The chemical uniformity of Earth’s mantle is greater than previously believed.
Lavas from hotspots—whether erupting in Hawaii, Samoa, or Iceland—likely originate from a worldwide, uniform reservoir in Earth’s mantle, according to an evaluation of volcanic hotspots recently published in the journal Nature Geoscience.
The findings suggest that Earth’s mantle is much more chemically uniform than previously believed, with lavas gaining their unique chemical “flavors” only as they journey toward the surface.
Surprising Findings on Mantle Homogeneity
“The discovery literally turns our view of hotspot lavas and the mantle upside down,” said Dr. Matthijs Smit, associate professor and Canada Research Chair at the University of British Columbia’s Department of Earth, Ocean and Atmospheric Sciences. “In a way, Earth’s lavas are much like humankind itself—a beautifully diverse population with a common ancestor, which developed differently wherever it went.”
Research of Earth’s mantle has been complicated by the fact that it can’t be sampled directly. Scientists instead have to engage in a bit of geoscientific detective work; they study this important part of our planet through trace-element and isotope analysis of lava that comes from the mantle and is erupted at oceanic volcanoes around the world.
The vast differences in composition of these lavas, along with the assumption that the isotope composition of magma doesn’t change between its source and the surface, has led to the general view that the mantle contains distinct reservoirs of different age, located in different regions, and formed by different processes. The observations made by Dr. Smit and co-author Dr. Kooijman of the Swedish Museum of Natural History’s Department of Geosciences indicate that the reality may be quite different.
New Insights into Magma Pathways
“By looking at a specific set of elements, we were able discern the chemical effects of various processes that act on magma melts on their way to the surface to discover that all hotspot lavas actually share the same starting composition,” said Dr. Smit. “The lavas only come out differently because the magmas interact with different types of rocks as they ascend.”
Earth’s mantle is a seething layer of molten and semi-molten material comprising about 84 per cent of the planet’s volume, which lies between the iron core and the surface crust. When magma derived from the mantle penetrates the crust and erupts onto the surface it is called lava.
Knowing what the mantle is made of is central to our understanding of how our planet formed and how the mantle has developed over time. It may also provide clues as to why the mantle behaves the way it does, how it drives plate tectonics, and what its role is in the global cycle of elements.
Besides shedding entirely new light on hotspot lavas in oceanic parts of the world, the analysis also revealed an exciting new link to basaltic lavas on the continents. These melts, which contain diamond-bearing kimberlites, are fundamentally different from magmas found at oceanic hotspots. They nevertheless prove to have the same magma “ancestor”.
“The discovery is a game-changer when it comes to models for Earth’s chemical evolution and how we look at global element cycles,” said Dr. Smit. “Not only is the mantle much more homogeneous than previously thought, it likely also no longer contains “primordial reservoirs”—entities that were once needed to explain the data, but could never really be reconciled with the concept of mantle convection.”
“This model explains the observations in a simple way and permits a myriad of new hypotheses for global geochemical research going forward,” said Dr. Kooijman.
Reference: “A common precursor for global hotspot lavas” by Matthijs A. Smit, and Ellen Kooijman, 19 September 2024, Nature Geoscience.
DOI: 10.1038/s41561-024-01538-7
Financial support for this research was provided by the National Science and Engineering Research Council of Canada.
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14 Comments
I’m not a geological expert nor am I even a well versed scientist.
I understand the the nature of an ever changing evolution world….but what I really would like to know is how much of the under ground and above ground explosions of man made nuclear testing has changed the normality
Of our earth/ home. ?
At least my understanding that scientists are, in fact, one clueless bunch of charlatans hasn’t been shattered and it never will be.
Ah yes there’s always one of you that thinks the discovery of a new variable is a “gotcha” moment for your case against the objective observations of science. Being contrarian just for the sake of it doesn’t make you smart.
Science isn’t some cryptic thing being kept from you that you’re meant to accept but a collection of small repeatable, verifiable, objective observations used to paint a larger picture, sometimes some variables are knowingly missing and some inferences are made to create a model until more data is obtained, these inferences are by definition made using evidence, if models change based off more observations this is merely progress. This same methodology leads to fundamental understandings used to make the phone you’re using work and the million other things you see and use everyday that’s taken for granted
Sure the individual scientist is subject to their own ego or bias but the very nature of science weeds this out through peer review and said objective observation available to anyone that looks.
On the other hand your denial of it has no such filter, the attempted refutation of science is only held up by small human emotions seeking to validate whatever belief it is you feel is threatened by science. Science is not subject to the whims and wishes of mere humans and will continue to progress each day with new observations while all you’ll have is the same circular argument and rhetoric pulled from your own flimsy ego
Peer review doesn’t always work. There are also studied that are skewed on bias because of funding they get.
Ah, so you’re one of those who think that verbosity is a sign of intelligence. You’ve misread me, because of course you have, and dumped way too much bollocks for me to unpack, so I’ll try to be brief.
I’m not objecting to science. If I were, I wouldn’t be here, obviously. But I am objecting to scientists as a group, because of the stark contrast between the extremely elevated status scientists have in today’s society – particularly among scientifically illiterate sycophants like yourself – and the tiny amount of actual useful output they produce. And that includes the phone I’m using. So, as a group, with few notable exceptions, they’re just a bunch of clueless charlatans. Am I making myself clear now?
And if you knew anything about how mundane and shallow peer reviewing process actually is most of the time, you’d shut up about peer reviews. And objectivity. There’s no objectivity in science.
Yes…misinformation is the norm. Chemical ls don’t and can’t evolve into life. It is a disproven MYTH that they “can” or “did”.
The most sophisticated and complex and voluminous code ever assembled did not do so accidentally…as people naively BELIEVE.
I am interested to read and interprete such geoscience related discoveries. But I have a quetion on how the plate techtonic, earh quake and volcanic eruption changes the composition of the mantle, or they do not affect at all. Also what will be our earth after millions of years? Can we/humans prolong tbe process?
Yes…misinformation is the norm. Chemical ls don’t and can’t evolve into life. It is a disproven MYTH that they “can” or “did”.
The most sophisticated and complex and voluminous code ever assembled did not do so accidentally…as people naively BELIEVE.
Yes…misinformation is the norm. Chemicals don’t and can’t evolve into life. It is a disproven MYTH that they ever “can” or “did”.
The most incredibly sophisticated and most complex and most voluminous code ever assembled did not do so accidentally…as people naively BELIEVE.
i know something not quite right when things take too long to cool down.
Hello Jeannie I have been asking that question for quite a while. If you know about quantum theory man made nuclear energy could have a detrimental effect on the natural cycle on earth’s rotation and weather patterns. Personally I don’t agree with them playing with certain toys.
Presuppositions of evolution do not account for what happened to initiate these processes. No one has ever observed a single evolutionary event. No one has created something from nothing.
We can not observe the past, just shad I ws, which ate not facts on and of themselves. Creation science pre supposes these same natural processes but, are under the creator’s control..speeding up or slowing down in accord with God’s will.
“Turns Our Understanding Upside Down” – New Discovery Shatters Old Models of Earth’s Chemical Evolution
And yet, and yet. . . the science on the arguably even more complex subject of climate change is “settled”!
Now we know, if we didn’t before, the difference between science and scientism.
Science is just as good in draining public money as religion. They’ve got this down pat.