Ammonite Fossil Extraction

 

These beautiful Ammonite fossils are found in southern Alberta, Canada, where they’ve been preserved in shale for over 70 million years. Ammonites were squid-like creatures that lived in coiled shells, and this specimen comes from the Bearpaw Formation, a geological site known for producing some of the most well-preserved Ammonites in the world.

Many of these fossils reveal a vivid layer of Ammolite, an iridescent mineral (Aragonite) that forms on the surface of the original shell. Ammolite is prized for its striking iridescent colors, ranging from red, orange, and yellow to green, blue, and occasionally purple. The colors are completely natural and result from millions of years of pressure and mineralization. Ammolite is found almost exclusively in this region and is recognized as Canada’s official gemstone. Because Ammolite is relatively soft with a Mohs hardness of 3-4, Ammolite is often stabilized with epoxy or laquer to improve its durability.

(Note: the fossil shown in the ground and the prepared specimen are not the same individual—this video illustrates the general process from discovery to preparation.)

Extraction video courtesy of @koriteammolite at the Korite Mine in southern Alberta, Canada

Earth has been hiding a fifth layer in its inner core

 

Scientists say they've detected a new, mysterious layer at the center of our home planet. The discovery could unearth more about Earth's history.

By Donna Sarkar 

One of geology's basic principles is that the Earth is made up of four layers: the crust, the mantle, the outer core, and the inner core. But this may be squashed in light of a new study that suggests Earth actually has a distinct fifth layer that's been under our feet all along.

Researchers at the Australian National University (ANU) say that the new layer they uncovered is located within Earth's inner core. Deeper analysis of this discovery could help scientists better understand our planet's history and evolution.

A peek inside Earth

Approximately 4.6 billion years ago, the Earth formed. The story starts with the planet's interior or rocky core, which formed through the collision of heavy elements. The core, found at the center of the Earth, is made up of two parts. The outer layer, comprised of liquid iron alloy, is about 1,355 miles thick. The outer core is also thought to be responsible for Earth’s magnetic field. In contrast, the inner core is made up of solid iron alloy with a radius of 760 miles.

Next comes the mantle, which sits directly above the core. This layer is composed of mostly silicate rocks that are rich in magnesium and iron. The mantle has a thickness of about 1,793 miles, making it Earth's thickest layer. The thinnest and most brittle layer is the crust, however. It varies between 18.6 to 43.5 miles in thickness and forms the outermost layer of our home planet.

Earth's layers before the discovery of the innermost-inner core. The newest layer is situated just below the inner core.

OSweetNature/Shutterstock

The fifth layer

Scientists have long suspected that Earth's inner core was made of two layers. But it wasn't until ANU researchers took a closer look at what lies below that an “innermost inner core" was confirmed.

Their work revealed a distinct change in the structure of iron deep within the inner core at about 3,604 miles below the Earth's surface. You may recall from earlier that the inner core consists of solid iron alloy. This is due to high pressure deep within the Earth that stops the iron alloy from melting. But distinct structural changes were detected in this iron alloy that set apart the newly discovered innermost layer from the rest of the inner core.

According to Salon, this discovery led the researchers to believe that the change in structure may have been caused by an unknown, dramatic event early in Earth’s history. Further examination of this tiny layer may provide additional details around how our planets formed.

“The details of this big event are still a bit of a mystery, but we've added another piece of the puzzle when it comes to our knowledge of the Earths' inner core,” said the study’s lead author and researcher, Joanne Stephenson, in a statement.

Behind the scenes of the discovery

Seismic monitoring allows us to gain a better understanding of Earth's interior. This is made possible by measuring sound waves that are created by earthquakes and pass through Earth's layers. By analyzing how the different layers cause the sound waves to slow down, scientists can catch a glimpse of what lies below.

The recent discovery was made with the aid of a special search algorithm that researchers used to compare thousands of models of the inner core with decades worth of data on how long seismic waves take to travel through Earth. This data, gathered by seismograph stations all over the world, helped detect the changes in the structure of iron in the inner core. These findings helped confirm that Earth’s inner core has another layer.

Although this work is still being analyzed, the discovery of a new layer may pave the way for a new geological principle and prompt textbooks to be rewritten.

https://bit.ly/3sMZmIs

How California Is Predicting And Preparing For The Inevitable

There’s a crack in California. It stretches for 800 miles, from the Salton Sea in the south, to Cape Mendocino in the north. It runs through vineyards and subway stations, power lines and water mains. Millions live and work alongside the crack, many passing over it (966 roads cross the line) every day. For most, it warrants hardly a thought. Yet in an instant, that crack, the San Andreas fault, could ruin lives and cripple the national economy.

In one scenario produced by the United States Geological Survey, researchers found that a big quake along the San Andreas could kill 1,800 people, injure 55,000 and wreak $200 million in damage. It could take years, nearly a decade, for California to recover.

On the bright side, during the process of building and maintaining all that infrastructure that crosses the fault, geologists have gotten an up-close and personal look at it over the past several decades, contributing to a growing and extensive body of work. While the future remains uncertain (no one can predict when an earthquake will strike) people living near the fault are better prepared than they have ever been before.

THE TROUBLE WITH FAULTS

All of the land on earth, including the ocean floors, is divided into relatively thin, brittle segments of rock that float on top of a much thicker layer of softer rock called the mantle. The largest of these segments are called tectonic plates, and roughly correspond with the continents and subcontinents of the earth.

The San Andreas fault is a boundary between two of these tectonic plates. In California, along the fault, the two plates--the Pacific plate and the North American plate--are rubbing past each other, like you might slip by someone in a crowded room. The Pacific plate is moving generally northwest, headed towards Alaska and Japan, while the North American plate heads southwest.

In a simplified, ideal world, this movement would happen easily and smoothly. Because it covers such a large area, not all of the fault moves at the same time. In the middle, things are moving rather smoothly, with part of the Pacific plate gliding by the North American plate with relative ease, a segment that scientists say is ‘creeping’.

It’s at the northern and southern extremes where things get tricky. The real problems begin when the plates get stuck, or wedged together.

VISIONS OF A DISASTER

The fear of a huge earthquake from the San Andreas devastating the west coast has been rich fodder for disaster films, including Superman and, more recently, San Andreas. The good news is that the worst-case scenarios in those films are completely impossible. California will not sink into the sea, and even the largest possible earthquake is short of anything that the Rock had to wrestle with.

But disasters have happened.

In 1906, the northern segment of the fault, near the city of San Francisco, ruptured along nearly 300 miles, causing a huge earthquake that led to fires, downed buildings, and thousands of casualties. The death toll was between 700 and 2,800.

Meanwhile, other segments of the fault, like one south of Los Angeles that hasn’t seen a large earthquake since 1690, are considered stalled. Centuries of energy are built up and ready to be released. When? Nobody knows.

Recent analyses suggest that in a worst-case scenario, the San Andreas would beget an earthquake ranking an 8.3 on the Richter scale, a logarithmic scale on which a 6.0 is ten times as powerful as a 5.0, a 7.0 ten times as powerful as a 6.0, and so forth. To put that in context, earthquakes under 2.5 are rarely felt. Earthquakes under 6.0 can cause some damage to buildings, but aren’t major events. Above that level things start to get interesting. The largest recorded quake in the United States was a 9.2 earthquake that hit Alaska in 1964.

“That would require the San Andreas to rupture wall to wall from its southern extremis to up to Cape Mendocino,” says Tom Jordan, the director of the Southern California Earthquake Center at The University of Southern California,. He explains that the creeping segment in the middle acts as a buffer, making the 8.3-magnitude earthquake much less plausible than some other options.

Even if the 8.3 earthquake never materializes, scientists worry that a rupture along the long-inactive southern segment could be devastating, compounded by the large population in the area. The 1989 Loma Prieta earthquake that shook San Francisco was only a 6.9, but it caused billions of dollars in damageinjured over 3,000 people, and killed 63.

“The San Andreas lies close to the coastline where people live,” Jordan says. The valleys along the coast that proved so enticing to the settlers who founded cities like Los Angeles are large areas of sedimentary rock that could be hugely problematic in an earthquake.

“Even though L.A. is 30 miles from the San Andreas, it can still get very strong ground motion,” Jordan says. “The sediments shake like bowls of jelly.”

But even just a medium-bad scenario could be enough to kill hundreds and ruin the economy.

Researchers like Jordan are building up huge, incredibly detailed 3D maps of the geology near the San Andreas fault. These maps can be used to generate detailed assessments for almost any possible earthquake scenario that might happen along the fault.

In 2008, United States Geological Survey scientist Lucy Jones and colleagues published the ShakeOut scenario, a detailed report that looked at what could happen if a large (magnitude 7.8) earthquake occurred along the southern leg of the fault.

Just like the 1906 earthquake in San Francisco, people living in the area would be without power and water for interminable lengths of time, and in the immediate aftermath, firefighters would not have access to water to fight the fires that would spring up in the wake of the disaster. And in California’s current drought, the fires after the earthquake could prove more devastating than the shaking itself.

DODGING A BULLET

Scientists may not be able to predict where and when a strike will hit, but the more they understand what could happen, the more they can help plan for any event. Last winter, Los Angeles Mayor Eric Garcetti announced a plan called Resilience By Design, that tries to address the huge risk facing the city if there was an earthquake along the San Andreas.

“It is highly unlikely we’ll make a century [without a large earthquake]” said Jones, who also headed up the Resilience by Design group. Reinforcing the city’s lifelines, like roads and utilities, is a huge priority.

Fortunately, California has a precedent to the north.

In 2002, the Denali fault in Alaska slipped and caused an earthquake with a magnitude of 7.9, the largest inland earthquake recorded in the country in 150 years. And running right across that fault was the Trans-Alaska Pipeline, an 800-mile long piece of infrastructure that carries 550,000 barrels of crude across near-pristine tundra every day.

“It was the biggest ecological disaster that never happened.” Jones said.

The pipeline was built to accommodate the movement of the earth, so that even though the earth slid by up to 18 feet in the 2002 earthquake, the pipeline didn’t break, averting a serious oil spill. To avoid rupturing, the engineers designed the above-ground portion of the pipeline in an intentional zig-zag pattern instead of a straight line, giving the pipeline flexibility. The pipeline itself can also slide. Instead of being anchored in the permafrost, part of the pipeline sit on Teflon-coated ‘shoes’ which rest on huge steel beams that sit perpendicular to the pipeline. In the event of shaking, segments of the pipe can slide on the beams like train cars on rails, without breaking.

DENALI PIPELINE

The zig-zag pattern allows it to flex and move without breaking

THE NEXT QUAKE

In California, water pipes and electrical lines could be built or retrofitted with similar flexibility. Researchers are even working on building earthquake-resistant houses that can slide back and forth on instead of crumbling. Unlike traditional homes, which sit on a foundation, these earthquake-resistant homes sit on sliders made out of steel, that, just like the Trans-Alaska Pipeline, can slide over the shaking ground instead of breaking.

The internet of everything has a role to play here too. In the future, networks of devices scattered across the southern California landscape could monitor an earthquake as it starts. This seismic network could send out an alert as the earthquake propagates through the earth, giving utilities precious seconds of warning to shut off valves in pipes along the fault, shut off power to prevent damage, and even send an alert to operating rooms, allowing a surgeon to remove her scalpel from a patient before the shaking even begins.

Scientists already have a seismic network in California, but more seismic sensors and technical development are needed to get the fledgling network to the next level. Unfortunately, those developments require money, and getting enough funding to build the next system has been elusive.

The cost for a truly robust alert system is estimated at $80 million for California alone, and $120 million for the whole West Coast. But funding is sparse. Earlier this year, President Obama pledged $5 million. The first sensors are already being used by San Francisco's mass transit system to slow down trains in the event of an earthquake.

To see what the future of California might look like, one only has to glance west towards Japan, where even their fastest trains come to a halt at the first sign of an earthquake, elevators allow people to disembark, and people get warnings on radio, TV, and cell phones.

Similar techniques could be employed near Los Angeles, Jones says, making the city ready to bounce back from even the worst earthquake that the San Andreas can throw at the city.

Ralph Waldo Emerson once said that “we learn geology the morning after the earthquake.” Fortunately for Los Angeles, plenty of people, from geologists to city and emergency planners, have no intention of waiting that long.

by Mary Beth Griggs

How 11 Legendary Outdoor Destinations Formed

Hardcore adventurers will really go the distance in order to ski, surf, swim, or soar in Earth’s most incredible landscapes, but the places themselves have come a long way, too—here’s a few examples of some of their most radical geologic journeys. 

1.BADLANDS NATIONAL PARK // SOUTH DAKOTA

The gorgeous views one can enjoy walking the many hiking trails in Badlands National Park were formed by a pair of simple processes: deposition and erosion. First, many layers of sedimentary rock began to form some 75 million years ago, and continued to pile up with everything from volcanic ash to alligator fossils. Then, about 500,000 years ago, the Cheyenne River brought waterways flowing from the nearby Black Hills into the Badlands and began to carve away at the rock, creating the incredible landform we see today. It’s estimated that in another 500,000 years, the process will be complete, and the Badlands will have been completely chipped away.

2. ULUWATU BEACH // BALI 

Located on the southwestern side of the Bukit Peninsula, this famed beach is one of the best-known surf destinations in the world. It’s surrounded by limestone cliffs that were formed as a result of the subduction of the Indo-Australian Plate under the Eurasian Plate (or possibly the Australian plate under the Sunda plate), bringing it above sea level. The imposing cliffs looming over the surf mean that this isn’t just one of the best places to catch a wave, it’s also one of the most beautiful. 

3.  DEVILS TOWER NATIONAL MONUMENT // WYOMING

Devils Tower is one of the go-to destinations in the world for serious rock climbers, but it’s also a geological formation worth simply marveling at. The rock rises up 1,267 feet above the Belle Fourche River, and began its formation over 200 million years ago. The oldest sediment was laid when the area was covered in a shallow sea, and more layers continued to form as bodies of water came and went. The tower itself was formed from magma: About 50 million years ago, molten rock pushed toward the earth’s surface and forced its way into the sedimentary rock layers. Geologists don’t agree on exactly what occurred beyond the introduction of igneous material, but it’s likely that magma simply cooled, crystallized, and contracted while hardening to form the hexagonal columns. After many years of erosion, the soft sedimentary rocks disappeared, leaving behind the much sturdier igneous rock that makes up Devils Tower. And as time goes by, more and more of this amazing feature will be exposed at the surface until it too erodes away. 

4. THE GALAPAGOS ISLANDS // ECUADOR 

This archipelago of 13 major islands is still being formed to this day, and as a whole, is considered relatively young in geologic terms: The oldest existing island is around five million years old and the youngest is around 700,000 years old. The chain is formed from hotspot volcanism; the Nazca tectonic plate is moving over a hot area of the mantle, and so it continuously forms volcanoes that rise to the surface and create new islands. And once the new island has moved past the hotspot, the process starts all over again and a new island forms. Truly a dynamic landscape, about 50 eruptions have occurred there in the last 200 years. It’s those eruptions that give the islands their conical shape.

5. THE ALPS

Best known for skiing, the Alps are also a famed destination for mountain bikers who hit the trails on wheels instead of skis. The awesome (in the truest sense of the word) mountains are part of an orogenic belt of mountain chains that runs through Europe and Asia. The African and Eurasian tectonic plates collided, causing sediment in the ancient Tethys Ocean to get pushed up. Later on during the Ice Age, glaciers traveled down the valleys, carving out space along the way, then created the alpine lakes as they melted. We imagine the skiing would have been really spectacular then.  

6. THE SOUTHERN ALPS

The other Alps live across the equator and make for another epic skiing site. Geologically speaking, the Southern Alps are young—only about five million years old, and are still in the process of changing. Similar to their northern brethren, the Southern Alps are a result of tectonic plate action, this time at the Pacific and Australian plates. The mountains continue to rise as the plates collide and push up the land; in some areas, they’ve risen as much as 65,000 feet in the last three million years. As they rise, high rainfall and glaciers, which sculpted valleys and filled them up (along with large deposits of rock and debris) as they melted, caused erosion.

7. MAMMOTH CAVE // KENTUCKY

For those who want to adventure underground, there’s Mammoth Cave—a system of subterranean tunnels, the oldest of which formed around 10 million years ago. Rewind back even further to about 325 million years ago, and you’d see a massive sea that covered much of what is now the heartland of the United States. This sea deposited 600 feet of limestone over the area, and eventually it was covered by sturdier sandstone and shale. After millions of years of erosion, the soft limestone began to peek through the covering layer, and rainwater did the rest to hollow out the cave. 

8. FUTALEUFU RIVER // CHILE

For the best white water rafting in South America (or arguably the world), brave souls venture to the Futaleufú in Northern Patagonia. Much of the region was shaped by glaciers that worked the terrain over the last 800,000 years, forming the Andean lakes and many of the area’s high-octane rivers. The gorgeous blue waters of Futaleufú are the result of glacier runoff, and are part of a vast system of waterways, fed by waters from Argentina and flowing out (eventually) into the Pacific Ocean.

9.  GLACIER BAY // ALASKA

We’ve touched on a few “new” geographical features, but Alaska’s Glacier Bay is like a brand new baby in comparison to those other guys. The magnificent kayaking and sightseeing spot wasn’t even there when Captain George Vancouver toured the coast in 1794 because it was underneath a sheet of glacial ice. Since then, it’s retreated 65 miles, creating a new bay and revealing new swaths of land. The bay is also where the American and Pacific tectonic plates have been colliding for over 100 million years. This impact has led to accumulation of “terranes,” which are fragments of crustal material. It’s one of the most dynamic areas on the planet, resulting in breathtaking landscapes that literally change every single day (though at a rate you won’t be able to spot with the naked eye).

10. ARCHES NATIONAL PARK  // UTAH

This area is a treasured spot for bikers, hikers, climbers, and campers, and it’s all thanks to a series of geological process hundreds of millions of years in the making. Rock layers began forming around 300 million years ago when Utah was covered in an ancient sea. Water levels rose and fell in a cycle for years, leaving massive salt deposits that, under great pressure, rose up into a dome and became the basis for the unique rock features in the area. Later on, sandstone deposits and sand dunes formed, then mudflats, which continued to see the oceans flood and recede, all before the area became a desert, with cliffs carved out from wind and ice erosion. Sediment continued to deposit and erode (which by now, you can see is a common origin story), and today, the terrain is still quite fragile despite its imposing grandeur.

11. ARENAL VOLCANO // COSTA RICA

Costa Rica kind of hit the geological jackpot. It has the Caribbean Sea to the east and the North Pacific Ocean to the west and about 800 miles of coastline, with rain forests, coastal plains, and rugged mountains. It also happens to be the site of subduction of the Cocos tectonic plate under the Caribbean Plate, which has resulted in a chain of mountains that includes Arenal Volcano. There, you can zip line for two miles through the jungle, over a lake, and swoop by the volcano for a quick hello. It last erupted in 2010, and is still active, though constant monitoring means you won’t even see lava as you glide by.

You don’t need to explore volcanoes in Costa Rica or ski the Alps to make your next getaway one to remember. Built for the endless weekend, the all-new Toyota Tacoma will make every trip feel legendary. Learn more at toyota.com/tacoma

All images courtesy of iStock 

Year in review: Pacific Plate slides over slick layer

SHAKY GROUND  Researchers drag sensors across the ocean near New Zealand to study ocean floor vibrations, adding data to the debate about how the Earth moves deep underground.

Mantle might not drive movements after all

BY 

THOMAS SUMNER

With 6,000 kilograms of dynamite and an ear to the ground, a team of geologists shook the understanding of plate tectonics this year.
Ricocheting vibrations from the dynamite blasts, intentionally set off over two nights in New Zealand, gave geologists their first clear glimpse of the underside of a tectonic plate. The work revealed an underlying layer of partially melted rock, 100 kilometers belowground and 10 kilometers thick, that lubricates the motion of the Pacific Plate (SN: 3/7/15, p. 6).
The finding is “remarkable,” says geophysicist Simon Klemperer of Stanford University. “Explaining how these plates move is one of the things that held back the identification of plate tectonics for 50 years.”
The layer contains an estimated 2 percent molten rock, enough  to drastically reduce the strength of the rock and essentially grease the overlying plate, like a layer of melted water beneath an ice skater’s blades. Because it is sandwiched between the plate and the mantle, the layer also forms a barrier between the two. That separation challenges the prevailing view that flowing material in the mantle drives plate tectonics, says the geophysicist who led the study, Tim Stern of Victoria University of Wellington in New Zealand. Instead, forces at the edges of tectonic plates, such as the pull of a sinking plate, probably move the rocky slabs across Earth’s surface.
Such a sideways yank is what broke apart the Pangaea supercontinent around 200 million years ago, earth scientist Fraser Keppie of Nova Scotia’s Department of Energy in Halifax proposed in February (SN: 4/4/15, p. 13). Previous explanations held that a rising plume of magma from the mantle wedged the supercontinent apart. Instead, Keppie contends, as the ancient forerunner to the Indian Ocean shrank, Pangaea was pulled from two sides, ripping the continent apart between Africa and North America.
A separate team cruising across the Atlantic Ocean in March and April fired air guns that sent vibrations downward through the seawater and into the ocean crust. That work should reveal whether slick layers are ubiquitous beneath tectonic plates, and further explain how the Earth moves under our feet.

GLIDING AWAY Partially melted rock (red) appears to separate the Pacific Plate from the mantle below, reducing the force required for the massive plate to slide. Researchers are now looking for similar layers beneath other tectonic plates.

T. STERN, ADAPTED BY E. OTWELL