https://phys.org/news/2025-04-earth-mantle-ancient-ancestors-elephants.html

"In a paper published in Nature Reviews Earth & Environment, an international team of researchers investigated the formation of a large land bridge that connected Asia and Africa 20 million years ago, through what is now the Arabian Peninsula and Anatolia.

***

"This gradual uplift of land enabled the early ancestors of animals such as giraffes, elephants, rhinoceroses, cheetahs, and even humans, to roam between Africa and Asia. The appearance of the land ended a 75-million-year-long isolation of Africa from other continents.

***

"The story begins 50–60 million years ago, when a slab of rock sliding into Earth's mantle created a "conveyor belt" for hot rocks to boil up in an underground plume that reached the surface some 30 million years later. This convective activity in the mantle, coupled with the collision of tectonic plates, created an uplift in land that contributed to closing the ancient Tethys Sea, splitting it into what is now the Mediterranean and Arabian Seas, and created a landmass that bridged Asia and Africa for the first time.

"The study's lead author Eivind Straume analyzed the wide-ranging consequences of this geologic activity while he was a postdoctoral fellow at the Jackson School. He said the appearance of the land bridge and animal evolution go hand in hand.

"'The shallow seaway closed several million years before it otherwise likely would have due to these specific processes—mantle convection and corresponding changes in dynamic topography," said Straume, who is now a postdoctoral fellow at NORCE Norwegian Research Center and The Bjerknes Center for Climate Research. "Without the plume, you could argue that the continental collision would have been different."

"In this case, timing is everything. If it had been an additional million years before Africa and Asia were connected, the animals that made their way into and out of Africa could have been on a different evolutionary path. That includes the ancestors of today's humans.

"Several million years before the land bridge had completely closed, the primate ancestors of humans came to Africa from Asia. While those primates ended up going extinct in Asia, their lineages diversified in Africa. Then when the land bridge fully emerged, these primates re-colonized Asia."

Comment: contingent events strongly effected migrations and evolution. It is a two-way street: life transforms the Earth and a changing Earth transforms life.

https://www.universetoday.com/168961/life-on-earth-needed-unmelted-asteroids/

"In space exploration, volatiles are defined as the six most common elements in living organisms, plus water. Earth had enough volatiles for life to start here, but it might not have been that way. Researchers from the University of Cambridge and Imperial College London now think they have a reason why Earth received as many volatiles as it did – and thereby allowed it to develop life in the first place.

"One characteristic of volatiles that makes them both difficult to deal with but easy to transport is that they vaporize at relatively low temperatures. Granted, a relatively low temperature could be 950°C for zinc, the volatile the researchers chose to look at.

"They chose zinc because it has a unique composition when captured in meteorites, allowing researchers to identify its source based on that composition. Previously, some of the same researchers had found that the zinc found on Earth had come from different parts of our solar system. About half had originated out past Jupiter, while half came from closer to home.

***

"Radiation was everywhere in the early solar system, and many planetesimals that formed during this period were subjected to it. Notably, the heat from these radiation sources caused the planetesimals’ volatiles to vaporize and be lost to space. So, the researchers at Cambridge and ICL thought they might be able to differentiate the age of the source of some of those volatiles – particularly zinc.

"It turns out that they could. They measured the zinc concentration in many meteorites whose originating planetesimal was known. They then modeled where the Earth received its zinc from. Since zinc is one of the vital volatiles thought to be essential to the development of life, this model could help understand how life might (or might not) develop on other worlds.

"They found that the vast majority (about 90%) of the Earth’s zinc was contributed by planetesimals that weren’t subjected to the high radiation levels of the early solar system. In essence, they were the ones whose volatiles weren’t vaporized, allowing them to contribute more of these valuable, life-giving materials despite only contributing 30% of the Earth’s overall mass.

"Additional work is needed to study whether similar heating effects affected the amount of other volatiles delivered to the early Earth. And even more work is required to model how that volatile delivery model might work for other planets, such as Mars, or even exoplanets further afield.

"But for now, this is another piece of the puzzle that answers an important question about the early solar system. And, maybe more importantly, it shows how many things have to go right for life to develop in the first place." (my bold)

Comment: the bold above is right on point. Life is here following a million (?) or more contingencies. Only design can achieve this.

https://www.sciencealert.com/colossal-impact-3-billion-years-ago-may-have-boosted-life-...

"Some 3.26 billion years ago a giant rock between 50 and 200 times the size of the Chicxulub dino-killer smacked into our planet. According to a team led by geologist Nadja Drabon of Harvard University, the upheaval resulting from this gobsmackingly-colossal impact would have churned up nutrients that gave a select few early microbes a boost.

***

"We don't know, firsthand, what a giant meteorite impact does to our planet. That's a good thing, overall. But we are able to model and simulate what happens, reconstructing events based on mineral deposition in the geological record.

"A formation known as the Barberton Greenstone Belt in South Africa contains evidence of a giant impact that shook Earth 3.26 billion years ago, an event known as S2. Drabon and her colleagues performed a painstaking characterization of the minerals in the S2 rock layer, and devised a reconstruction of the sequence of events that followed.

"It still would have been pretty devastating. The heat from the collision would have boiled off the top layer of the ocean, while the impact itself is predicted to have sprayed dust and debris into the atmosphere, creating a thick haze that blocked the sunlight and stymied photosynthetic microbes living in shallow waters.

"There also would have been a huge tsunami that dredged the ocean floor, bringing material usually sequestered in the depths to the surface.

"Although this would have harmed many of the burgeoning life forms that had been eking out an existence for just a few hundred million years at this point, it would have been a boon to some.

"The meteorite itself would delivered a burst of phosphorus, for example, while the waters dredged up from the seafloor would have been rich in iron. Both elements would have fed any microbes capable of metabolizing them, causing a brief, but significant, spike in their numbers before Earth settled back down into a more stable existence. This would especially have been true for iron-metabolizing microbial blooms in shallow waters.

"'We think of impact events as being disastrous for life, but what this study is highlighting is that these impacts would have had benefits to life, especially early on," Drabon says. "These impacts might have actually allowed life to flourish." (my bold)

"It would be more than 2.5 billion years before multicellular organisms would emerge, introducing their own significant changes to Earth's biosphere. And dinosaurs didn't appear until about 250 million years ago, give or take, reigning until the Chicxulub meteorite triggered the Cretaceous-Paleogene extinction 66 million years ago.

"Even that devastating impact – the only meteorite we've confidently linked to an extinction event – opened new avenues for life to thrive. With the decline of the non-avian dinosaurs, mammals rose to fill the vacated ecological niches; without that devastation, it's possible that humanity would never have emerged.

"So, while it is true that a massive meteorite impact has significant deleterious effects for some organisms, it can benefit others in unexpected ways. In fact, it's entirely possible that repeated early impacts altered Earth in ways that primed it for the evolutionary explosions that would follow.

"'Our work suggests that on a global scale, early life may have benefitted from an influx of nutrients and electron donors, as well as new environments, as a result of major impact events," the researchers write."

Comment: planes using radar and laser instruments can map the Earth's surface for these craters to then explore. We must have had lots of them based on looking at the Moon. We are here so they must have been beneficial.

https://phys.org/news/2024-07-confined-electric-reveals-dielectric-response.html

"When water gets inside nanopores with sizes below 10 nanometers, new physics emerge: new phases of ice were observed and ultrafast proton transport was measured. Confined water also plays a role in biology, where aquaporins cross cellular membranes to allow specific transport of water and other small molecules through nanometer-scale channels.

***

"The authors have found an increase in the ability of water to screen electric fields applied along the axis of the one-dimensional nanopore. This enhancement arises from a longer-range alignment of water dipoles under confinement relative to the bulk fluid, leading even to the formation of exotic phases of water (ferroelectric ices) under extreme confinement.

"'It's necessary to understand the ability of the confined liquid to screen electric fields and how this varies from the bulk environment," said LLNL scientist Marcos Calegari Andrade, lead author of the paper. "An improved understanding of the dielectric response of confined water is important not only for advancing separation technologies but also for other emerging applications, such as energy storage and conversion."

***

"'Our work reveals peculiar impacts of 1-D hydrophobic nanoconfinement, not only on the dielectric constant, but also on the electronic structure of water that cannot be observed with simulations based on conventional parametric force fields," Calegari Andrade said."

Comment: this characteristic helps drive dissolved material across membranes pores. Hydrogen and oxygen were early formed elements in preparation for life to appear.

https://www.sciencemagazinedigital.org/sciencemagazine/library/item/12_july_2024/420649...

"By using a form of artificial intelligence (AI) to analyze some of the oldest crystals on the planet, researchers have concluded that plate tectonics—the planet-scale geological machinery that floats giant slabs of crust across and sometimes into Earth’s mantle—began much earlier than many scientists had assumed.

"The researchers find evidence for a start more than 4 billion years ago, during the Hadean eon—just a few hundred million years after the planet’s formation. The work suggests tectonics might have had an early hand in creating the first land and helping life begin, says Ross Mitchell, a geophysicist at the Chinese Academy of Sciences who coauthored the new study, which was published this week in the Proceedings of the National Academy of Sciences. “Hadean Earth would have been habitable, permitting the origin of life not only at hydrothermal vents, but also in Darwin’s ‘warm pools’ at Earth’s surface,” he says.

***

"The oldest zircons, discovered in Australia’s Jack Hills, date back to 4.3 billion years ago. Zircons can crystallize out of fresh magma from the mantle, much like the ocean crust of today, but they can also form from sedimentary rocks on land that wash into the ocean, sink back into the mantle, and re-emerge in later bursts of igneous activity as granites. These resurfaced “S-type” zircons provide evidence of the existence of both continents and the subduction process, Mitchell says.

***

'Mitchell and colleagues then applied the trained algorithms to 971 ancient Jack Hills zircons with uncertain origins. Overall, they found that more than one-third were S-type, including a few that were up to 4.2 billion years old. Mitchell and his team have “something that looks like it could be a really useful tool,” says Beth Ann Bell, a geochemist at the University of California, Los Angeles. “This is significant not only for the early Earth, but for going throughout the geological record.”

***

"...evidence for early plate tectonics is growing—at least based on the stories preserved in the Jack Hills zircons. In April, researchers reported that freshwater was involved in the formation of 4-billion-yearold zircons—another sign that continents, and presumably, plate tectonics, existed at the time (Science, 3 May, p. 497).

"What is needed now are additional ancient zircons from places other than Australia, Fu says. The Jack Hills zircons could record events from one exceptional region that’s not representative of the globe. Still, it may be time to assume plate tectonics is nearly as old as the crust itself, Fu says—at least until it can be disproved."

Comment: it is like fine tuning evidence for design. Plate tectonics create life and appear in just 300 million years after the Earth formed. More evidence for design.

https://www.sciencenews.org/article/weaker-magnetic-field-marine-life-big

"Earth’s magnetic field protects life from harmful cosmic radiation. But sometime between about 590 million and 565 million years ago, that security blanket seems to have been much thinner — with far-reaching effects for the development of life on Earth, researchers suggest.

"A weaker magnetic field could account for the higher levels of oxygen recorded in the Earth’s atmosphere and oceans around that time — and for the ensuing proliferation of macroscopic marine animals, the team reports in the May 2 Communications Earth & Environment.

***

"Now, the same team has examined rocks from Brazil dating to about 590 million years ago. Earth’s magnetic field was even weaker back then, the researchers found — just one-thirtieth the modern-day value. That’s the lowest magnetic field strength ever measured for our planet, Tarduno says. “The field almost completely collapsed.”

"If Earth’s magnetic field remained low during the roughly 25-million-year interval bracketed by those samples — and less-precise data from other teams suggest that it did — that’s a remarkable coincidence, Tarduno says. Earth’s magnetic field was dramatically weaker right around the time of the Ediacaran Period, when oxygen levels increased in both the atmosphere and oceans; rock records show higher-than-normal levels of oxygen around that time. It’s also a period when macroscopic animals began to proliferate in the world’s oceans.

"Perhaps there’s a link there, Tarduno and his colleagues propose in the new paper. A weaker magnetic field would have meant less protection from energetic cosmic particles. “Our shield was down,” Tarduno says. Those particles would have broken apart water molecules in the early Earth’s atmosphere. Hydrogen, being extremely light, would have readily escaped into space, while oxygen would have remained behind. Over time, that imbalance would have tipped the scales in favor of a more oxygen-rich atmosphere and oxygen-enriched oceans, the researchers suggest.

"The larger, more mobile animals that the fossil record shows developed during the Ediacaran Period would have needed all that oxygen, Tarduno and his collaborators suggest. It’s no secret that bigger animals require more oxygen than their microscopic brethren, Tarduno says. “This oxygenation set the stage for large life.'”

Comment: It seems our magnetic field plays a dynamic role in its pervasive influence on life at all times.

https://www.sciencemagazinedigital.org/sciencemagazine/library/item/03_may_2024/4192470...

"Tiny grains of a mineral called zircon might have witnessed the fall of rain on Earth’s earliest dry land some 4 billion years ago, when oceans likely covered most of the planet. The chemical composition of the crystals, plucked from rocks in Australia, hint that they formed from magmas doped with freshwater, a team of scientists argues. That would only have been possible on terra firma, they say.

“'We found evidence for two things: There was land above sea level and, at the same, that this land interacted with freshwater,” says Hamed Gamaleldien, a geochemist at Khalifa University who presented the results last month at a conference of the European Geosciences Union. “This means you start to have the hydrological cycle, and you started to have the recipe for the start of life.”

***

"The zircons represent a rare report from the mysterious Hadean, the geological time period that ended about 4 billion years ago, 500 million years after Earth’s formation. The planet, originally a ball of magma, had cooled off and formed a crust. Somehow, perhaps from a bombardment of water-rich asteroids, it had accumulated a global ocean. Earth may have remained watery for quite some time— at least until tectonic processes began to recycle Earth’s crust into its interior, and magma bubbled up in chains of island volcanoes that eventually fused into continents.

"Much of this is guesswork, because almost no rock survives from the Hadean. The oldest rock with a reliable age—a gneiss from Canada—is 4.03 billion years old. The only surviving material from before then are zircons, found embedded in younger rock, which are as much as 4.4 billion years old. “Just about any information that we can get from these Hadean zircons is useful because it’s our singular record of the Earth’s first 500 million years,” says geologist Stephen Mojzsis of the HUN-REN Research Centre for Astronomy and Earth Sciences.

"Zircons are tough little minerals, often outliving the original rock they formed within. For example, Hadean zircons found in Australia’s Jack Hills sit in rock that’s about 3 billion years old—having eroded out of even older rocks that have long since disappeared. Zircons contain small amounts of elements such as uranium that allow them to be precisely dated, as well as other clues about ancient Earth. Researchers have used zircons to try to date the onset of plate tectonics and the origin of continental crust. They even offer hints of the origin of life: In 2015, Bell and her colleagues found bits of graphite in a 4.1-billion-year-old zircon that might have been derived from biological carbon.

***

"Before Gamaleldien and his colleagues could make the measurements, they had to collect, polish, and individually inspect thousands of zircons from two rock chunks pulled from the Jack Hills. They analyzed about 1400 zircons that were between 1.85 billion and 4.28 billion years old.

***

"To be certain, the researchers performed tens of thousands of computer simulations of zircons forming from magmas mixed with seawater, rainwater, or some combination of both. Only with at least some freshwater could the team reproduce the exceptionally light isotopic signature of their zircons.

***

"If Gamaleldien and his colleagues are right, however, the late Hadean might have been habitable long before the appearance of the first fossils. Not all hypotheses for the origins of life require dry land. But some invoke freshwater hot spring environments. Gamaleldien hopes his discovery will spark renewed interest in a search for life before 4 billion years. “Whether there’s life or not, we don’t know,” he says. “But you had the recipe.'”

Comment: fossilized stromatolites from 3.8 byo support the zircon theory. What is apparent is the Earth was barely formed before life tried to appear. The whole story looks like a designed process following the purpose of creating life, ending with humans. Looked at as a series of necessary contingencies, think of what the odds are if it is all by natural chance. Impossibly an enormous set of odds.

https://www.livescience.com/planet-earth/earths-magnetic-field-formed-before-the-planet...

"Earth's magnetic field may have been similarly as strong 3.7 billion years ago as it is today, pushing the earliest date for this planetary protective bubble back 200 million years.

"The timing puts the magnetic field in play around the same time life was first emerging on Earth. The oldest fossils on the planet — bacterial mats called stromatolites — date back 3.5 billion years, with some researchers claiming to have found stromatolites as old as 3.7 billion years.

"The new study suggests that at that time, the planet had a protective magnetic bubble around it that deflected cosmic radiation and damaging charged particles from the sun.

"However, the flow of solar charged particles was much stronger at that time, said Claire Nichols, an Earth scientist at the University of Oxford and lead author of the study, which was published April 24 in the Journal of Geophysical Research. That strong "solar wind" would have stripped away the magnetosphere protecting the planet, meaning Earth was far less shielded than it is today. That finding has implications for the search for alien life.
'
"When we're looking for life on other planets, having a magnetic field is not necessarily key," Nichols told Live Science. "Because actually, with a much smaller magnetosphere, it still looks like life was able to develop."

"The hunt for extraterrestrial life is only one reason to wonder about Earth's magnetic field. Not every planet has a magnetosphere, and researchers aren't quite sure what kicked Earth's into gear. Today, the magnetic field is driven by the churning of the liquid part of the core and the transfer of heat from the solid inner core to the convective outer core as the former cools. But researchers think the core didn't solidify until about a billion years ago.

"Nichols and her team went far out of the way to seek out signs of the ancient magnetic field — 93 miles (150 kilometers) inland of Nuuk, Greenland, to a spot on the edge of the ice sheet accessible only by helicopter.

***

"Using these methods, the researchers found that 3.7 billion years ago, the magnetic field was at least 15 microtesla in strength. That's half the average strength of the magnetic field today. But it's a lower-end estimate, Nichols said, so it's possible that the field back then was around as strong as it is now.

"'Whatever is driving the magnetic field in the core was just as powerful before the core was solidified," Nichols said.

"The researchers are now interested in delving more deeply into the connections between the ancient magnetic field and Earth's atmosphere. Around 2.5 billion years ago, the atmosphere suddenly experienced a flood of oxygenation. This was partially due to the development of photosynthesis, Nichols said, but the strength of the magnetic field can affect which gases stay within the atmosphere and which ones escape into space.

"'I'm really interested to know if the magnetic field has played a role in the evolution of Earth's atmosphere over time," Nichols said.

Comment: Although this article does not worry as much about how magnetic field protects us as other articles point out, I find it amazing the Earth had an early field before the iron core was formed. Surely it was/is protective. Was God watching over?

https://phys.org/news/2023-12-meteorites-source-nitrogen-early-earth.html

"Micrometeorites originating from icy celestial bodies in the outer solar system may be responsible for transporting nitrogen to the near-Earth region in the early days of our solar system. That discovery was published in Nature Astronomy by an international team of researchers, including University of Hawai'i at Mānoa scientists, led by Kyoto University.

"Nitrogen compounds, such as ammonium salts, are abundant in material born in regions far from the sun, but evidence of their transport to Earth's orbital region had been poorly understood.

***

"Like all asteroids, Ryugu is a small, rocky object that orbits the sun. The Japan Aerospace Exploration Agency's Hayabusa2 spacecraft explored Ryugu and brought material from its surface back to Earth in 2020. This intriguing asteroid is rich in carbon and has undergone significant space weathering caused by micrometeorite collisions and exposure to charged ions streaming from the sun.

***

"...Using an electron microscope, they found that the surfaces of the Ryugu samples are covered with tiny minerals composed of iron and nitrogen (iron nitride: Fe4N).

"'We proposed that tiny meteorites, called micrometeorites, containing ammonia compounds were delivered from icy celestial bodies and collided with Ryugu," said Toru Matsumoto, lead author of the study and assistant professor at Kyoto University. "The micrometeorite collisions trigger chemical reactions on magnetite and lead to the formation of the iron nitride."

"The iron nitride was observed on the surface of magnetite, which consists of iron and oxygen atoms. When magnetite is exposed to the space environment, oxygen atoms are lost from the surface by the irradiation of hydrogen ions from the sun (solar wind) and by heating through micrometeorite impact. These processes form metallic iron on the very surface of the magnetite, which readily reacts with ammonia, creating ideal conditions for synthesis of iron nitride."

Comment: a very reasonable analysis. Nitrogen is required for life to form. It conforms with my thesis God prefers to evolve His creations and a perfect Earth did evolve over time and was evolved further by the appearance of and effects of life.

https://phys.org/news/2022-09-meteorites-earth-composition-collisional-erosion.html

"A team of researchers from Université Clermont Auvergne, working with a colleague from Universität Bayreuth, has found evidence that suggests the Earth's composition changed over time during its early years via collisional erosion. In their paper published in the journal Science, the group describes their study of the amounts of samarium and neodymium in meteorites and what it showed them about the processes that led to the current makeup of the Earth.

"Prior research has suggested that planets form from collisions of material in accretion disks that build up around stars during their early years. The characteristics of such collisions are believed to play a role in the resulting makeup of the resulting planets, such as their tilt angle. Prior research has also shown that Earth has a core of iron and nickel—surrounding that is a layer of iron silicate mixed in with magnesium. The top layer is described as a layer of silicate. The density of the material decreases from the core to the crust, which, Leinhardt notes, makes the crust more vulnerable during collisions.

"Prior research has also uncovered a mystery—why does the crust contain heavier minerals? A theory has suggested that they may have been pushed upward due to incompatibilities with other materials. Unfortunately, these theories do not explain why there are higher quantities of some minerals in the crust, such as neodymium, than there should be based on how much can be measured in the core.

"Three main theories have been developed to explain this anomaly. One suggests it is an illusion; there is actually more of it in the core than can be measured. Another suggests that it is because material from the accretion disk had differences in makeup. The third suggests that as heavier materials were pushed up and accumulated in the crust, some were knocked into space during new collisions.

"In this new effort, the researchers have found evidence supporting the third theory. They measured the amounts of neodymium in meteorites, assuming they were similar in makeup to Earth's building blocks, and found that up to 20% of the Earth's outer layers could have been removed by collisions, which would explain the ratio of heavy minerals such as neodymium in the crust compared to other, lighter minerals such as samarium."

Comment: this fits my theory that God evolves everything necessary. He does not instantly create, as all history shows.

https://uncommondescent.com/intelligent-design/at-big-think-how-earths-magnetic-field-b...

"To piece together the history of Earth’s magnetic field, researchers use a technique called paleomagnetism, which involves studying the alignment of metal-bearing minerals in ancient rocks. When these rocks were still molten, these minerals would have acted like tiny compass needles, aligning with the magnetic fields they encountered. As the rocks solidified, these alignments froze in place, providing geologists with a snapshot of the rocks’ magnetic environments in the distant past.

"In 2019, one such study was carried out in Sept Îles, Quebec. Here, a team of researchers examined the alignment of minerals in rocks named anorthosites, which rose to Earth’s surface during the Ediacaran Period roughly 565 million years ago. Strangely, they found that these minerals were far less strongly aligned than those found in anorthosites from other periods, suggesting that Earth’s magnetic field dipped to just around 10% of its current strength during the Ediacaran.

"If this trend had continued, the future of Earth’s capacity to sustain life may have become far less certain. Yet since this unsettling result, researchers haven’t yet determined how long it took for Earth’s magnetic field to bounce back to its present-day strength.

"A rapid resurgence: Using paleomagnetism, a new team of researchers led by Tinghong Zhou at the University of Rochester, New York, may have solved this mystery. In their study, the researchers examined the alignments of minerals within slightly newer anorthosites, taken from the Wichita Mountains in Oklahoma. These rocks solidified during the Cambrian Period, around 532 million years ago, coinciding with an evolutionary explosion of complex, multicellular organisms.

"These anorthosites only formed around 30 million years after the Quebec samples — little more than a blip on geological timescales. Yet remarkably, the mineral alignments in the rocks showed that Earth’s magnetic field had largely regained its present-day strength during that time.

"Growing an inner core: To explain this rapid renewal, Zhou’s team that the Ediacaran Period must have coincided with the formation of Earth’s inner core. Before this happened, our planet’s magnetic field may have been generated by a dynamo effect within a purely molten core, which eventually began to collapse as the Earth’s interior cooled. Yet if a solid core began to form and grow over this period, it could have provided Earth’s field with a new lease of life.

"By modelling the flow of heat from the core to the mantle, the team predicted that the solid part of the core likely began to form around 550 million years ago, expanding to half its current width by roughly 450 million years ago.

"At this point, a shift in plate tectonics on Earth’s surface would have altered the structure of the mangle surrounding the core — triggering new patterns in heat flow that persist into the present day. This suggests that Earth’s inner core likely grew in two distinct stages, with a clear boundary between its inner- and outermost parts.

"A close call: The insights gathered by Zhou’s team offer a clearer picture of the dramatic events that once unfolded deep within our planet’s interior. They also provide new hints as to how Earth narrowly avoided a Mars-like fate, just as complex, multicellular life was beginning to emerge."

Comment: a clear view of this stage of evolution of the Earth, showing again God prefers to evolve His creations. Note how closely this is timed with the start of the Cambrian explosion.

https://www.universetoday.com/157189/would-we-have-continents-without-asteroid-impacts/

"Early Earth was a wild and wooly place. In its first billion years, during a period called the Archean, our planet was still hot from its formation. Essentially, the surface was lava for millions of years. Asteroids bombarded the planet, and the place was still recovering from the impact that formed the Moon. Oceans were beginning to form as the surface solidified and water outgassed from the rock. The earliest atmosphere was actually rock vapor, followed quickly by the growth of a largely hot carbon dioxide and water vapor blanket. Earth was just starting land masses that later became continents. For decades, geologists have asked: what started continental formation?

***

"Billions of years ago, Earth, along with the other planets, was a target for incoming asteroids. The early solar system was crawling with these chunks of rock and ice. Earth itself came together as some of those objects accreted together to make a larger world. They brought substantial amounts of minerals and water to the infant planet. During Earth’s first billion years or so, the giant impacts continued through a time called the Late Heavy Bombardment. That period ended about 3.8 billion years ago, and coincides with the formation of some of the oldest remaining rocks on the planet. (my bold)

"However, a new study out of Curtin University in Australia offers one possible explanation: ancient impacts by giant asteroids. The evidence lies in zircon crystals found in one of the oldest pieces of ancient crust on Earth. They point directly to a violent period in Earth’s early history when giant meteorites crashed to the surface, planting the seeds (as it were) of the continents that grew from eruptions spurred by the impacts.

***

"The force of the collision affects both the atmosphere and the surface. The shock wave from the incoming impactor fractures and then melts the crust in a process called “shallow melting”. The illustration below shows that process. That creates crystals that are typical of impact melt. If there’s water nearby (as there almost certainly was on early Earth), then it would also play a role in crystal formation and altering rocks. Those processes are fairly typical of the aftermath of giant impacts during the first billion years of Earth’s history. If the impact is big enough, it could deliver enough punch to trigger mantle melting. The mantle is the layer just below Earth’s crust. In such an impact, lava would pour out through the fractured crust. Impacts also throw out spherules of melted material out to great distances across the surface.

***

"Given that much of Earth’s surface has changed since the Late Heavy Bombardment through erosion and inundation, the team had to look for really old rock samples dating back to that period. That’s why they went to the Pilbara Craton. It’s a pristine example of rock formed by geologic processes and shows evidence of impact-related structures and minerals created during collisions during the Late Heavy Bombardment. Those structures could well be part of the continent-forming process.

“'By examining tiny crystals of the mineral zircon in rocks from the Pilbara Craton in Western Australia, which represents Earth’s best-preserved remnant of ancient crust, we found evidence of these giant meteorite impacts,” Johnson said. “Studying the composition of oxygen isotopes in these zircon crystals revealed a ‘top-down’ process starting with the melting of rocks near the surface and progressing deeper, consistent with the geological effect of giant meteorite impacts.”

"This study of zircon crystals and other minerals is the first solid evidence pointing toward the impact-related evolution of Earth’s continents. The study of Pilbara Craton is just the first step in understanding the role of impacts in continental formation. “Data related to other areas of ancient continental crust on Earth appears to show patterns similar to those recognised in Western Australia,” said Johnson. “We would like to test our findings on these ancient rocks to see if, as we suspect, our model is more widely applicable.'”

Comment: In the evolution of the Earth continents had to appear to allow the evolution of land animals. Note my bold: during that wild period 3.8 billion years ago, life appeared!!! We should say we come from extremophiles

https://phys.org/news/2022-08-giant-deep-ocean-life.html

"A previously overlooked factor—the position of continents—helps fill Earth's oceans with life-supporting oxygen. Continental movement could ultimately have the opposite effect, killing most deep ocean creatures.

***

"The water at the ocean's surface becomes colder and denser as it approaches the north or south pole, then sinks. As the water sinks, it transports oxygen pulled from Earth's atmosphere down to the ocean floor.

"Eventually, a return flow brings nutrients released from sunken organic matter back to the ocean's surface, where it fuels the growth of plankton. Both the uninterrupted supply of oxygen to lower depths and organic matter produced at the surface support an incredible diversity of fish and other animals in today's ocean.

"New findings led by researchers based at UC Riverside have found this circulation of oxygen and nutrients can end quite suddenly. Using complex computer models, the researchers investigated whether the locations of continental plates affect how the ocean moves oxygen around. To their surprise, it does.

***

"'Many millions of years ago, not so long after animal life in the ocean got started, the entire global ocean circulation seemed to periodically shut down," said Ridgwell. "We were not expecting to find that the movement of continents could cause surface waters and oxygen to stop sinking, and possibly dramatically affecting the way life evolved on Earth."

"Until now, models used to study the evolution of marine oxygen over the last 540 million years were relatively simple and did not account for ocean circulation. In these models, ocean anoxia—times when oceanic oxygen disappeared—implied a drop in atmospheric oxygen concentrations.

***

"This study used, for the first time, a model in which the ocean was represented in three dimensions, and in which ocean currents were accounted for. Results show that collapse in global water circulation lead to a stark separation between oxygen levels in the upper and lower depths.

"That separation meant the entire seafloor, except for shallow places close to the coast, entirely lost oxygen for many tens of millions of years, until about 440 million years ago at the start of the Silurian period.

"Circulation collapse would have been a death sentence for anything that could not swim closer to the surface and the life-giving oxygen still present in the atmosphere," Ridgwell said. Creatures of the deep include bizarre-looking fish, giant worms and crustaceans, squid, sponges and more.

"The paper does not address if or when Earth might expect a similar event in the future, and it is difficult to identify when a collapse might occur, or what triggers it. However, existing climate models confirm that increasing global warming will weaken ocean circulation, and some models predict an eventual collapse of the branch of circulation that starts in the North Atlantic.

***

"'You'd think the surface of the ocean, the bit you might surf or sail on, is where all the action is. But underneath, the ocean is tirelessly working away, providing vital oxygen to animals in the dark depths," Ridgwell said.

"'The ocean allows life to flourish, but it can take that life away again. Nothing rules that out as continental plates continue to move."

Comment: another way plate tectonics support life

https://www.sciencemag.org/news/2021/08/totally-new-idea-suggests-longer-days-early-ear...

"Now a research team has proposed a novel link between how fast our planet spun on its axis, which defines the length of a day, and the ancient production of additional oxygen. Their modeling of Earth’s early days, which incorporates evidence from microbial mats coating the bottom of a shallow, sunlit sinkhole in Lake Huron, produced a surprising conclusion: as Earth’s spin slowed, the resulting longer days could have triggered more photosynthesis from similar mats, allowing oxygen to build up in ancient seas and diffuse up into the atmosphere.

***

"Microbes that became cyanobacteria evolved the molecular machinery for photosynthesis early on, letting them convert carbon dioxide and water into sugars and oxygen. Researchers have long thought these microbes provided Earth’s initial supply of oxygen, over the eons creating an environment that favored the evolution of aerobic life in all its forms. But they always puzzled over why about a billion years passed between the first photosynthetic microbes, which fossils indicate arose about 3.5 billion years ago, and the first good geological evidence for a buildup of oxygen.

***

"Many agree that 4.5 billion years ago, a day was only about 6 hours long. By about 2.4 billion years ago, the models predict, the pull of the Moon had slowed that spin to about a 21-hour day. Earth’s rotational speed then stayed constant for about a billion years, as its gravitational pull countered the Moon’s drag. Those forces fell out of balance about 700 million years ago, because the resonance cycle between Earth and the Moon is not completely stable, and the planet’s spin slowed to its current speed, creating a 24-hour day, according to the models.

***

"...oxygen first jumped during what’s called the Great Oxygenation Event, some 2.4 billion years ago, and then again during the Neoproterozoic era, more than a billion years later. During the Paleozoic, about 400 million years ago, there was a final major increase in atmospheric oxygen.

***

"Models suggest the amount of oxygen on Earth increased in a stepwise fashion, starting with the Great Oxygenation Event (GOE) about 2.4 billion years ago, followed by a plateau for a "boring billion" years. Oxygen rose again in the Neoproterozoic Oxygenation Event (NOE) and Palaeozoic Oxidation Event (POE). Day length rose in the same stepped pattern, suggesting that the added light boosted photosynthetic microbes, fueling increases in oxygen.

"This “elegant” idea helps explain why oxygen didn’t build up in the atmosphere as soon as cyanobacteria appeared on the scene 3.5 billion years ago, says Timothy Lyons, a biogeochemist at the University of California, Riverside. Because day length was still so short back then, oxygen in the mats never had a chance to build up enough to diffuse out. “Long daytimes simply allow more oxygen to escape to the overlying waters and eventually the atmosphere,” Lyons says.

"Still, Lyons and others say, many factors likely contributed to the rise in oxygen. For example, Fischer suspects free-floating cyanobacteria, not just those in rock-affixed mats, were big players. Benjamin Mills, an Earth system modeler at the University of Leeds, thinks the release of oxygen-binding minerals by ancient volcanoes likely countered the early buildup of the gas at times and should be factored into oxygen calculations."

Comment: The Earth evolved to its present state over time. The universe evolved to its present state after the BB. Life evolved from simple Archaea. Our reality has appeared to reach its present state by processes of evolution. If God is in charge He uses evolution to reach His goals.

https://www.sciencedaily.com/releases/2021/03/210317141719.htm

"First, the geological formations that are most important for its understanding lie at the bottom of the oceans. Secondly, forces controlling the processes act below the seafloor and are hence hidden from our view. Many details of plate tectonics are therefore still unclear today.

***

"It is about so-called transform faults. "These are large offsets in the mid-ocean ridges. So far, they have been assigned a purely passive role within plate tectonics. However, our analyses show that they are definitely actively involved in shaping the ocean floors," explains Prof. Ingo Grevemeyer from GEOMAR, lead author of the study.

"A look at a global overview map of the ocean floors helps to understand the study. Even at low resolution, several tens of thousands of kilometres long mid-ocean ridges can be recognised on such maps. They mark the boundaries of the Earth's plates. In between, hot material from the Earth's interior reaches the surface, cools down, forms new ocean floor and pushes the older ocean floor apart. "This is the engine that keeps the plates moving," explains Prof. Grevemeyer.

***

"The authors of the current study have now looked at available maps of 40 transform faults in all ocean basins. "In all examples, we could see that the transform valleys are significantly deeper than the adjacent fractures zones, which were previously thought to be simple continuations of the transform valleys," says co-author Prof. Colin Devey from GEOMAR. The team also detected traces of extensive magmatism at the outer corners of the intersections between transform valleys and the mid-ocean ridges.

"Using sophisticated numerical models, the team found an explanation for the phenomenon. According to this, the plate boundary along the transform fault is increasingly tilted at depth, so that shearing occurs. This causes extension of the seafloor, forming the deep transform valleys. Magmatism at the outer corners to the mid-ocean ridges then fills up the valleys, so that the fracture zones become much shallower. Oceanic crust that forms at the corners is therefore the only crust in the ocean that is formed by two-stage volcanism. What effects this has on its composition or, for example, the distribution of metals in the crust is still unknown.

"Since transform faults are a fundamental type of plate boundary and frequent phenomenon along active plate boundaries in the oceans, this new finding is an important addition to the theory of plate tectonics and thus to understanding our planet. "Actually, the observation was obvious. But there are simply not enough high-resolution maps of the seafloor yet, so no one has noticed it until now," says Prof. Grevemeyer."

Comment: There must be mechanisms that keep the plates moving, maintaining the subduction processes that cause the recycling of various elements vital to our staying alive.

https://www.newscientist.com/article/2271279-signs-that-earth-was-once-almost-entirely-...

"Chemical signatures in 3.7-billion-year-old basalt rocks from Greenland support the long-held theory that Earth was once almost entirely molten.

"We know very little about what early Earth looked like – but one theory says that at several times it was almost entirely molten, a magma ocean. These oceans were probably caused by a series of massive impacts with other objects in our solar system that each generated enough energy to melt our planet’s interior. One of the last such collisions is thought to have formed the moon.

"Now, Helen Williams at the University of Cambridge and her colleagues have found evidence of these early magma oceans in ancient rocks.

"They collected samples of 3.7-billion-year-old basalt from the Isua supracrustal belt, an area of rocks in south-west Greenland, and measured the iron isotopes in them using chromatography and mass spectroscopy. They found unusually high levels of heavy iron isotopes – lighter ones are commonly found in younger basalt rocks.

***

"The team found that the Greenland rocks contained iron-rich minerals that hold a history of repeated crystallisation from magma oceans beginning as early as 4.1 billion years ago. Some of the minerals may have formed at least 700 kilometres below Earth’s surface.

“'The unusual ratios of iron isotopes are best explained by crystals having formed in a deep magma ocean and then being transported to the upper mantle where they melted again to form the Greenland rocks,” says Catherine McCammon at the University of Bayreuth in Germany, who wasn’t involved in the research. “Old rocks, such as the ones from Greenland, are melted reconstructions of ancient material.”

"Although this is the earliest evidence of these magma oceans, the team is confident that they existed before this. But it is difficult to find ancient rocks from Earth’s earliest days that would preserve this evidence, because any such rocks have undergone so much subsequent geological modification that their original chemical signatures are lost, says Williams."

Comment: All part of evolving a planet able to support life

https://www.sciencedaily.com/releases/2021/03/210302075346.htm

"Hours before the 2018 eruption of Sierra Negra, the Galápagos Islands' largest volcano, an earthquake rumbled and raised the ground more than 6 feet in an instant. The event, which triggered the eruption, was captured in rare detail by an international team of scientists, who said it offers new insights into one of the world's most active volcanoes.

***

"For nearly two months in 2018, lava erupted from the volcano, covering about 19 square miles of Isabela Island, the largest island in the Galápagos and home to about 2,000 people and endangered animal species like the Galápagos giant tortoise.

"'The 2018 eruption of Sierra Negra was a really spectacular volcanic event, occurring in the 'living laboratory' of the Galápagos Islands," said Andrew Bell, a volcanologist at the University of Edinburgh."

***

"The scientists captured data over 13 years as the volcano's magma chamber gradually refilled following the 2005 eruption, stressing the surrounding crust and creating earthquakes. This continued until June 2018, when an earthquake occurred on the calderas fault system and triggered the subsequent eruption, the scientists said.

"'We have this story of magma coming in and stressing the system to the point of failure and the whole system draining again through the eruption of lava flows," La Femina said. "This is the first time anyone's seen that in the Galápagos to this detail. This is the first time we've had the data to say, 'okay, this is what happened here.'"

***

"Inside the Sierra Negra caldera is a "trap-door fault," which is hinged at one end while the other can be uplifted by rising magma. The scientists found the fault caused hills inside of the six-mile-wide caldera to lift vertically by more than 6 feet during the earthquake that triggered the eruption.

"Caldera resurgence, important to better understanding eruptions, had not been previously observed in such detail, the scientists reported in the journal Nature Communications.

"'Resurgence is typical of explosive calderas at volcanoes like Yellowstone, not the kind of shield volcanoes we see in the Galápagos or Hawaii," La Femina said. "This gives us the ability to look at other volcanoes in the Galápagos and say, 'well that's what could have happened to form that caldera or that resurgent ridge.''"

Comment: In order for us to live on Earth, we must put up with this dangerous process. We need all the knowledge we can use. It is all part of a pattern that our right to life comes with good and bad issues.

https://evolutionnews.org/2021/02/what-subduction-teaches-about-intelligent-design/

"In brief, what happens is that organisms in the oceans consume elements vital for life — carbon, phosphorous, nitrogen, sulfur — and then they die and sink to the bottom of the oceans where they get buried in sediment. If this process continues unabated then over time, ocean sediment will become a sink that accumulates life-necessary elements. Over time these elements will be segregated from the biosphere, no longer available for living organisms to use and thrive.

***

"Thankfully, there is a solution for this problem on earth, and it’s called plate tectonics — or more specifically, subduction. In plate tectonics, ocean sediment is dragged down through subduction deep into the earth on the surface of the subducting slab. When material on the slab reaches a certain depth, part of the slab melts (especially the sediments on top of the slab), and the elements travel back up to the earth through plumes of magma. There they are finally released back into earth’s surface environment through volcanoes.

***

"Our results suggest that subduction, worldwide, hosts large sources of deep H2 and abiotic CH4, potentially providing energy to the overlying subsurface biosphere in the forearc regions of convergent margins. … Geochemical data from forearc mud volcanos and hydrothermal seeps suggest that life exists as deep as 15 km below the surface at convergent margins and that the essential carbon to sustain deep microbiological habitats in the forearc of convergent plate margins is provided by the metamorphic recycling of subducting slabs. … [O]ur results suggest that high-pressure serpentinization is potentially an important source of reduced volatiles to the deep subsurface biospheres of convergent margins. Considering that low temperature and pressure serpentinization also takes place at subduction zones in the shallow forearc mantle and in obducted ophiolites, we propose that convergent margins may have represented the major source of H2 and abiotic CH4 from different depths to the surface biosphere."

Comment: A highly informative article I've greatly condensed. We can't live into the future without this process continuing. Any other planetary system must have this process for life to exist, based on our knowledge of our Earth. Design must be recognized.

https://www.newscientist.com/article/2268520-earths-magnetic-field-flipping-linked-to-e...

"The most recent reversal of Earth’s magnetic field may have been as recent as 42,000 years ago, according to new analysis of fossilised tree rings. This flip of the magnetic poles would have been devastating, creating extreme weather and possibly leading to the extinction of large mammals.

"Earth’s magnetic field extends into space and is most concentrated at the north and south poles. These magnetic poles wander and occasionally reverse around every 200,000 to 300,000 years, but we have little evidence on how this impacts our planet.

"Alan Cooper at the South Australian Museum in Adelaide and his colleagues have now provided some answers. They came up with the most accurate date yet of Earth’s last magnetic field reversal called the Laschamp event, which they estimate occurred between 41,560 and 41,050 years ago and lasted less than 1000 years.

"The team calculated this estimate using radiocarbon analysis of tree rings from an ancient, fossilised kauri tree (Agathis australis) preserved in northern New Zealand wetlands.

“The tree lived right through the Laschamps and we used the shift in radiocarbon, carbon-14, in the atmosphere to detect exactly when the magnetic field collapsed,” says Cooper.

"The Earth’s magnetosphere – the region around the planet dominated by Earth’s magnetic field – weakens when the magnetic poles reverse. Cooper and his team estimate the Earth’s magnetic field was just 6 per cent of current levels during the Laschamp event.

"When the magnetic field weakens, cosmic rays enter the atmosphere and transform carbon atoms into a radioactive form called carbon-14. By measuring the levels of carbon-14 in each tree ring of the kauri tree, they were able to accurately date the Laschamp event.

"They then used climate modelling to find that several major changes coincided with the Laschamp event. The weakened magnetic field allowed more ionising radiation from solar flares and cosmic rays from space to reach Earth.

“'These damage the ozone layer and ultraviolet light comes in at very high levels,” says Cooper. This would have caused extreme weather conditions, including lightning, high temperatures and lots of sunlight – which may have been difficult for organisms to adapt to.

“'These extreme environmental changes may have caused, or at least contributed to, extinction events including those of large mammals in Australia and the Neanderthals in Europe,” says Paula Reimer at Queen’s University Belfast, who was not involved in the research. Megafauna across Australia and Tasmania – prehistoric giant mammals that existed in the Late Pleistocene – and Neanderthals in Europe went extinct around the same time as the magnetic pole reversal, 42,000 years ago."

Comment: The magnetic field protects us from most harmful rays. It is a must have. Why it flips and that lasts 1,000 years is not explained. And so it is another issue for theodicy discussion wondering if God has a reason for this phenomenon that might be required.

https://www.sciencedaily.com/releases/2020/08/200818142104.htm

"Imagine reading by the light of an exploded star, brighter than a full moon -- it might be fun to think about, but this scene is the prelude to a disaster when the radiation devastates life as we know it. Killer cosmic rays from nearby supernovae could be the culprit behind at least one mass extinction event, researchers said, and finding certain radioactive isotopes in Earth's rock record could confirm this scenario.

***

"A supernova, on the other hand, delivers a one-two punch, the researchers said. The explosion immediately bathes Earth with damaging UV, X-rays and gamma rays. Later, the blast of supernova debris slams into the solar system, subjecting the planet to long-lived irradiation from cosmic rays accelerated by the supernova. The damage to Earth and its ozone layer can last for up to 100,000 years.

***

"The team said the key to proving that a supernova occurred would be to find the radioactive isotopes plutonium-244 and samarium-146 in the rocks and fossils deposited at the time of extinction. "Neither of these isotopes occurs naturally on Earth today, and the only way they can get here is via cosmic explosions," said undergraduate student and co-author Zhenghai Liu.

***

"Researchers have yet to search for Pu-244 or Sm-146 in rocks from the Devonian-Carboniferous boundary. Fields' team said its study aims to define the patterns of evidence in the geological record that would point to supernova explosions.

"'The overarching message of our study is that life on Earth does not exist in isolation," Fields said. "We are citizens of a larger cosmos, and the cosmos intervenes in our lives -- often imperceptibly, but sometimes ferociously.'" (my bold)

Comment: Perhaps it happened in the past, but no supernova candidates are close enough to us to cause trouble now.