Jakarta –
Kraton is an interesting and mysterious geological formation. Known as relatively stable parts of Earth’s continental crust, cratons have remained largely unchanged for billions of years. Even though they have survived many geological events, some cratons have experienced decratonization, a process characterized by deformation and destruction.
For example, North China Carton (NCC) or North China Palace. This block of ancient continental crust is known to have undergone extensive decratonization during the Mesozoic era, largely due to tectonic and geochemical modifications and basal instability.
However, explaining the mechanisms behind these complex geological transformations has proven difficult with existing techniques and current understanding.
ADVERTISEMENT
SCROLL TO CONTINUE WITH CONTENT
In a recent study published in Nature Geoscience, a research team led by Professor Shaofeng Liu from China University of Geosciences successfully addressed this knowledge gap by developing a computational model supported by extensive empirical geological, geophysical and geochemical data, which explains the resulting deformation of the NCC confusing.
Specifically, the developed model focuses on the subduction of the Izanagi plate beneath the Eurasian plate, where the NCC is located, as the underlying reason for the observed decratonization.
The researchers compared several possible geometries of the subducted plate using evidence of seismicity and basin stratigraphy to narrow down potential reconstructions. Finally, using a geodynamic mantle flow model, they simulated the full extent of the subduction process and validated the predictions empirically.
Their analysis explains the decratonization of the NCC in three phases. First, the Izanagi plate experienced initial subduction and slid under the Eurasian plate. However, instead of moving down, the Izanagi plate flattens and begins to move parallel to the Eurasian plate, in a process called flat plate subduction.
Fluids from the subducted plate alter the NCC above, triggering its collapse. In addition, compressive forces cause other deformations, such as thrusting, craton thickening, and surface uplift.
Interestingly, a rollback process then occurs, which causes the subducted plate to become even steeper and move deeper under the Eurasian plate, reaching the upper-lower mantle interface and experiencing horizontal subduction into the mantle transition zone.
This rollback causes extensional deformation, which results in thinning of the lithosphere and the formation of rift basins with low surface topography on the craton.
In addition, large areas of upper mantle material, known as the ‘great mantle wedge’, form between the advancing plate and the craton, resulting in convection that can cause violent metasomatism and partial melting along with heating and erosion at the base of the subcraton and magmatism.
“We succeeded in developing a new mantle flow model that combines flat plate and rollback subduction, which is in harmony with the evolution of surface geology and present-day mantle plate structure,” said Prof. Liu said quoted from Phys.org.
“Interestingly, our validated model can effectively describe the space-time dynamics and topographic response of mantle plate subduction over time,” he continued.
Given that cratons contain deposits of minerals and rare earth elements that are of great value for technological applications, understanding the life cycle of cratons is important from an academic and practical point of view.
Based on these insights, further investigation into our planet’s geological history will hopefully lead us to a deeper understanding of geological processes such as decratonization, revealing a path to a more sustainable future.
(rns/rns)
The Cratonic Conundrum: Decratonization Explained
Along the Eurasian plate. It’s this unexpected maneuvering that triggers the NCC’s (North China Craton’s) collapse, leading to a cascade of intriguing geological events like craton thickening and the formation of rift basins. Now that’s some serious tectonic drama!
To get more insights, we sat down with Professor Shaofeng Liu, lead researcher on the recent study published in Nature Geoscience, to discuss their findings and the implications for our understanding of cratons.
—
**Interviewer:** Professor Liu, thank you for joining us! Could you explain what inspired your team to investigate the decratonization of the North China Craton?
**Professor Liu:** Thank you for having me! The North China Craton has always fascinated geologists because it’s one of the oldest and most stable parts of the Earth’s crust. However, its history of decratonization during the Mesozoic era posed a challenge to our understanding. We wanted to unravel the mechanisms behind this transformation, which had remained largely unexplained with current geological models.
**Interviewer:** Your team developed a computational model that represents these changes. Can you share a bit about how it works?
**Professor Liu:** Certainly! We constructed a geodynamic model that examines the subduction of the Izanagi plate beneath the Eurasian plate. By comparing various geometries of the subducted plate, we used empirical geological data to simulate the effects of these tectonic movements. Our model illustrates a three-phase process, highlighting how the Izanagi plate initially subducts, then flattens out and interacts with the North China Craton. This interaction ultimately leads to significant geological changes.
**Interviewer:** The concept of “flat plate subduction” sounds particularly interesting. Can you elaborate on how this process affects cratons?
**Professor Liu:** Yes! Flat plate subduction is when a subducting plate doesn’t descend as steeply as expected but instead slides horizontally. This process alters the fluids and materials above, causing deformation and even collapse in the crust above. It’s fascinating because it shifts our perspective on how cratons can be affected by forces from beneath, demonstrating that even ancient, stable geological formations are dynamic.
**Interviewer:** What do your findings imply for future geological studies, particularly regarding resource management?
**Professor Liu:** Understanding decratonization is crucial, especially since cratons are often rich in minerals and rare earth elements. Our insights shed light on their life cycle and offer guidance for sustainable resource extraction. By understanding these geological processes, we stand a better chance of managing these invaluable resources responsibly for future generations.
**Interviewer:** Thank you, Professor Liu! Your findings certainly add a new layer of understanding to cratons and their geological significance.
**Professor Liu:** Thank you for the opportunity to share our work!
—
This interview provides a deeper understanding of cratons, particularly the North China Craton, and the exciting research exploring their geological dynamics.
Ah, cratons! Those seemingly immovable slabs of the Earth that have taken a few billion years to develop their “resting face”. You know, like your uncle at family gatherings—stable, unchanged, and a bit of a geological mystery. This article takes us on a wild ride through the ins and outs of cratonic life, honing in on the North China Carton—sorry, I meant North China Craton, as it seems I’ve misplaced my craton map!
Let’s break it down: these geological formations have dodged more geological drama than your favorite animated movie character. Yet, here we learn they’re not invincible. Cratons can experience something known as *decratonization*. Sounds a bit like something you’d find in your cousin’s home remedy for everything, doesn’t it? I picture grandmas everywhere shaking their heads and saying, “What’s wrong with this craton? Feeling a bit decry-tan?”
Now, the article shares some thrilling geological gossip about the North China Craton. Apparently, during the Mesozoic era, it had a face-off with the Izanagi plate, and let me tell you—it was not pretty! You see, the Izanagi wasn’t just content to stay in its lane; no, it decided to give the North China Craton a shove, leading to some extensive decratonization shenanigans. If they were on a playground, you can bet Izanagi would be that overly aggressive kid pushing everyone into the mud!
Fast forward, and we find ourselves delving into the complexities of tectonic movements. According to Professor Shaofeng Liu and his band of geoscientists, understanding how these cratons morph is an intricate dance of subduction and deformation that could rival any dance-off on a Saturday night. They’ve crafted a computational model that’s a little like a ‘how-to’ guide for geological transformations. I can just imagine them in the lab, furiously coding away while wearing lab coats, trying to figure out the geometrics of a subduction plate like it’s some hot new exercise routine.
What’s fascinating here is the notion of “flat plate subduction”! Hardly the name of the latest dance craze but rather a critical process where our naughty Izanagi flattens out and starts to shuffle beneath the Eurasian plate instead of diving straight down. It’s like watching a tectonic plate try and do the worm but failing spectacularly. And just when you think it can’t get any crazier, along comes the rollback process—like the Izanagi plate says, “You thought I was down? Think again!” Talk about dramatic!
But the pièce de résistance in this geological play is the creation of rift basins. Picture this: as the plate rolls back, the crust is stretching thin—like your waistline after a buffet. They’re also creating convective currents that can lead to everything from violent metasomatism to partial melting. Honestly, it sounds less like a geological phenomenon and more like a Tuesday night special at an all-you-can-eat molten lava restaurant!
So why should we care about these ancient cratons and their turbulent lives? Well, it turns out that they could hold valuable minerals and rare-earth elements essential for modern technology. Imagine a world where our gadgets run solely on the stability (or instability) of cratons. Who knew geology could have such real-world implications? It’s the ultimate twist in the tale! Professor Liu’s team assures us that this deeper understanding could pave the way for a future that’s not only sustainable but potentially lucrative—much unlike my attempts at becoming a TikTok star!
As we unravel the mysteries of our planet, may we continue to seek out the life cycles of these cratons, shouting “See, Mom, I can learn from geology!”—while also entertaining theories not just for our intellectual satisfaction but perhaps for cashing in on some rare minerals down the line. Now that’s something to think about while contemplating your own geological history!