[{"command":"openDialog","selector":"#drupal-modal","settings":null,"data":"\u003Cdiv id=\u0022republish_modal_form\u0022\u003E\u003Cform class=\u0022modal-form-example-modal-form ecl-form\u0022 data-drupal-selector=\u0022modal-form-example-modal-form\u0022 action=\u0022\/en\/article\/modal\/7289\u0022 method=\u0022post\u0022 id=\u0022modal-form-example-modal-form\u0022 accept-charset=\u0022UTF-8\u0022\u003E\u003Cp\u003EHorizon articles can be republished for free under the Creative Commons Attribution 4.0 International (CC BY 4.0) licence.\u003C\/p\u003E\n \u003Cp\u003EYou must give appropriate credit. We ask you to do this by:\u003Cbr \/\u003E\n 1) Using the original journalist\u0027s byline\u003Cbr \/\u003E\n 2) Linking back to our original story\u003Cbr \/\u003E\n 3) Using the following text in the footer: This article was originally published in \u003Ca href=\u0027#\u0027\u003EHorizon, the EU Research and Innovation magazine\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003ESee our full republication guidelines \u003Ca href=\u0027\/horizon-magazine\/republish-our-stories\u0027\u003Ehere\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003EHTML for this article, including the attribution and page view counter, is below:\u003C\/p\u003E\u003Cdiv class=\u0022js-form-item form-item js-form-type-textarea form-item-body-content js-form-item-body-content ecl-form-group ecl-form-group--text-area form-no-label ecl-u-mv-m\u0022\u003E\n \n\u003Cdiv\u003E\n \u003Ctextarea data-drupal-selector=\u0022edit-body-content\u0022 aria-describedby=\u0022edit-body-content--description\u0022 id=\u0022edit-body-content\u0022 name=\u0022body_content\u0022 rows=\u00225\u0022 cols=\u002260\u0022 class=\u0022form-textarea ecl-text-area\u0022\u003E\u003Ch2\u003EUnearthing evidence for the origins of plate tectonics\u003C\/h2\u003E\u003Cp\u003EThe theory of plate tectonics \u2013 which describes how the Earth\u2019s crust is separated into plates that float and slide on a layer of malleable rock below \u2013 became widely accepted by science around 50 years ago. The process is believed to have largely shaped the world around us by\u0026nbsp;enabling continents to form, throwing up enormous mountain ranges when they collide, creating volcanic islands and triggering catastrophic earthquakes.\u003C\/p\u003E\u003Cp\u003EBut there is still debate about exactly how and when in our planet\u2019s 4.5-billion-year history the plates formed, estimates vary from less than one billion to 4.3 billion years ago.\u003C\/p\u003E\u003Cp\u003EIt is also unclear exactly how quickly plate tectonics evolved, says Dr Hugo Moreira, a geologist at the University of Montpellier in France. Did Earth\u2019s crust split abruptly into multiple plates and start moving over just tens of millions of years, or was the process far more gradual, taking hundreds of millions of years or more?\u003C\/p\u003E\u003Cp\u003EUnderstanding this could prove crucial for understanding not just how the planet itself has evolved, but also how life may have been kickstarted on Earth. The conditions created by plate tectonics are thought to have helped make Earth hospitable to life in the first place and also provided vital nutrients needed for complex multicellular life to prosper.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECrystal time capsules\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDr Moreira and his colleagues are seeking answers to these questions inside tiny zircon crystals, which are time capsules of Earth\u2019s distant past due to their extreme robustness. They are often found preserved in rock despite the action of continual weathering and geological events.\u003C\/p\u003E\u003Cp\u003EMany of these crystals have previously been dated by analysing the radioactive decay of isotopes \u2013 different forms of elements \u2013 that they contain. Some have been found to date as far back as \u003Ca href=\u0022https:\/\/www.nature.com\/articles\/ngeo2075\u0022 target=\u0022_blank\u0022 rel=\u0022noopener noreferrer\u0022\u003E4.4 billion years ago\u003C\/a\u003E, the earliest known fragments of Earth\u2019s crust.\u003C\/p\u003E\u003Cp\u003E\u2018That\u2019s why zircon\u2019s amazing, because although the rocks that compose the continents were destroyed, the zircon survived in the sedimentary record,\u2019 said Dr Moreira. Scientists have previously used zircon crystals to study the history of the Earth\u2019s continental crust, but it has not yet been enough to provide a definitive consensus for how plate tectonics started, he says.\u003C\/p\u003E\u003Cp\u003E\u2018After analysing hundreds of thousands of them, we still do not have an agreement,\u2019 said Dr Moreira, a member of the \u003Ca href=\u0022https:\/\/cordis.europa.eu\/project\/id\/817934\u0022 target=\u0022_blank\u0022 rel=\u0022noopener noreferrer\u0022\u003EMILESTONE\u003C\/a\u003E project being led by Dr Bruno Dhuime, a geosciences researcher for the French National Centre for Scientific Research also at the University of Montpellier.\u003C\/p\u003E\u003Cp\u003EThe researchers are hoping to use these crystals \u2013 which typically measure about a tenth of a millimetre, or roughly the thickness of a human hair \u2013 to improve our insight into the timing and evolution of plate tectonics.\u003C\/p\u003E\u003Cp\u003EThe MILESTONE group will drill down to an even tinier scale \u2013 about a hundredth of a millimetre \u2013 to examine traces of apatite and feldspar minerals trapped inside the zircon crystals. Strontium and lead isotopes in these \u2018inclusions\u2019 can add unprecedented detail on the zircon\u2019s source of formation and whether this occurred in the varying types of magma below stagnant or moving plates, says Dr Moreira.\u003C\/p\u003E\u003Cp\u003E\u2018It will be a critical step towards a better understanding of how our planet evolved,\u2019 he said. \u2018If we manage to measure the isotopic composition of these tiny inclusions, we might tell what was the composition of the rock from which the zircon crystallised. We can perhaps understand how evolved the crust was at that point and in which type of tectonic settings the magma was formed.\u2019\u003C\/p\u003E\u003Cp\u003EThis tiny-scale analysis been made possible by the set-up of a laboratory containing a specialised, highly sensitive mass spectrometer, equipment that measures the characteristics of atoms.\u003C\/p\u003E\u003Cp\u003EThe team hopes to start analysing samples next month, ultimately investigating inclusions in more than 5,000 zircons of varying age from all over the world to build up a wide-scale picture. \u2018What we want to do is pinpoint when plate tectonics went global instead of when it was localised in isolated points here and there,\u2019 said Dr Moreira.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EUnderground structures\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EAt the opposite end of the scale, other researchers have been seeking clues to the origins of plate tectonics in two massive continent-sized structures found deep underground beneath the Pacific and African plates.\u003C\/p\u003E\u003Cp\u003EThese \u2018thermochemical piles\u2019, mysterious structures located about 2,900 kilometres below the surface at the boundary between Earth\u2019s core and mantle, were discovered in the 1990s with the aid of seismic tomography \u2013 imaging from seismic waves produced by earthquakes or explosions. They were detected as potentially warmer areas of material in which seismic waves travel at different speeds than in the surrounding mantle, but there is still much debate about exactly what they are, including their composition, longevity, shape and origins.\u003C\/p\u003E\u003Cp\u003EOver the past couple of decades, a \u2018fiery\u2019 debate has arisen over their proposed link to movements on the planet\u2019s surface and so their potential involvement in the emergence of plate tectonics, explained Dr Philip Heron, a geoscientist who studied the structures as lead researcher on the \u003Ca href=\u0022https:\/\/cordis.europa.eu\/project\/id\/749664\u0022 target=\u0022_blank\u0022 rel=\u0022noopener noreferrer\u0022\u003ETEROPPLATE\u003C\/a\u003E project at Durham University.\u003C\/p\u003E\u003Cp\u003E\u2018These piles are thought to have an impact on how material moves within the planet, and therefore how the surface behaves over time,\u2019 he said. Events on the surface may in turn drive their activity.\u003C\/p\u003E\u003Cp\u003EOne theory is that these piles are stable for long geological periods and their edges correspond with the position of key features involved in plate tectonics on Earth\u2019s surface, such as supervolcanoes.\u003C\/p\u003E\u003Cp\u003EHowever, their extreme depth makes these piles difficult to observe directly. \u2018Given that these structures are in places 100 times higher than Mount Everest, they may be the largest things in our planet that we know the least about,\u2019 said Dr Heron.\u003C\/p\u003E\u003Cp\u003E\u003Cblockquote class=\u0022tw-text-center tw-text-blue tw-font-bold tw-text-2xl lg:tw-w-1\/2 tw-border-2 tw-border-blue tw-p-12 tw-my-8 lg:tw-m-12 lg:tw--ml-16 tw-float-left\u0022\u003E\n \u003Cspan class=\u0022tw-text-5xl tw-rotate-180\u0022\u003E\u201c\u003C\/span\u003E\n \u003Cp class=\u0022tw-font-serif tw-italic\u0022\u003E\u2018Given that these structures are in places 100 times higher than Mount Everest, they may be the largest things in our planet that we know the least about.\u2019\u0026amp;nbsp;\u003C\/p\u003E\n \u003Cfooter\u003E\n \u003Ccite class=\u0022tw-not-italic tw-font-normal tw-text-sm tw-text-black\u0022\u003EDr Philip Heron, Durham University, UK\u003C\/cite\u003E\n \u003C\/footer\u003E\n\u003C\/blockquote\u003E\n\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ESupercomputer power\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EThe TEROPPLATE project harnessed supercomputer power to investigate. Using more than 1,000 computers working in tandem, the team developed 3D models of Earth to show how the assumed chemical composition of large hot regions deep underground might influence the formation and location of deep mantle plumes.\u003C\/p\u003E\u003Cp\u003EHowever, their models indicated that the piles may be more passive in plate tectonics than initially thought and that the world would still form similar geological features without them. \u2018When looking at the positioning of large plumes of material that form supervolcanoes, our numerical simulations indicated that the chemical piles were not the controlling factor in this,\u2019 said Dr Heron.\u003C\/p\u003E\u003Cp\u003EBut he added that these findings were not fully conclusive and have also opened the door to other interesting avenues for research \u2013\u0026nbsp;such as exploring the implications that these structures are constantly moving through the mantle rather than being largely stationary.\u003C\/p\u003E\u003Cp\u003E\u2018It gives weight to the theory that the chemical piles may not be rigid and fixed in our planet, and that the deep Earth may evolve as readily as the continents on our surface move around,\u2019 he said. \u2018It\u2019s a push to start looking deeper.\u2019\u003C\/p\u003E\u003Cp\u003ESome of TEROPPLATE\u2019s results also indicate that the piles may have been robust enough to survive Earth\u2019s earliest beginnings. That makes it feasible for them to have been around for the start of plate tectonics and thus to have had roles in the process that we don\u2019t yet know about, adds Dr Heron.\u003C\/p\u003E\u003Cp\u003EAll of this could have implications for understanding our own place on Earth too. If, for instance, plate tectonics evolved rapidly early in Earth\u2019s history, it may raise questions such as why complex life didn\u2019t emerge earlier or just how closely the two are linked, says Dr Moreira.\u003C\/p\u003E\u003Cp\u003E\u2018To fundamentally understand where plate tectonics comes from is potentially the essence of life,\u2019 added Dr Heron. \u2018On Earth, there\u2019s not a thing that hasn\u2019t been impacted by it.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThe research in this article was funded by the EU. 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