go some day...
I would've figured that earlier Earth would have had even less of a chance of obduction but I guess the potential for many more small, hot oceanic microplates, and as you mentioned less mineral hydrates makes a lot of sense. If I recall correctly mountain building events may have acted very differently in the deep past due to less biological activity lubricating oceanic plates with carbon. Earth a billion years ago must've had absolutely alien geology.
That seems plausible to me. Thanks very much for all your info.
I absolutely love science and I love geography, thanks for bringing the two together. 😊
This is geology, not geography!
Very interesting. Thank you for sharing.
Tks for another interesting vid. I'd be interested in seeing a segment on the impact site in north west Sask, Canada. The parallel finger lakes sort of indicate the edges.
Another fantastic video ! Thank you 😊
How good of you to begin by explaining that how this island formed remains somewhat of a mystery! So much of our planet is constantly evolving and new discoveries are being made all the time which change preconceived ideas and adjust accepted ideas. I have some Serpentine, from Tasmania, comes for a locale not too far from me, so do we have some exposure in Tassie, too? Thanks for this expose!
Wow this is really cool.
I'm a physicist but I love geology.
One of my favorite professors in undergrad was a geophysicist.
I wish I knew more about geology!
That's pretty cool. I've never heard of this place.
what make that area so interesting is the subduction zones just above and below.
near new Zealand south island the Australian plate is being subducted beneath the pacific plate.
south of the Macquarie island it looks like the pacific plate is going under the Australian plate.
I heard the fault beneath Anak Krakatoa is in a similar situation
Thank you. I find geology fascinating, and have enjoyed your videos for a long time. I rarely comment, but just wanted to say thanks 😊.
Amazingly interesting. Thank you.
Excellent! Don't be afraid to speculate. Put ideas out there and see what arguments are made for and against. That's what science is supposed to be about. Personally, the more arm waving the better.
Fascinating, thank you!
Great vid !!!
Fantastic! I love this!
This Macquarie Island is a great story. Thanks very much.
Now that would be my idea of a vacation, going to that island with enough time to just look about. Imagine walking on the damned mantle. Just totally nerding out on this video, many thanks.
I've come across xenoliths like that as inclusions in rocks high up on the slopes of Maunakea. They're pretty neat looking!
Thank you did not know that and I loved your explanation!
Very cool! Reverse subduction zone!
So cool!!!
Great theory!
Love your channel! Can you do a video on Starved Rock in IL? Thank you, keep up the great work!
Holy crap that was about the most information-dense 4 mins I've ever experienced.
Thanks a lot for your work. I miss none of them!
I am glad that you greatly enjoy my content :)
Thanks for the excellent presentation. It’s a fascinating place, with many intriguing rock formations. I’ve spent nearly two years there in three visits, and experienced several large earthquakes on the island - magnitude 8.4, 7.4 and 6.8.
Eek. That's gotta be a real shaky place.
Really interesting, thank you.
Excellent - would be interesting to see more on minerals. Another would be on the kimberlite pipes in Arkansas.
The Hidaka Mountains in Hokkaido formed the same way. And are also full of the same minerals.
Its the same tectonic setting...
23rd of january in 1973 there was that famous eruption in the Westman Islands in Iceland. Next 23rd of january you should publish a cool video about that eruption on the 50th anniversary. ;)
Very nice :) & awesome vid :D
Very good , thesis material.
I wish I had a yacht because I'd love to visit that island...
This is super cool!
that sepentine is known as stichtite-serpentine.. we get the same stuff here in tasmania
Fascinating!!
nailed it. nice job 🙂
The rock at :55 looks like it has rubies in the serpentinite matrix.
Great video! Thank you for sharing your hypothesis sir, I find it convincing!
Garnet is quite common, probably that.
Exposed mantal can also be seen in Newfoundland and Iceland.
In most.of Newfie, top soils and clays are only a few inches deep before you hit solid rock.
If ever touring the province you'll see small garden patches along the road, these are a product of the clearing when the road was being.made. the top.spil scraped to the side, making a favorable patch to grow a few vegetables. Each patch belongs to the adjacent land owner with an unspoken rule (exceptmtp brag for the rare tourist passing thru lol) that no one ever touches a garden not belonging to them. It's pretty cool.
Fascinating.
You should do a video about the exposed mantle in gross morne national park in Newfoundland, canada.
Apparently we have mantle exposure in SW Colorado off Hwy 3 before you get to the intersection of 3 and 550/160
I have a piece of the mantle from an exposed section in Norway, Garnet-Lherzolite, it's very fascinating and also slightly gratifying holding a beautiful complex rock made of our very own mantle! It's rare for our surface rocks but miles underneath it's everywhere! Can you imagine what the largest crystal structure on Earth might look like?
Concise. Nice
*oh?!* that’s super cool!!! I can’t wait to see some :)
Very interesting presentation, thanks for the work you did. I'm interested because I live on an ophiolite landscape on the small island of Fidalgo, in Puget Sound in Washington State, USA. We see serpentinite here, but certainly no wonderful crystals like the ones you showed. The evidence seems to say that our little patch of rocks originated in the Western Pacific below the equator. It's a bit of lower-level oceanic crust that got scraped off onto the continental crust of the NA plate. Sometimes the stuff Nature comes up with defies belief!
Love the geologic oddities
And in Cornwall in the UK too... Coverack Beach.
Those rugged edges on the island remind me of the Kamchatka Peninsula with how they both look like serrated saw blades
Really enjoy the variety of the topics you research. On top of the numerous requests you no doubt receive, is there a chance you can do a video on the formation of the area of Toyama, Japan. It would be information that would be helpful to my students. Located on the Eastern side of Honshu the main island of Japan. Interesting points are a large deep bay, halfway surrounded by an isthmus, the alluvial floodplains which is now the city, backed by the "Japanese Alps", a youngish mountain range. Not sure you can get that specific, if you can't then the formation of the Japan Sea would be great....which would actually be the formation of Japan.
There’s a serpentine grassland near Baltimore called Soldiers Delight.
I think I speak for everyone when I say that you should release one longer length video each week! it seems you have much more to say about each topic that you need to cut out in order to shorten the video down. I'd love to hear what your hours of research have discovered!
Interesting theory :)
Can you make a video about the Gardnos crater.? Its very interesting because you can actually see the bedrock in a river that flows through it, and its one of the world's most accessible meteorite craters.
I can think of several locations: Shetland Islands, Oman, Cyprus, Portlethen outside Aberdeen.
Fascinating video thanks! Those are some very odd rocks. In case anyone cares (and it certainly doesn’t really matter), pronunciation of Macquarie doesn’t rhyme with ‘Mary’, but rather is the same as “quarry”: Mc + quarry. Wikipedia cites MacQuarrie as “an Anglicisation of the Gaelic Mac Guaire, which was a patronymic form of the Gaelic personal name meaning ‘proud’ or ‘noble’”, and it is apparently wholly unrelated to the Irish ‘Maguire’, which derives from Uidhir / Odhar, meaning “dun / dark’.
Thank you!
This seems very plausible. How else would mantle material be thrust up above the Earth's surface? And no evidence of volcanoes and their associated magma chambers? Perhaps the antithesis of a subduction zone. Such a rare and fascinating place. Imagine rock hunting there.
@GeologyHub -- what an interesting spot on our planet! Slipping and subducting -- why not? Macquarie Is. would be an interesting place to explore, but the weather is probably miserable. Sydney is much more inviting.
Have you done a video on the 8th Continent of Zealandia? I'd like to understand more about this theory with respect to its location in today's world. Thanks, as always.
That last rock was amazing...
May be a clue in that in Raglan NZ we have a similar set of deep mantle rocks exposed in the Alexandra volcanic zone of which many strange samples are taken.
I love the peridot gems......
A video on the optimal geological conditions that and produce gold and platinum please.
I don't know if this question is really your area of expertise, but could you give a talk on how pallasites are formed?
Slow cooling mantle rocks produce many striking minerals. Most are very mafic, quite different than crustal rocks in that you don't see much quartz or feldspar. You also don't see much amphibole either, as the rocks solidified in anhydrous conditions.
I’m wondering if the exposed mantle in Newfoundland is still rising. Could you comment on that?
My theory is its more literally a section of mantle cut off,
the fault expanded to a point but then was crushed closed, this bit of mantle at the line was somehow shoved on top of one plate which piled up into the island shape
I would be interested in your presentation on the derivation of the serpentine of southern Oregon, U.S.A.
Can you make a video about highly active Kliuchevskaya group of volcanoes? Just several very active volcanoes sitting in a very close proximity. Do they share a one giant magma chamber, and is it a begining of a new supervolcano?
Nice! But would have liked to see more of the mantle-borne minerals.