Burning Hot Spots, Burning Cliffs and the Ionia Volcano - geological mystery

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Burning land thermal Hot Spots and Burning Cliffs

Burning or hot land can be found in areas around the world, the earth either creates smoke or smoulders (sometimes the vegetation catches fire) but it is not generally on fire.  What causes this as there is no apparent fire underneath the surface.  With the Hot Spots in Los Padres National Forest the land is very hot just below the surface but gets cooler as you get deeper.

The UK has a number of Burning Cliffs that have been mentioned, investigated and photographed over the years.  The University of Southampton has a great article on Burning Cliffs (as Ian West of their Geology Department always does).

The smoke coming from a Hot Spot is very similar to the "Ionia Volcano" that Lewis and Clark visited in Dixon County in 1804

Are Fumaroles (cracks in the ground where steam/smoke escapes) an affect and not a cause, are they just secondary or do they help with the process?  Are these processes part of an underground fire, energy exchange or a variation of serpentinization?

Are landslides a related feature, trigger or affect?

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Ventura County hot spots - thermal geological puzzle

In seperate areas of land in Dick Smith Wilderness (Los Padres National Forest) the surface of the earth has got so hot it starts fires, melts the soles of your boots but as you go a few feet deeper the temperature falls.  A foot below the surface it can be 800 degress yet gets colder as you get deeper.

The thermal hot spots are not just located to one precise point of land, there have been at least 2 areas of Hot Spots over the years.

Are Fumaroles an affect and not a cause, are they just secondary or do they help with the process?

A discussion on natscience.com has some scientific ideas on the Hot Spots smoulderings in the Los Padres National Forest, one of the possibilities is a type of serpentinezation.

Scientists puzzle over source of county hot spots

800 degrees foot below surface then it cools down deeper you get? - What's a Hot Spot not?

High atop a steep grass-covered mountain overlooking the Little Sespe Canyon near Fillmore, the earth is on fire.

Wisps of smoke rise from a brown patch of grass that looks like it was toasted under an oven's broiler. Deep down, under the dirt, rocks and grass, something is smoldering and burning, sending smoke through cracks in the parched soil.

It's being called a natural anomaly, a geological whodunit, a scientific puzzler. And it's the second time that scientists have been scratching their heads over the fact the earth under Ventura County is burning.

In 2004, a patch of land northwest of Ojai burned so hot, it started a brush fire that scorched three acres in Los Padres National Forest. Firefighters cleared the grass from the newest area of hot earth near Fillmore on Friday so the same thing won't happen..

Though the outcome of both circumstances is the same — ground hot enough to delaminate boot soles — the reasons they started are likely very different. But both are equally fascinating to those who make their living examining rocks and sediment.

"This is a lot of fun," said Allen King, a former geologist with the U.S. Forest Service who has studied both sites. "I'm retired, but this is what I love to do."

The leading theory behind the latest hot spot is that gas or oil or some other hydrocarbon deep in the soil caught fire and is burning, pushing ground temperatures to 812 degrees. What ignited it or when it started burning is a whole other question.

"We don't know how long this particular thing has been burning," King said.

Firefighters have responded to the area five times since 1987, at times dumping water into the ground to try to quash the flames. King said a landslide hit the area within the past 100 years or so, possibly creating enough friction to start a fire. Another theory is that the land is so dry and parched that all moisture has been sapped from the ground, making it more susceptible to ignition. King said it's possible that some spark on land caused the underground blaze. How long it will burn is anyone's guess.

Such fires aren't uncommon in areas where there is a high concentration of gas or oil underground, he said.

But while the origins of this fire may be a relatively common phenomenon, the one near Ojai is still a puzzle.

"We've been researching it for a while and don't have all the answers," said Scott Minor, a U.S. Geological Survey researcher based in Denver who has made multiple trips to the site. "It's like detective work."

He and other scientists, including King, are hoping to publish a paper on their findings that may be a geologic first.

The anomaly was discovered after the land got so hot, it started a brush fire and burned three acres. Their theory is that there are high concentrations of pyrite — commonly called fool's gold — deep in the earth that were oxidized and converted to another mineral when a flush of oxygen was introduced after a landslide. The oxygen could have come from new fissures in the earth.

The process of converting to a new mineral was an exothermic reaction, releasing heat that could have sparked old carbon-based material — decayed wood or plants — that started the underground blaze.

King stuck a thermometer 14 inches into the ground and got a reading of 550 degrees. One time, the ground was so hot, the glue holding the sole of his boots melted. Grass can burn at 300 degrees.

"After that we were more cautious about standing in one place for too long," he said.

Minor said if a landslide were indeed a factor, it could be a new geologic discovery. The research group he's working with would like to drill down into the earth to see if the materials support the theory but is faced with a few hurdles. The first is funding and the second is the fact that the area is in the Dick Smith Wilderness, where no machinery is permitted.

Until then, the scientists are having fun trying to solve the puzzle.

"It's always neat when you explore something that is new and something that hasn't been documented before," Minor said. "It's fun to speculate, but it's a lot more satisfying when you can nail it down."
Scientists puzzle over source of county hot spots - ventura county star .com

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Dick Smith Wilderness Hot Spots

Fire-sparking hot spot stumps scientific team (7.11.05)

A mysterious hot spot — so hot it ignited a fire in a remote corner of Los Padres National Forest — has stumped a dozen geologists who have trekked out to study it, amazed to see something they have never seen before.

The hot spot was discovered by Los Padres fire crews last summer after a hunter reported a column of smoke hovering over the ridgelines of the Dick Smith Wilderness in the rugged San Rafael Mountains. Fire crews were flown in to extinguish the fire, which had burned through about 3 acres of chaparral and piñon trees growing on a rocky canyon landslide.

It was a sunny day in the middle of August, void of thunder or lightning. What had started the fire? As the firefighters walked around, they noticed something strange.

“They saw fissures in the ground where they could feel a lot of heat coming out,” Los Padres geologist Allen King said. “It was not characteristic of a normal fire.”

A day or two later, the fire investigators went back to the canyon, this time armed with a candy thermometer. They stuck it into one of the cracks in the landslide. It hit the top of the scale, at 400 degrees.

The crew called Mr. King, and he made the three-hour hike into the badlands to see for himself. He dangled a long plastic strip into one of the cracks. Within seconds, it melted away into nothing.

So Mr. King called in Robert Mariner, a U.S. Geological Survey hydrologist who studies volcanic gas vents at Mt. Shasta, Mt. Hood and Mt. Rainier.

“When I heard about the candy thermometer, I was amazed,” Mr. Mariner said, noting that the temperature of the volcanic vents he studies is typically 200 degrees, around the boiling point of water. “I thought these guys were pulling my leg.”

It was no joke. Since August, Mr. King, Mr. Mariner and 10 other California scientists, including Jim Boles, a mineralogist at UCSB, have backpacked out to the hot spot looking for answers, lugging heavy equipment up and down the steep mountain slopes in 100-degree heat.

The scientists stuck long wire probes into the cracks and drove pipes into the ground to measure the hot temperatures. With the help of an air reconnaissance flight and thermal infrared imaging, they found that the hot spot patchily covered three acres, most of it overlapping the fire area.

The hottest spot of all was 11 feet underground, at 584 degrees — a temperature that is hot enough to melt solder, an alloy of tin and lead. At just 4 inches down, the scientists found temperatures of up to 493 degrees. Paper and wood burn at 451 degrees.

The geologists began to joke about bringing in some tri-tip for a barbecue, instead of the granola bars and nuts they were eating. They wore hard hats and were careful where they stepped. Mr. King nearly lost the sole of one hiking boot because it came unglued on the hot rocks. He re-attached it with duct tape for the rough hike back.

The landslide itself was risky, too. It had probably occurred during El Niño rains of 1998 and was still active. New fractures recently opened around the top of the slide.

“It is still potentially dangerous to be walking on,” Mr. King said. “And we think it could be a danger again in terms of forest fire. The grasses have grown back, and there still remains a potential for reignition.”

The teams took the temperature of the hot spot in 22 locations, returning every couple of months to sample them all over again.

Surprisingly, they found that the rocks did not get significantly hotter, deeper down. During the past 10 months, the hot spot has cooled only slightly: The hottest sample has dropped from 584 degrees to 565 degrees.

Mr. Mariner visited the slide four times to study the composition of the gases coming out of the hot spot. He found carbon dioxide and carbon monoxide, the by-products of combustion.

“I keep expecting it to change suddenly, as the source of whatever we’re burning is consumed, but it’s changing slowly,” Mr. Mariner said. “We’re getting more oxygen in there.”

Gradually, the scientists started narrowing down the possible causes. They found no oil and gas deposits or vents in the vicinity and no significant deposits of coal. The Geiger counter readings were normal for radioactivity, and there was no evidence of explosions or volcanic activity. Hot springs, a sign of geothermal activity, exist elsewhere in Los Padres, but nothing like that was happening here.

One possible explanation still under study is that an earthquake fault may be the source of the heat, Mr. King said, adding, “We can’t rule out anything definitely yet.”

But the likeliest theory, though still unproven, Mr. King said, is that when the landslide occurred, the slide broke apart the rock, creating a chemical reaction between oxygen in the air and minerals in the rock.

The rock, a type of shale, contains iron sulfides called pyrite and marcasite. When they are oxidized, the scientists theorize, the sulfides give off heat, burning the organic material in the shale — the remains of dead plants and animals that were deposited into the mud on the ocean floor, 45 million years ago.

“Oxidation is combustion, but it’s burning without the flame,” said Mr. Boles, the UCSB geologist.

Perhaps it has something to do with the way the air is circulating through the landslide, he said. One thing that is puzzling, Mr. Boles said, is that there seem to be only small amounts of pyrite and marcasite in the rock.

He said that elsewhere in the world, waste piles in mining areas have been known to heat up and cause fires, but that is only where the rock contains high concentrations of sulfides.

“If we had found a coal bed in the landslide or a huge mass of marcasite or pyrite, we would have been a lot happier.”

Mr. Boles said. “But we don’t see anything obvious. It’s hard to explain.”

In August, the hot rocks ignited the roots of plants growing in the slide area, causing the forest fire. But scientists are at a loss to explain why no fires have occurred on hundreds of other shale landslides in Los Padres.

“What’s so different about this one?” Mr. Boles said. “That’s the question we keep asking, every time we go out there.”
On their last trip to the Dick Smith Wilderness, the geologists dug up some of the hot rock, let it cool for an hour and stuffed it in their backpacks to send to U.S. Geological Survey labs in Denver. There, it will be analyzed with an electron microscope.

“We’ll be able to determine whether there’s enough sulfide mineral to support our theory,” Mr. King said. “For a geologist, this is a very exciting find. We’re not aware of any other features of this nature, where a landslide has started a fire.”
Santa Barbara News Press - Los Padres National Forest Hot Spots -

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Burning Cliffs and Hot Spots in Britain

Britain has reports of Burning Cliffs similar to Hot Spots and the famous "Ionia Volcano" that Lewis and Clark visited in 1804.

Burning Cliffs of Dorset - University of Southampton - Ian West (Geology Department)

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Ionia Volcano  - Lewis and Clark 1804

Ionia Volcano

Unique sights between Omaha and Sioux City were described in the morning edition of the Omaha Daily Bee, on July 7, 1874. A letter writer, identified only as "RANGER," [the pen name of John Harwood Pierce] described a Dixon County area that had attracted the attention of Lewis and Clark in 1804 and that of later sightseers and amateur geologists.

RANGER visited what he called the "Ionia volcana," about half a mile from the village of Ionia. "Mr. S. T. Hill, who is the general business man of this portion of the country, kindly volunteered to act as guide. He took us in his skiff and rowed up the [Missouri] river to a bank towering up from the water's edge full two hundred feet. There, on a narrrow plateau about half way up the bluff, we saw and smelt the sulphurous vapor which indicated the spot we sought. On arriving at the plateau we saw several fissures in the clay, from which issued vapor so hot that the ground in the vicinity was too warm to rest the hand on comfortably. On listening, we could hear strange sounds under our feet, like the distant roar of a blast furnace.

"Mr. Hill said that it was considerably hotter than when he was there a few days before, and that the heat has been continuously increasing. Some time before this 'hot-hole' was discovered a vast land slide occurred, which is supported by the internal fires which have now found a breathing place."

RANGER also called attention to fossil finds in the area: "After examining the embryo Aetna our attention was called to the bluff, which is of slate and hard clay, with occasional gypsum formation and is full of petrifaction of all kinds. Half way up the bluff we dug out of the slate a petrified backbone, showing every veterbral [sic] and not scarred or injured in the least, and immediately along side we found imbedded in soft rock a handful of shell fish, and there is no scarcity to these petrifactions, but the bluffs is literally full of them. It was from one of these bluffs that Mr. Joseph Brewer dug out the wonderful petrified monster, which is now on its travels making a fortune for some enterprising side showman."

Part of the site of RANGER's "Ionia volcana" collapsed into the Missouri River in 1877. By 1882 historian A. T. Andreas reported that little of interest remained there.
Ionia Volcano  - Lewis and Clark 1804 - Nebraska history .org