Researchers determine origin of mysterious stone columns along Crowley Lake

A mystery in stone

Robin Wham photographs the columns, which for decades were regarded as little more than curiosities along the eastern shore of the Los Angeles Department of Water and Power's Crowley Lake reservoir. They had been buried and hidden for eons until the reservoir's pounding waves began carving out the softer material at the base of cliffs of pumice and ash. (Brian van der Brug / Los Angeles Times)

by Louis Sahagun
Los Angeles Times

Mammoth Lakes, CA -- The strange pillar-like formation emerged after Crowley Lake reservoir was completed in 1941: stone columns up to 20 feet tall connected by high arches, as if part of an ancient Moorish temple.

They had been buried and hidden for eons until the reservoir's pounding waves began carving out the softer material at the base of cliffs of pumice and ash.

In the ensuing decades, the columns were regarded as little more than curiosities along the eastern shore of the Los Angeles Department of Water and Power reservoir, which is best known as a trout fishing hot spot about 10 miles south of Mammoth Lakes.

But now answers are emerging from a study at UC Berkeley. Researchers have determined that the columns were created by cold water percolating down into — and steam rising up out of — hot volcanic ash spewed by a cataclysmic explosion 760,000 years ago

"These columns are spectacular products of a natural experiment in the physics of hydrothermal convection," Noah Randolph-Flagg, 25, a PhD candidate and lead author of the study, said in an interview.

The blast, 2,000 times larger than the 1980 eruption of Mt. St. Helens, created the Long Valley Caldera, a massive 10-by-2-mile sink that includes the Mammoth Lakes area. It also covered much of the eastern Sierra Nevada range with a coarse volcanic tuff, or ash fall.

Randolph-Flagg said researchers not only discovered the origin of the columns but also learned a great deal about the surrounding landscape. "They have lot to tell us about what the region was like before and after the caldera exploded, and about how volcanoes can change local climate," he said.

The columns began forming as snowmelt seeped into the still hot tuff. The water boiled, creating "evenly spaced convection cells similar to heat pipes," according to the study to be presented next month in San Francisco at an American Geophysical Union meeting, the world's largest conference in geophysical sciences.

From the very first moment I laid eyes on this weird and wondrous place a year ago, I was smitten. It made me go back to school to get a master's degree in geology.
- Robin Wham, 62, a graduate student at Cal State Sacramento

Analyses by X-rays and electronic microscopes of samples of the columns found that tiny spaces in these convection pipes were cemented into place by erosion-resistant minerals.

Randolph-Flagg estimates that as many as 5,000 columns exist within a 2- to 3-square-mile area east of the lake. They appear in clusters, and are diverse in size and shape.

Many are gray, straight as telephone poles and encircled with horizontal cracks about 12 inches apart. Some are reddish-orange in color. Some are bent, or all tilting at the same angle. Still others are half-buried and resemble the fossilized backbones of dinosaurs.

Next year, the Department of Water and Power will begin ferrying students to the site as part of an "effort to further educate the public about these invaluable natural resources," said Amanda Parsons, a spokeswoman for the utility.

Edward W. Hildreth, a research geologist with the U.S. Geological Survey and expert on the history of the Long Valley Caldera and the chemistry of its tuff, welcomes the sudden interest in the columns, which can be reached by boat, on foot or by four-wheel-drive vehicles.

More analysis could help scientists better understand how quickly the columns solidified, and the chemistry and temperatures that produced their spacing, width, height and composition.

Among other researchers investigating the columns is Robin Wham, 62, a graduate student in geology at Cal State Sacramento whose proposed thesis involves mapping their precise locations and comparing their characteristics to those of similar formations in New Mexico and Mexico.

On a recent Sunday, Wham, a retired physical therapist, clambered down a steep trail with a clipboard and GPS device to double-check the coordinates of a grotto filled with columns that she likes to call "my office."

"From the very first moment I laid eyes on this weird and wondrous place a year ago, I was smitten," she said. "It made me go back to school to get a master's degree in geology."

How old is the Grand Canyon? Scientific debate rages on

View of the Grand Canyon, Arizona. There's no consensus on how old the canyon is. (Gabriel Bouys / AFP / Getty Images)

Becky Oskin LiveScience
NBC News

The Colorado River took the easy route when it carved the Grand Canyon through Arizona's ruddy sandstones and pastel limestones, a new study claims.

Instead of slicing through thousands of feet of unblemished rock, the Colorado River recycled ancient canyons, at least one of which was 70 million years old, researchers reported Sunday (Jan. 26) in the journal Nature Geoscience.

"I think the Colorado River found low places and paleocanyons and ancient topographies that led to the Grand Canyon," said Karl Karlstrom, lead study author and a geologist at the University of New Mexico in Albuquerque.

The new findings, which rely mainly on reinterpretations of other scientists' work, summarize decades of geologic sleuthing. But the study may do little to resolve the heated debate over the age of the Grand Canyon. For the past year, Karlstrom and others have stridently attacked work published Nov. 29, 2012, in the journal Science that suggested the westernmost Grand Canyon was 70 million years old.

But the debate over the Grand Canyon's age has raged for decades, in part because so much of the canyon's history is missing, carried away by the river. The little that's left means many things to many people. The argument also hinges on how one defines the Grand Canyon. Is there a Grand Canyon without the Colorado River running through it? [Video: Virtual Tour of Grand Canyon]

For Karlstrom, the answer is no. Even though his latest findings jibe with the 2012 Science paper, and he reuses that data, he asserts that the Grand Canyon is less than 6 million years old. He was also affronted by claims that dinosaurs walked on the Grand Canyon. "The Colorado River found a path and carved the entire canyon 5 [million] to 6 million years ago," Karlstrom told LiveScience's OurAmazingPlanet. "I agree our data is not in disagreement, but I had the [National] Park Service call me up and say, 'Is it true that the park is 70 million years old?'"

Assembling the canyon

To prove the point, Karlstrom and his co-authors assembled published geologic evidence, along with four new "cooling ages" in the westernmost canyon. The cooling ages come from apatite crystals, which contain helium-producing uranium. When the apatite is hotter than about 122 degrees Fahrenheit (50 degrees Celsius), helium escapes. As the rocks cool — for instance, when a canyon-carving river removes their cover — the helium stays trapped in the apatite crystals. Measuring the helium is a gauge for how long the rock has been cool, and exposed near the surface.

Karlstrom's group snipped the Grand Canyon into pieces, and then calculated how long ago each segment was carved. Only two of the segments are less than 6 million years old, the age posted on the National Park Service's signage, they found. Here's the breakdown, from east to west:

• Marble Canyon — Less than 6 million years old
• Eastern Grand Canyon — A 4,900-foot (1,500 meter) deep canyon carved 25 million years ago along the Kaibab Uplift.
• Hurricane Canyon — Carved to half its current depth 70 million years ago, flowing north along the Hurricane Fault.
• Westernmost Grand Canyon — Less than 6 million years old

The 2012 Science study also found a segment between the Hurricane Canyon and the westernmost Grand Canyon was cut to near-modern canyon depths about 70 million years ago.

Rebecca Flowers, lead author of the Science study, said she was interested to see the unusually young ages for the westernmost Grand Canyon, close to where both her group and Karlstrom's team had discovered 70-million-year-old cooling ages.

"Given the consistency of our combined helium data sets and the reproducibility of those results throughout this 35-mile [55 kilometers] section of the westernmost canyon, it will take a bit more time to understand fully why their interpretations are so different from ours and why they conclude that the erosion history varied so dramatically within this short reach of the canyon," Flowers, a geochemist at the University of Colorado, Boulder, said in an email interview.

Why is it there?

The Colorado River first emerged from the Rocky Mountains some 11 million years ago, according to old river gravels. So another huge puzzle remains: Where did the river flow before the Grand Canyon formed, and why did it finally end up in the Grand Canyon?

"To me, the greatest remaining mystery is how this got connected into a canyon," said Joel Pederson, a geomorphologist at the University of Utah, who was not involved in the study.

For now, here's Karlstrom's big picture: About 6 million years ago, something prompted the Colorado River to shift gears and head southwest. That event could have been a lake flood, climate change or subtle shift prompted by erosion. Whatever happened, the Colorado River grabbed its chance, cutting through the ancient rocks lining the gorge (up to 1.8 billion years old at the bottom) and bursting through to the Gulf of California.

Pederson agrees that Karlstrom's reanalysis won't resolve the Grand Canyon age debate, especially because geochemists can continue to debate how the cooling ages are interpreted.

"You have two groups of people who can take the same samples from the same results and come to really different conclusions," Pederson told LiveScience's OurAmazingPlanet. "That's the key battle."

But while the arguments will continue to play out in scientific journals and conferences, the big picture is getting clearer.

Long before anyone ever measured helium in apatite, geologists had discovered the Grand Canyon's ancestors, the paleocanyons that came before today's stunning vermillion walls were breached. First discovered in the 1950s, the history of these older canyons is now being refined and revised by scientists like Flowers and Karlstrom, with modern geochemical techniques.

"We now know there are parts of the Grand Canyon that are using ancient paleocanyons to a greater extent than we previously thought," Pederson said.

And geologists continue more old-fashioned detective work, tramping across the desert plateau in search of undiscovered clues about the Colorado River's history.

"There are a lot of ideas out there, but I don't think we're all in agreement yet," Karlstrom said.

California metal mine regains luster

Fears of a shortage of rare-earth minerals used in high-tech applications has bolstered an effort to reopen production at the Mountain Pass Mine in the Mojave Desert.

The pond that fills the bottom of the Mountain Pass rare-earth metal mine reflects the terraces. Digging is expected to resume by the second half of 2011 after the water is pumped out. (Don Bartletti / Los Angeles Times)

By Martin Zimmerman
Los Angeles Times

Reporting from Mountain Pass, Calif. - Fear of a shortage of rare-earth metals used in high-tech military and industrial products has spawned global efforts to reopen abandoned mines, including the formidable Mountain Pass Mine in California's Mojave Desert.

Discovered in the 1940s by uranium prospectors, Mountain Pass contains an array of rare earths, including cerium and lanthanum, in concentrations almost double those found at the world's biggest rare-earth mine, China's Bayan Obo.

"You're looking at the greatest rare-earth deposit in the world," says operations manager John Benfield as he ushers a visitor around the 2,200-acre site 60 miles southwest of Las Vegas.

Benfield's employer, Molycorp Minerals in Colorado, has just begun a two-year effort to restore Mountain Pass to its former role as a leading global producer. Those plans were given a boost recently amid fears that China was poised to ban exports of some of the scarcer rare-earth metals and to sharply limit shipments of others.

Although the Chinese government has sought to allay those concerns, a possible ban served as a reminder that the Asian nation is nearly the sole source worldwide for rare-earth metals and is likely to remain so for at least the next two years.

"You always want multiple sources for your raw materials," said Jim Hedrick, commodity specialist with the U.S. Geological Survey. "There could be a natural disaster that significantly disrupts the supply, or there could be geopolitical issues. . . . All it takes is for one person to antagonize another."

The reopening of the mine and related processing facilities would create about 900 jobs at Mountain Pass -- about 100 people work there now -- and provide U.S. companies with a reliable source for many key rare-earth metals.

These minerals, such as samarium and neodymium, are prized for chemical properties that make them indispensable in a variety of industrial and military uses including polishing glass, oil refining and manufacturing missile guidance systems.

They also play a crucial role in the development of "green" technologies such as hybrid cars, wind turbines and compact fluorescent lightbulbs. Heat-resistant magnets made with rare-earth alloys are key components of the electric motor in the Toyota Prius, for example. And lanthanum, one of the most abundant rare earths found at Mountain Pass, is used to make the car's nickel-metal hydride battery.

Mining operations ceased at Mountain Pass in 2002 amid environmental concerns and cut-rate competition from China, though processing of previously dug ore continues.

On a recent Friday, as the weekend traffic flowed on Interstate 15 toward Las Vegas and the temperature hovered around 110, the ore processing facilities hummed with activity. But the crushing mill and the conveyors that fed it with rock from the mine were silent.

The mine itself is about 1,500 feet across -- impressive to the uninitiated but smallish compared with the mile-wide behemoths around the globe where copper, gold and other minerals are excavated.

There's no giant earthmoving equipment rumbling about. Most of it was sold off when the mine was shut down. A small pump floats on the surface of the brackish green water 300 feet below. The only other signs of life in the pit are red-tailed hawks circling the mine's terraced sides in search of lunch.

Molycorp hopes to generate big profit at Mountain Pass by building an integrated manufacturing chain that starts with raw ore and ends with finished products ready for market.

"We don't want to be just a supplier of basic materials to other industries," said Benfield, the operations chief. "We want to develop our own technologies so we can determine our own destiny rather than rely on others. We're not just a mine."

The U.S. was once the world leader in rare-earth metal production. But low-cost competition from China has given that nation a near monopoly on rare-earth exports. In addition, China is becoming a key producer of rare-earth magnets.

That worries some analysts who fret that China could dominate the market for next-generation clean-energy technology in much the same way that a handful of oil-rich nations now control the bulk of world oil supplies. The fact that China and the U.S. are currently engaged in a trade tiff over tire imports hasn't soothed matters.

"They've been reducing exports of rare-earth metals for years," commodities analyst Jack Lifton said. "A few years ago, they exported 50% of their production. Now they're down to 25%. They could be down to zero by 2015 because their own demand is going up."

Rare-earth anxiety has spurred a global hunt for the minerals and is bringing back into production mining operations that have been closed for years, such as Mountain Pass.

Toyota Motor Corp. and other big users of rare-earth metals, such as Hitachi Ltd., are exploring ways to reduce their dependence on Chinese exports. They're using smaller amounts of rare-earth metals, recycling more, testing alternative materials and looking for new sources of supply.

Most of the rare-earth metals aren't all that rare. "Almost any rock you pick up has rare-earth elements in it," noted Thomas Monecke, a geology professor at the Colorado School of Mines.

The most common, cerium, is more plentiful than copper. The two rarest, thulium and lutetium, are 200 times more common than gold.

But unlike coal, iron and other industrially useful minerals, they are difficult to separate and can be mined profitably only when found in dense concentrations, such as at China's Bayan Obo mine and in clay deposits in that country's southern region.

The only other place on earth known to harbor such dense concentrations is Mountain Pass.

Molycorp, a former Chevron Corp. subsidiary, was sold to a group of private equity investors last year. Chevron had acquired the mine when it bought Unocal Corp. in 2005 and is still responsible for cleaning up some wastewater spills from past operations.

The mine's new owners are in the midst of an ambitious plan to pump out the millions of gallons of water at the bottom of the open-pit mine and resume mining by the second half of 2011.

Once ore is again coming out of the ground, Molycorp wants to install advanced extraction processes that will enable the company to achieve purities as high as those found in Chinese rare-earth metals but at a lower cost. They are also looking for joint venture partners to begin producing their own rare-earth magnets.

It will cost $100 million to $400 million to make that plan a reality. Molycorp Chief Executive Mark Smith said the company was exploring a variety of financing options including issuing debt or selling stock.

He also would consider investments from foreign investors, including Chinese.

The goal is to achieve a production rate of 20,000 tons of rare-earth products a year by January 2012, Smith said. That would meet about 20% of global rare-earth demand, based on last year's total worldwide production of around 124,000 tons, he said.

While Mountain Pass prepares to restart mining operations, mining companies are pushing to develop other known rare-earth deposits, such as those in Canada, Brazil and Australia.

The Chinese also are hunting for overseas sources, though worries about the country's control of world supplies is hampering those efforts. A Chinese mining company recently pulled out of a deal to expand its ownership stake in Australian rare-earth miner Lynas Corp. after the Australian government protested.

Although efforts to diversify the world's sources of rare-earth metals are welcomed in many quarters, Lifton notes that, as at Mountain Pass, these new locations won't become significant producers overnight.

"Until then," he said, "we'll just have to tiptoe through the Chinese tulips."

Gold diggers

Members of High Desert mining groups head into the Mojave for fun, relaxation, and perhaps treasure


Hugh Kidd, left, sifts dirt over a gasoline-powered dry washer as Guy Praster, right, looks for another shovelful during a gold prospecting trip in March near Barstow.

TERE DARNELL KIDD
Victor Valley Daily Press

Huell Howser may be looking for California’s gold, but Norm Corey knows where to find it.

Corey has two claims in the High Desert, and both lie miles and miles down obscure dirt roads.

There are other claims he can work, though. His club, the Valley Prospectors, has claims that can be worked by anyone in the club. As far as we know, there have been no six-shooters drawn to defend a claim nor to steal one.

Mining is a bit more friendly nowadays. Mining clubs work claims together, and for the most part, just have a good time.

Corey, like most other miners, sees mining as an exciting way to relax. Although that sounds like an oxymoron, most prospectors will tell you it’s the best way they know to while away their time and get back to Mother Nature.

He and companion Eleanor Praster brought her grandson, Guy Praster out to work a claim on a recent Saturday. It was his first time out and it was something he wanted to do before joining the Marines.

Corey obviously enjoys mining. It doesn’t bother him a bit that it takes about 125 shovels of dirt — thrown into a machine that shakes out the dust, large pebbles, and other particles — to come up with enough dirt to start panning.

Of course, on this particular Saturday, he has Praster’s grandson along to do a lot of the digging while he supervises.

Corey, donning a rugged looking slouch hat with a wide rattlesnake band around it (one he killed and skinned himself), has a fairly wry sense of humor.

When he tells you that you can find gold using a dowsing (divining) rod, you don’t know if he is joking or not.

He is backed up by another prospector named Barstow Bob — a tall dark man with a white beard and handsome features — who says you can find anything you want with the dowsing rod.

He says if you’re looking for water, all you have to do is think water — let yourself become water — and the rod will find it for you.

“If you’re looking for gold and think gold, the rod will find it for you,” says Bob.

There is a certain wildflower, found in the sparse vegetation of the area, protruding from the dirt and pebbles. The stem is rotund and hollow, topped with tiny purple flowers. No one seems to know the name of the plant, but some prospectors believe that wherever they find it, gold is close by.

Gold miners are like Las Vegas gamblers. They have their own superstitions regarding where and how to find gold.

Instead of rolling dice after blowing a warm breath upon them or even feeding slot machines with quarters after some kind of ritual, miners look for signs that tell them where to dig.

Most gold miners seem to have an air of rugged individualism. They like being out in remote areas that lay at the end of bumpy dirt roads, and they don’t mind getting dirty. They enjoy the quest about as much as actually finding the gold. They just have a really good time.

There are differing ways of mining. There is dry wash, and there is wet wash, and many use metal detectors. So while most miners enjoy getting back to nature, some are incorporating technology in their searches.

The General Mining Act of 1872 made it legal for anyone 18 years or older to locate and mine a claim on Federal land. Before this, the laws governing mining were made up by miners as claims were established and word spread that California was rich in gold deposits. Newly acquired through the Treaty of Guadalupe Hidalgo in 1849, California had no real laws except those made up in mining camps.

The HBO series “Deadwood” portrayed the development of such a lawless mining camp. It showed how the town created its own laws out of a necessity to bring order to the camp, and more importantly to protect claims. If you have viewed any of the scenes from this program, you know the language was pretty strong, but “Deadwood” gives a fairly accurate portrayal of the development of mining towns.

Ted Sparks, a retired geologist who works part time at Mining and More, a mining outfitting store in Hesperia, says, “It is important to know the geology of the area in which you are working.”

“I hate to burst somebody’s bubble,” Sparks adds, “People come in with what they think is gold, and I have to tell them it’s not.”

Sparks says that chances of getting rich are slim, but he remembers a couple of guys who came out with 16 troy pounds of gold. There are 12 troy ounces in a troy pound. On April 7, an ounce of gold was selling for around $924 per ounce, while silver was going for about $18 per ounce.

“I want a way of life that is not constrained,” says Sparks. “I don’t want to listen to my neighbors’ dog barking. Whether I find three specks or an ounce, (the fun) is being with people you enjoy.”

Hugo Mietzner says he has over $10,000 in equipment. He is one of the miners who sees the government as encroaching on public land, making it harder for miners to use the land as they see fit.

Although Mietzner has quite an investment, you don’t need to spend a lot to get started. Norm Corey has about $800 tied up in his generator and about $400 in the dry washer.

However, all of the local clubs urge newcomers to join and go out with someone who has equipment before investing any money.

The Au Mojave Prospectors of Hesperia meet the 3rd Thursday of the month at Los Domingo’s restaurant at 15885 Main St. in Hesperia. The meetings begin at 7 p.m. The club welcomes anyone interested in prospecting. For more information, you can call Hugo Mietzner at 524-1822.

The High Desert Gold Diggers meets the second Tuesday of the month at Church of the Valley in Apple Valley at 20700 Standing Rock Road. Their Web site is www.hidesertgolddiggers.org

Our Desert Home - Cima Dome

BUD LORKOWSKI

Special to the Press Dispatch
Victorville Daily Press

Photo from Back Roads West


From the rest stop on Interstate 15 near Cima Road in eastern San Bernardino County, a gently sloping mountain can be seen to the south. It is covered by Joshua trees. Outcrops of granite rocks stand tall near its summit.

This is the Cima Dome.

There are a half dozen of these features in the Mojave Desert, known to geologists as domes. They are rare.

Domes are large features covering a hundred or more square miles in area. The Cima Dome is perhaps the easiest to recognize. The best views of the dome are from the crests of the Mid Hills, which are to the south; Cima Road traverses Cima Dome between Interstate 15 and the post office at Cima.

Topographic maps show circular contour lines on the dome. If you put a pencil under a sheet and align the pencil until it is straight up, you will create a model of a dome.

Looking down on your model you should be able to observe that the lines of equal elevation, or contour lines as they are called, are circular. The top of the dome comes to a point, like an upside-down cone.

To understand how Cima Dome was formed, you have to understand a little about the history of the crust of the Earth in the Mojave Desert.

The Mojave Desert has been subject to a lot of pushing and pulling by tectonic forces in the last few million years. First the crust was stretched and thinned by the same forces that formed the Basin and Range Region of Eastern California, Nevada and Utah.

The thin crust of the Mojave Desert was then subjected to compression by forces placed on it when the Baja California micro-plate collided with North America. When these forces squeezed the thin crust of the Mojave Desert, hot plastic material from beneath the crust, known as the mantle, was pushed up to form the dome.

The Cima Dome has a thin crust and there is a bulge of mantle material beneath the crust. Some of this mantle material found its way through fractures and faults to form the 31 or more volcanoes of the Cima Volcanic Field, on the western flanks of the dome.

On your next trip to Vegas, spend some time at the rest stop between Cima Road on Interstate 15 and look at Cima Dome. Think about what is under your feet in the crust and mantle. This should help you understand some of the forces that are constantly changing “Our Desert Home.”

Bud Lorkowski is a retired science teacher. He is currently doing a geologic study in the Mojave National Preserve for the National Park Service. He has recently completed a geological study of Hagerman Fossil Beds National Monument in Idaho.