Latest news with #geology
Yahoo
9 hours ago
- Science
- Yahoo
Conservancy event blends nature, history and science in Union County
LEWISBURG — The Dale-Engle-Walker Property on Saturday was the place to learn about biodiversity, fossils and history. The Merrill W. Linn Land & Waterways Conservancy hosted the Living Landscape Program on the 137-acre property located at 1471 Strawbridge Road, Lewisburg. This event was in coordination with the Bucknell University Humanities Center and the Union County Historical Society. "We're all around nature, but we don't necessarily know exactly what we're looking at," Thom Rippon, of White Springs, said. "It's important to understand that, especially in the farming part of Union County. We're learning today about both the geology and biology of our wonderful land." Rippon, a member of the Conservancy, said he often participates in events like this. "It's all about preserving nature, understanding nature and conserving nature," Rippon said. Rippon and 25 people walked around the property to learn more about the geology, plants and wildlife and history of the land. Guest lecturers from Bucknell University were Dr. Beth Capaldi, Professor of Biology; Claire Campbell, Professor of History, History Department Chair, Affiliated Faculty in Environmental Studies & Sciences; and Dr. Jeff Trop, Professor of Geology. More than 410 million years ago during the Silurian Period, the Dale-Engle-Walker Property was a tropical marine setting with a reef. The nearby limestone quarry is made up of organic debris from this time period, according to Trop. Trop displayed limestone rocks with fossils in them as well as pointed out places in the 1793 house where fossils can also be located. He also explained that a few drops of acid on the limestone rocks can cause it to bubble and produce a sound and smell from the reaction. Letti Graboski, 11, of Danville, said she loves coming to the programs because of the nature walks. "The nature walks are calming," she said. Irmgard Seidl-Adams, of Lewisburg, said she is a frequent visitor to the property. The Dale-Engle-Walker is a "real gem" in Union County, she said. "The geology introduction was really nice, because I had no idea about the geology of this place," she said. "I've walked it many times. I love the plants on the ridge, but I had no idea. I'm happy with what we got." Capaldi said many large trees were part of Pennsylvania until it was forested. Those trees held a lot of communities: insects eating the foilage as well as birds eating them. "When forests are fragmented, it influences biodiversity by reducing it," Capaldi said. "It also changes ecosystem services. The ways that organisms can move naturally through normal, ecological processes of predation and competition are affected." Capaldi said the property has many unique plant communities on the limestone rocks that only grow in habitats like these. "When you go for a walk here, you're walking your dog or you're going to walk birds, there's a lot other things that are happening right behind the scenes, and that's one of the reasons why it's so valuable to us," Capaldi said. Campbell said early settlers in early 18th and 19th century believed that nature needed to be improved by humans. They believed it was "wasted" until humans applied effort, intellect, capital, technology and labor to improve the land from its wild state. She described it as a "sense of colonial entitlement, a sense of possibility of expansiveness and acquisition." Samuel Dale meant for the house to be impressive and a statement of ownership and possession. The Conservancy will host a second part to the Living Landscape Program in the fall. The date is to be determined.
Forbes
a day ago
- General
- Forbes
Rocks Date Onset Of Modern Plate Tectonics To 2 Billion Years
When plate tectonics first emerged on Earth is still debated. Some models suggest that Earth at first possessed a single protoplate covering the entire planet. This protoplate eventually broke open, the fragments forming tectonic plates. Other models suggest plate tectonics may have evolved gradually over billions of years. A new study, Xiaoli Li and colleagues from the Earth and Space Sciences Department, Peking University, published evidence from the petrologic record suggesting that the modern style plate tectonics begun in the Paleoproterozoic — over 1.6 billion years ago. The team analyzed eclogites from the Belomorian Province in Baltica. Eclogite is a metamorphic rock containing red almandine-pyrope garnet hosted in a matrix of green omphacite (a sodium-rich pyroxene). Eclogites typically results from high to ultrahigh pressure metamorphism of basaltic lava at low thermal gradients as it is subducted to the lower crust to upper mantle depths in a subduction zone. Subduction zones, where one tectonic plate slides beneath another plate, are a key element of modern plate tectonics. Radiometric dating of the rocks revealed an age around 2 and 1.8 billion years ago, making them the oldest known subduction eclogites. The protolith, the original lava rock, is even older with an age ranging between 2.7 and 2.5 billion years. The eclogite from Baltica shows some chemical similarities to 'modern' eclogite, formed just 65 million years ago, from the Himalayas. The Himalaya orogen formed when the former ocean between Asia and India was subducted, and remains of oceanic crust and continental fragments were uplifted by the collision. The authors suggest that in a similar way the eclogite from Baltica demonstrates the existence of a mountain range, comparable to the Himalaya range, on the supercontinent Columbia over two billion years ago. Plate tectonics has, so far, only been observed on Earth, and may be essential to making a world hospitable for life by constantly remixing and renewing the outer layers of the planet. The new results, together with previous research, suggests that something happened around 3.8 to 2 billion years ago, with Earth switching from a single plate towards plate tectonics and changing its geological evolution forever. The study,"Orosirian cold eclogite from Baltica marks the onset of modern plate tectonics," was published in the journal Earth and Planetary Science Letters.
Yahoo
a day ago
- Business
- Yahoo
A reservoir of gold lies hidden in Earth's core. Scientists say it's leaking
Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Gold and other precious metals are leaking from Earth's core into the layers above, eventually making their way up to the surface during the formation of volcanic islands like Hawaii, a new study suggests. The theory results from a three-year analysis of Hawaii's basaltic rocks, which originally formed from plumes of magma, or molten rock, rising from the ocean floor. Clues in the form of heavy metals found in the volcanic rocks could confirm a suspicion long held by geologists — that Earth's molten core is not isolated but likely bleeds into the rocky mantle, the layer between the planet's thin crust and the core. 'About 40 years ago, people first came up with the theory that maybe the core is losing some material into the mantle, but the signals we got so far were really ambiguous,' said Nils Messling, a geochemist at the University of Göttingen in Germany and lead author of the report, published May 21 in the journal Nature. 'Now, in my opinion, we have the first very strong evidence that some of the core is actually ending up in the mantle.' Scientists already knew that most of the gold on the planet — more than 99.95%, according to Messling — lies hidden in the molten core, along with other heavy elements such as platinum. As meteorites bombarded one another in Earth's early history, a reservoir of these precious metals developed when the core formed about 4.5 billion years ago. But this study suggests that at least a tiny amount of that gold has escaped to the surface, raising the fascinating prospect that, if the leaking continues, more and more of this precious metal could travel from the center of Earth to the crust in the future. 'Our findings not only show that the Earth's core is not as isolated as previously assumed. We can now also prove that huge volumes of super-heated mantle material — several hundreds of quadrillion metric tonnes of rock — originate at the core-mantle boundary and rise to the Earth's surface to form ocean islands like Hawaii,' said study coauthor Matthias Willbold, a professor at the University of Göttingen, in a statement. To find evidence of this core-mantle interaction, Messling and his coauthors obtained some samples of Hawaiian volcanic rocks from the Smithsonian Institution in Washington, DC. 'Some were taken by a submarine, from a deep sea volcano, but (otherwise) it's basically just very ordinary-looking basaltic rock, very unassuming, that you would find anywhere on Hawaii,' he said. 'We started with half a kilogram (1.1 pounds) of rock, we crushed it into a powder, and then we melted it in the oven with some different chemicals, to end up with a sample in liquid form.' From that sample, the team extracted all the elements in the platinum group, which includes platinum itself as well as the lesser-known rhodium, palladium, iridium, osmium and ruthenium. The scientists then focused on ruthenium, a silver-gray metal about as rare in Earth's crust as gold. 'The mantle has almost no ruthenium in it,' Messling said. 'It's one of the rarest elements on Earth. But Earth is basically made of meteorites that crashed together, and meteorites (contain) ruthenium, which went into the core when the core formed. So the mantle has next to no ruthenium, and the core has all of the ruthenium. The same with gold and platinum.' Earth's core has two layers. A hot, solid metal sphere of iron and nickel is roughly 70% the size of the moon, with a radius of about 759 miles (1,221 kilometers). A liquid metal outer core is about 1,400 miles (2,253 kilometers) thick and extends to about 1,800 miles (2,897 kilometers) below the surface, or right up to the mantle. In contrast, the mantle, which lies between the planet's outer crust and the molten core, is 1,800 miles (2,897 kilometers) of mostly solid rock. To determine whether the extracted ruthenium was originally from the core and not the mantle, the team looked at a specific isotope, or type, of ruthenium that was likely more abundant in Earth's early building materials during the time the core formed billions of years ago. 'The vast majority of gold and other precious metals like platinum were likely delivered by massive meteorite impacts during the final stages of Earth's formation — a process known as late accretion,' said Pedro Waterton, an assistant professor of geochemistry at the University of Copenhagen in Denmark who was not involved in the study. The presence of the ruthenium isotope in the basalt samples indicates that at least some of the rock was formed from material coming from the molten metallic core. That's because there is consensus, Messling said, that the material that coalesced during the early stages of Earth's formation does not exist in the meteorite record anymore. He added that the isotope signature in rocks from hotspot volcanoes like the ones in Hawaii is entirely different from any other known rock or meteorite. In other words, the ruthenium isotope Messling found was locked away in the core billions of years ago, so detecting the isotope in volcanic rocks today suggests it comes from the core. 'It's quite a novel and difficult method,' Messling said. 'We managed to measure ruthenium in rocks that have next to no ruthenium in them. In half a kilo (1.1 pounds) of rock, it was less than milligrams — a needle in a planet-sized haystack! That's quite exciting — for a geochemist, at least. It was a long but very exciting process.' So what's the connection with gold? It's chemically similar to ruthenium, Messling said, so if the core is leaking ruthenium, it is also leaking gold in similar quantities. This would be a 'minuscule' amount, however. And even if scientists wanted to extract gold directly from the source, the core-mantle boundary, that's much farther down than current technology could drill. In fact, it's about 236 times deeper than the deepest bore ever drilled — the Kola Superdeep Borehole in Russia, which reaches a depth of 7.62 miles (12.3 kilometers). Proof that the core isn't isolated is particularly thrilling because the core and the mantle shouldn't interact at all, Messling said. 'Their density is too different, like oil and water, so technically they shouldn't mix. And we still don't have a good mechanism to explain why they do. We don't really know much about the core at all,' he said. The Hawaiian rock samples suggest that the leaking process takes between 500 million and 1 billion years to complete, Messling said. 'It's something that has occurred a while ago, and we suspect that it probably has been going on forever, and it's probably still occurring now,' he explained. According to Messling, if the leaking of precious metals is an ongoing process, it could be that at least some of the gold humans have mined may have come from the core even if the quantity of core material in a single rock is negligible, and that the world's supply of gold seems to be replenishing. 'It's a very interesting idea that, although this process is tiny and has zero effect if you look at just one island, if you scale it up to 4.5 billion years it could be that it changes the composition of the Earth,' he said. Researchers who were not involved in the study expressed positive views on the findings. 'We know that the Earth was built from different generations of meteoritic material that were added progressively to the growing planet, and that precious metals from the earliest generations of meteorite material became concentrated into our planet's core while metals from meteorites added in the final stages of the Earth's growth became stranded in our planet's mantle,' said Helen Williams, a professor of geochemistry and planetary science at the University of Cambridge in the United Kingdom. The study, she added, confirms that the mantle plumes — rising jets of molten rock coming from the core-mantle boundary that create hot spots like Hawaii — do indeed contain material somehow derived from Earth's metallic core, said Williams, adding that the result was 'exciting.' Jesse Reimink, an associate professor of geosciences at Pennsylvania State University, agrees. 'This is a very old debate, and new data over the past 10 or so years has reinvigorated the possibility that the core was chemically 'leaking' into the mantle over time,' he said. 'This study really does seem to nail the conclusion — the core does contribute some material to the mantle.' The latest research also strengthens the case made in previous work that some mantle plumes incorporate material from Earth's core, said the University of Copenhagen's Waterton. Does that also mean some of the gold in Earth's crust is originally from the core? 'Yes, but probably only a very small amount,' he said.
Yahoo
2 days ago
- General
- Yahoo
James Webb telescope spots weird changes on Jupiter's icy moon Europa
When you buy through links on our articles, Future and its syndication partners may earn a commission. You'd think that icy worlds are frozen in time and space because they're — well — icy. However, planetary scientists know that all worlds can and do change, no matter how long it takes. That's true for Europa, one of Jupiter's four largest moons. Recent observations made by the James Webb Space Telescope (JWST) zero in on the Europan surface ices and show they're constantly changing. Dr. Ujjwal Raut of the Southwest Research Institute (SWRI) reported on the changes reflected in the JWST studies. Not only does Europa's surface have amorphous ice, but there's evidence of crystalline ice scattered around there. That indicates the presence of an active water source, such as the subsurface ocean. It also points toward geologic processes that affect the surface. The changes seen at Europa are very short-term, perhaps two weeks in some places. "Our data showed strong indications that what we are seeing must be sourced from the interior, perhaps from a subsurface ocean nearly 20 miles (30 kilometers) beneath Europa's thick icy shell," said Raut. "This region of fractured surface materials could point to geologic processes pushing subsurface materials up from below. When we see evidence of CO2 at the surface, we think it must have come from an ocean below the surface. The evidence for a liquid ocean underneath Europa's icy shell is mounting, which makes this so exciting as we continue to learn more." As a Galilean moon, Europa orbits near the planet and within its strong magnetic field. Thus, the surface gets bombarded by radiation. It is tidally locked, meaning it shows the same face to Jupiter as it orbits. Europa has a rocky and metallic interior, covered by an ocean and topped by an icy shell that's fairly young in geological terms. It appears to be no more than 180 million years old. That tells us it has been resurfaced from within. JWST's spectral studies of the surface show that the ice crystallizes in different ways in various places. Generally, water ice freezes into hexagonal crystals. That's what we see on Earth when it snows or when rain freezes. However, Earth's surface is largely protected from outside influences such as radiation and the ice stays in crystalline form much longer. Related: 'Previously unimaginable': James Webb telescope breaks its own record again, discovering farthest known galaxy in the universe On Europa, charged particles trapped in Jupiter's magnetic field bombard the surface. That disrupts the crystalline structure of the ice, turning it into amorphous ice. If that's all that ever happened to Europa's surface, you'd expect to see amorphous ice everywhere. Instead, the JWST spectral studies showed evidence of crystalline ice. There are also other surface "units", such as ridges and cracks. Radiation doesn't explain them, but other processes can create them. Combined with the new data collected by JWST, Raut said they are seeing increasing evidence for a liquid ocean beneath the icy surface. Scientists thought that Europa's surface was covered by a very thin (perhaps half a meter thick) layer of amorphous ice protecting crystalline ice below. The new evidence of crystalline ice on the surface also shows up in other areas, especially an area known as the Tara Regio. According to co-author Richard Cartwright of the Johns Hopkins Applied Physics Laboratory, the surface may be different than expected in places. "We think that the surface is fairly porous and warm enough in some areas to allow the ice to recrystallize rapidly," said Cartwright. "Also, in this same region, generally referred to as a chaos region, we see a lot of other unusual things, including the best evidence for sodium chloride, like table salt, probably originating from its interior ocean. We also see some of the strongest evidence for CO2 and hydrogen peroxide on Europa. The chemistry in this location is really strange and exciting." Related: How many moons does Jupiter have? The CO2 found in this area includes the most common type of carbon, with an atomic mass of 12 and containing six protons and six neutrons, as well as the rarer, heavier isotope that has an atomic mass of 13 with six protons and seven neutrons. That raises questions about the origin of the CO2. "It is hard to explain, but every road leads back to an internal origin, which is in line with other hypotheses about the origin of 12CO2 detected in Tara Regio," Cartwright said. So, how is water forced to the surface? There are two main sources of heat at work: tidal heating and radioactive decay at the core. Both of these processes warm the subsurface ocean and force water to the surface. What causes the chaotic terrain seen at Europa in such places as Tara Regio? There are several possible ways. One way is through the formation of chaos regions — those places that appear to be cracked and jumbled. They could be the result of material forcing its way via diapirs (think of them as stovepipes from below that convey warmer water and slush up to the surface). Once that water gets to the surface, it freezes rapidly into the crystalline ice JWST detected. The water also brings up dissolved CO2 and other materials. RELATED STORIES —Jupiter's moon Europa lacks oxygen, making it less hospitable for sustaining life —Jupiter's 'tormented moon' Io just unleashed the most powerful volcanic event ever seen —If alien life exists on Europa, we may find it in hydrothermal vents Another method for water delivery to the surface is through plumes. These geysers shower the surface with ice grains. Other mechanisms that could be forming crystalline ice are migration from other parts of the surface and impact exposure. Impacts are well known to "garden out" fresh ice in a short period of time. Such a collision may well explain the ice seen at Tara. This resurfacing with crystalline ice is relatively short-lived. That's because the constant bombardment of charged particles works immediately to create amorphous ice. The authors of the paper (see below) state that the charged particle-driven process that changes the ice may work in as little as 15 days on Europa's leading hemisphere. In other places, that might work faster. So, given that Europa is constantly refreshing its surface and charged particles are rapidly breaking that ice down, Europa is a busy, constantly changing place. The upcoming Europa Clipper mission should be able to study these regions in more detail during its many close passes of this tiny moon. The original version of this article was published on Universe Today.
Arab News
2 days ago
- General
- Arab News
What We Are Reading Today: ‘Becoming Earth'
Author: Ferris Jabr Published in 2024 and written by Ferris Jabr, 'Becoming Earth' talks about how the planet we know and live in started and came to life. One of the significant thoughts Jabr argues through his book is the idea that billions of years ago, life transformed from a collection of orbiting rocks into what we now know as our cosmic oasis. This process released oxygen into the atmosphere, formed seas and oceans, and shaped rocks into fertile soil. Through the book, the author also discusses various environmental systems and how they operate. He talks about the roles of microbes in shaping continents, the Amazon rainforest's self-sustaining rain cycle and the impact of human activities on planetary systems, all connected to other natural events. Surprisingly, as Jabr discusses the disadvantages of human activity leading to environmental crises, he also highlights the importance of humans in improving ecosystems. Despite the negative impacts people have had on the environment, humanity has expended a great deal of energy to understand and mitigate environmental problems, he argues. However, the book has received some criticism, with reviewers arguing that Jabr may have conflated his personal perspective on Earth with scientific research and evidence in the process of using metaphors to explain science. Other reviewers said that a few sections of 'Becoming Earth' may need improvement and more in-depth scientific evidence to support the conclusions Jabr makes.
