Earth news

Yet Another Big Asteroid Strike Found In California

Elaine Meinel Supkis

Today, geologists find yet another major meteorite/asteroid strike. We can see from the moon and other planets that these events happen all the time. I will suggest all the sudden evolutionary changes that punctuate the fossil record may all be caused by celestial objects suddenly changing the ecosystem too fast for many creatures to easily evolve to accomodate these changes.

The latest one is in the Central Valley of California, buried deep in the earth by layers of silt and sediment.

By Paul Rincon
Science reporter, BBC News, Houston

A seismic survey peels away the sediments to reveal the structure
Oil exploration work in California's Central Valley region has uncovered a possible space impact crater.

The 5.5km-wide bowl is buried under shale sediments west of Stockton, in San Joaquin County, and is thought to be between 37 and 49 million years old.

*snip*

Data from a 3D seismic survey of an ancient sea bed clearly shows a circular structure buried 1,490-1,600m (4,890-4,250ft) below sea level.

The Victoria Island structure, as it has been named, has a concentric rim surrounding a "central uplift" - a peak at the centre - which are both characteristic of impact craters.

This happened when Central California was in the ocean and it probably raised quite a huge tsunami as well as vaporizing a lot of ocean floor and water itself. This would be a sudden, very abrupt change in the climate and the reverberations would have lasted for quite a few years.

We can clearly see from the dramatic fossil record that aside from the very, very big extinction events which everyone has accepted, the Permian and the end of the dinosaurs, we have many 'mini' extinction events and as geologists find more and more hidden strike zones, it is notable that they occured when other, smaller extinctions and dramatic, SUDDEN changes occured.

Unlike the slower evolution over time as temperatures rise or fall or continents move slowly over the equator and then over the poles, these many day/night changes the punctuate the history of life whereby a teeming ecosystem suddenly collapses and mostly the smaller species survive and begin to proliferate and fill all the empty niches.

Here is another suspicious major strike event which, like the Chicxlub and the Stockton strikes, was in the ocean.

One of the worst cosmic collisions known to have rocked what is now the United States carved a huge crater from the present-day mouth of Chesapeake Bay.

The asteroid or comet impact kicked a cloud of debris high into the atmosphere, spawned devastating tsunami waves up to 2,000 feet (610 meters) high, and carved out the largest crater ever found in the United States, researchers say.

It also left a legacy of salty groundwater that threatens the fresh water supplies of some 2 million people who live in and around the unstable crater eons later.

*snip*

The water woes started when a huge object slammed into Earth 35 million years ago. The impact left a now-buried, unstable crater rim that still generates earthquakes as it shifts and sloughs around.

"The asteroid or comet probably measured about 1 to 2 miles (1.6 to 3.2 kilometers) in diameter and was traveling at tens of miles per second," said Greg Gohn, USGS Chief of the Chesapeake Bay Impact Crater Project. "It gouged a crater 53 miles (85 kilometers) wide and fractured bedrock to a depth of well over a mile. Today, those disrupted rock units greatly affect the pattern of groundwater flow throughout southeastern Virginia."

Perhaps meteorites that hit land don't have the strong effect of the ocean strikes for various reasons. For example, the continental thickness may respond differently from ocean floors which are perhaps thinner and so the lithosphere is much more affected. Also, there is no extra water added to the atmosphere suddenly and I do know that sudden global flooding would create tremendous habitat damage whereas simple dust and dirt would cool things down but not wash away whole ecosystems.

On top of all this, I am certain volcanic action across the planet would cause lots of side-events, maybe even things like the Siberian Traps which coincided with the strike in Antarctica at the beginning of the Permian Extinction or the Deccan Traps which happened perhaps the same way in the later extinctions.

The greenhouse gas effect coupled with the rotting of lots of destroyed biomass is why we have strata instead of a gradual change.

Close to 23 million years ago, a great flaming rock fell from the sky. It slammed into the arctic and left a steaming crater 20 km across. It was not the largest object to have crossed Earth's path, nor was the impact the only one of its time. But for life on Earth, the rock had found the worst possible place to crash into.

The area surrounding the impact was undoubtably devastated immediately. Thick clouds of ejecta in the air would have stalled photosynthesis across much of the Northern Hemisphere, breaking down food chains across North America and Eurasia and leading to the starvation of millions of animals. As devastating as this catastrophe must have been, the scorching of the sky was not the most serious consequence of the collision. The blast of the impact had, after vapourising the surface sediments, encountered bedrock rich in anhydrite (calcium sulphate) and various carbonates. Great quantities of this material, some from over 1.7 km deep within the Earth, was thrown into the atmosphere where it lead to an increase in greenhouse gases and deadly falls of acid rain.

*snip*

On both Spec and, RL the eroded scar of the 23 million year-old impact, known as the Haughton crater, sits in the high arctic of North America (75°22'N, 89°41'W). The effects of the impact on RL's Cenozoic biosphere is still being investigated and it has been implicated in a number of regional extinctions. What is certain however, is that no megafaunal extinction event of the magnitude of Spec's decimated northern dinosaur faunas occured in our native timeline.

Namely, the strata in the rocks often change with the fossils...quite abruptly. And at significant times, across many ecosystems in many areas simultaneously. A sudden change in percipitation can cause tremendous, swift changes in the landscape and a place that was, say, a fertile valley or a rich swamp, can instantly, in one year, be covered over with tons of sand or mud or other run-off items which we see over and over again in the geological record.

(AP) Researchers studying rocks from Antarctica have found chemical evidence that a huge meteorite smashed the Earth 251 million years ago and caused the greatest extinction event in the planet's history, killing about 90 percent of all life.

The extinction, which scientists call the Permian-Triassic event, came some 185 million years before a similar meteorite collision with the planet killed off the dinosaurs.

"It appears to us that the two largest mass extinctions in Earth history ... were both caused by catastrophic collisions" with meteoroids, the researchers say in their study appearing this week in the journal Science.

And these are so obvious but when it comes to the other obvious events when the world suddenly dropped the ball on a host of previously successful species and suddenly veers off in a totally new direction, these happenstances are not singular at all but are COMMON.

This latest discovery of a big meteorite strike coincides in time, perhaps, of a great, great change in the ecosystem: the colonization of much of the earth by grasses.

Bremer K.
Department of Systematic Botany, Evolutionary Biology Centre, Uppsala University, Sweden. kare.bremer@ebc.uu.se

Phylogenetic interrelationships among all 18 families of Poales were assessed by cladistic analysis of chloroplast DNA rbcL and atpB sequences from 65 species. There are two well-supported main clades; the graminoid clade with Poaceae (grasses), Anarthriaceae, Centrolepidaceae, Ecdeiocoleaceae, Flagellariaceae, Joinvilleaceae, and Restionaceae; and the cyperoid clade with Cyperaceae, Juncaceae, and Thurniaceae. A sister group relationship between Poaceae and Ecdeiocoleaceae is identified with strong support.

The sister group of this pair is Joinvilleaceae. These relationships help in elucidating the evolution of grasses and the grass spikelet. Dating of the tree was done by nonparametric rate smoothing of rbcL molecular evolution. Most Poales families date back to the Cretaceous >65 million years ago (mya). Dispersal-vicariance analysis indicates that the Poales originated in South America, the cyperoid clade in West Gondwana (South America or Africa), and the graminoid clade in East Gondwana (Australia). The Trans-Antarctic connection between South America and Australia, and its breakup about 35 mya, probably influenced the evolution of the Poales and the graminoid clade in particular, leading to vicariance between the continents, but the separation of Africa from the other Gondwanan areas, completed about 105 mya, is too old for such a relation.

We know precious little about the evolution of grass but we do know this coincided with the rapid evolution of horses and cows and other grass-grazing hoofed mammals who were all insignificant parts of the pre-strike ecosystem. And most of the big tree grazers vanished without any chance to evolve within the new world order!

Let's look at horses: looking at their early shape, they were furtive, small creatures with fairly big feet compared to their tiny bodies, splayed toes such as swamp animals or creatures living on very spongy ground would have. We are fortunate to see close-up their evolution from the very small, shy creatures to the plains-dwelling, grass eating running in large herds, large mammals. Why would they leave the swamps and dense growth places to run on plains?

Perhaps, in the catastrophe of this lesser-extinction event, the sudden floods coupled with a total change in the lay of the land meant their previous habitat was ruined and only mutant forest-proto-equines survived while the older, earlier models were literally swept away by floods.

The survivors had to be the ones not living next to streams of lowlands but the ones that were on the fringes of the forests and thus, were not swept away. But their food source dried up or was covered by dirt so they fended for themselves, eating stuff that was hard to digest or chew.

The survivors of this harsh environment passed on stronger teeth, feet that could run on hardened mud and stomach parasites that could break down the thick, nearly indigestible fibers of a plant that had few takers previously: the earliest grasses.

All the grass-grazers and the grass itself evolved rapidly in tandem, taking over much of the earth. We now have bamboo, rice, wheat, sugar cane and all sorts of grasses all over the earth and we exploit them very heavily for our own eating. This new life-form is disliked by all the other monkey/primate family, for example. They would all rather eat insects than any grass form. But the grass eaters triumphed rapidly and dominate the earth, quite literally.

If we were unable to eat grasses, we would not be so great a population today, for example. Using our brains, we figured out how to eat grass too. And this gave us tremendous power over the environment.

The grass grazers nearly all developed an important device the grasses need in order to colonize the hard-mud areas devastated by meteorite strikes: hooves. As a person who owns grass grazers and cares for fields, the sharp hooves break up the hard soil and 'plows' it for the grasses. If the grazers don't chop up the dirt, the roots of the grasses get too entangled and they strangle themselves. When I want more grass to grow, I take out the tractor and tear up the pastures and then reseed them. Indeed, the strength of grasses both in the roots and the seeds.

All the grazing animals graze different levels of grass: cattle prefer the tops, horses, the middle and sheep the stubs. Put sheep in a deep-grass pasture and they will be unhappy until they trample it in. Put a cow in a cropped field and it will starve. Horses will jump fences for their own prefered grassing rights.

We are in the Age of Grazing Grasses. Humans and the various animals that graze on grasses control the environment in many places, sometimes very ruthlessly. The hunters and eaters of grazers also rule. And the jungle/tree environment is in retreat.

In the great plains, few trees grow simply because the grazers will mow them down long before they pass sapling stage. In winter, the grazers will strip the bark, they trample the saplings into the earth and this vastly changed the earth. Instead of vast forests and fens, we have grassy plains that stretch for thousands of miles.

Grasses cannot colonize forests. They can only do this when forests are destroyed and then, only if there are sharp-hooved grazers ruthlessly removing all potential trees. This happened before the first Ice Age. And humans, very early on, felt an affinity with the grazers on the grassy plains.

Ejected from the Garden of Eden jungles, we stood up and began to follow the new herds that had so violently changed the planet. We became the herders and the sower of the seeds of these grasses. Possibly the very first thing ever made by humans that wasn't either a stick nor a stone was some woman weaving a sling out of grasses or rushes for her baby.

Culture of Life News Main Page

The Grand Teton Mountains Are Subsiding While Yellowstone Rises

Elaine Meinel Supkis

The Grand Tetons are sinking, not rising and the floor of the huge Yellowstone caldera is rising and falling as if the earth is breathing uneasily. Time to talk about catastrophic caldera events and the lithosphere.

Yellowstone isn't the largest one in the world but is certainly one of the most potentially active ones in the world right now.

Supervolcanoes can sleep for centuries or millennia before producing incredibly massive eruptions that can drop ash across an entire continent.

One of the largest supervolcanoes in the world lies beneath Yellowstone National Park, which spans parts of Wyoming, Montana and Idaho.

Though the Yellowstone system is active and expected to eventually blow its top, scientists don't think it will erupt any time soon.

I like how scientists always have the dangers hedged heavily. They are afraid of panicking people and then being blamed when nothing happens so they play it safe by giving us really, really bad news and then assure us, it won't happen soon so we have nothing to worry about.

Only this is also false. Frankly, we haven't the faintest idea when it will happen: all we know is, it will. Just like the San Andreas fault and all the other great faults fracturing California: all of them will, over time, cause great earthquakes. We can't say what day. This doesn't mean they should be ignored, quite the contrary. Humans like to pretend we control this planet and even as we dig down deep, suck up fluids or rearrange the soil on top and alter the air, our efforts are truly puny when compared to what Mother Nature can do with a flick of her smallest finger.

From the article:

The data shows that the caldera floor sank 4.4 inches from 1987 until 1995. From 1995 until 2000, the northwest rim of the caldera rose about 3 inches, followed by another 1.4-inch rise until 2003. Then between 2000 and 2003, the caldera floor sank a little more than an inch.

And then from 2004 to 2006 the central caldera floor rose faster than ever, springing up nearly 7 inches during the three-year span.

"The rate is unprecedented, at least in terms of what scientists have been able to observe in Yellowstone," Smith said.

These results could explain another surprise finding: The ground along the Teton fault — an active fault running 40 miles north-south along the eastern base of the Teton Range in the Grand Teton National Park in Wyoming just south of Yellowstone — moves in the opposite direction compared to what's been previously thought.

I cannot say, 'IF Yellowstone blows up,' because there isn't the slightest doubt it will blow up. 'WHEN Yellowstone blows up, we will pretty much be destroyed as a nation,' is pretty much correct. For past explosions have blanketed the Midwest with volcanic tuff. And of course, there would be some re-arrangement of all those faultlines in California, Oregon, Washington and maybe all the way over to Arizona and New Mexico.

Most farms would vanish in our vast grain belt. And we would relearn the lessons our distant ancestors learned: evolution's tools are death and climate change. Certainly, our climate will undergo some revision. So if one wants to worry about something major, this is it. Since our farms feed a good part of humanity, the very least would be many humans would cease to worry about obesity. If an Ice Age begins, then we are in stupendous trouble.

We can't stop, deflect or change the facts here. There is no 'cure' for this problem. Nonetheless, it is good to understand the planet we live upon. Frankly, I am not happy to hear the Grand Tetons are dropping. This isn't a good sign and the fact that scientists were sufficiently alarmed, they talked to the press proves there is more to this than the bland article paints.

More from the article:

Researchers found that just the opposite is happening with Jackson Hole — the valley below the Teton. The valley is rising up slowly and the mountains are dropping down.

What the researchers think is happening, on a short-term basis at least, is that the bulging Yellowstone hotspot north of the Tetons is pushing against the north edge of Jackson Hole and jamming it against the mountains.

Under Yellowstone sleeps a dragon which is now shuddering and flexing his armored coils. How does this volcanic caldera act? This has not been witnessed by humans except they looked up to the skies one day when they were figuring out how to use stones and sticks and saw a thick blanket of white ash suddenly come running out of the West and there were a series of eerie, loud, hollow booms and the earth shook ever so slightly and the air suddenly smelled really bad.

Then the weather turned really, really foul. Lots of these human ancestors died. How do these mega-caldera events happen?

Just this year, a geologist used chemistry to decode how these volcanic events unfold.

ILYA N. BINDEMAN
Geochemist and assistant professor in the department of geological sciences at the University of Oregon

We began our analyses with a focus on a particularly efficient oxidant, ozone. Ozone is a gas molecule made up of three oxygen atoms best known for shielding the earth from the sun's dangerous ultraviolet rays. Because of rare chemical transformations that certain gases undergo in the presence of that intense solar radiation, ozone is characterized by an anomaly in its so-called mass-independent oxygen isotope signature, which in simple terms can be thought of as an excess of oxygen 17.

When ozone or any other oxygen-rich molecule in the stratosphere interacts with SO2, it transfers its oxygen isotope signature to the resulting acid--that is, the oxygen 17 anomaly persists in the new acid. In 2003 geochemists at the University of California, San Diego, found the first evidence that this signature is also preserved in the oxygen atoms of the acid that later falls as rain and in the sulfate compounds that form as the acid rain reacts with ash on the ground.

Namely, by tracing these isotopes in the ground where these sort of volcanic events have happened, he can figure out how each step of the eruption progressed. The data explains the mechanics of mega-caldera eruptions and from this data, he was able to suggest a theory as to how the earth's magma doesn't just come bubbling out of the ground or huffing and puffing, bulding a volcanic mountain but intead, blows up totally.

He continues:

A supereruption occurs after the pressurized magma raises overlying crust enough to create vertical fractures that extend to the planet's surface. Magma surges upward along these new cracks one by one, eventually forming a ring of erupting vents. When the vents merge with one another, the massive cylinder of land inside the ring has nothing to support it. This "roof" of solid rock plunges down--either as a single piston or as piecemeal blocks--into the remaining magma below, like the roof of a house falling down when the walls give way.

Dr. Bindeman makes a good analogy here. When it snows too much, sometimes the outer walls of barns will bulge and then with a loud roar, the roof caves in. When I see buldging walls on buildings, I know they will eventually collapse. Same with retaining walls or dams: bulging outwards means they will explosively give way very suddenly.

I also adore this scientist, he thinks the same way as I do:

Scientific techniques for studying and monitoring volcanoes of all sizes are developing with all deliberate speed. But no matter how much we learn, we cannot prevent an eruption. And what can be said about the aftermath of the most catastrophic occurrences is still speculative at best. The good news, though, is that researchers now know enough about the sites of possible eruptions to predict with reasonable assurance that no such catastrophe will happen anytime soon.

Except I am crueller: we do know what happens next! This is how we and all sorts of creatures evolved! And this goes even more so with us humans for the Yellowstone and the Toba, Indonesia calderas created us as humans, they are the rock and hard place that forced us on a deadly march of survival of the fittest, in our case, the smartest.

The equivalent of geniuses coped better with the violent changes than the less thoughtful specimens of our race. The level of catastrophe is Toba blows is bad enough but Yellowstone is that and more plus it sits smack dab in the center of our nation and its effects will be tremendous.

Increasingly during this last 20 years as geologists begin to really understand the meaning of plate tectonics, their ability to track and analyse the Yellowstone area in a 500 mile radius brings up more and more uncertainties and questions.

Sylvester found that, between 1988 and 1991, the valley east of the fault (Jackson Hole) rose ten millimeters relative to the Teton Range. This was probably due to the rise of the water table caused by refilling Jackson Lake, eight kilometers north of the leveling line. Additionally, the valley tilted toward the mountains.

However, between 1991 and 1993, to Sylvester's surprise, measurements indicated that the valley tilted slightly eastward, away from the Teton Range. This is contrary to the long range tectonic tilt inferred from the slope of the valley floor and from its subsurface strata.

At first Sylvester and Smith postulated that the uplift and tilting was caused by raising and lowering of the water table due to the relatively rapid draining and filling of Jackson Lake. But the 1997 survey results resembled those of the 1989 and 1991 surveys, and the uplift of the valley near the fault increased another eight millimeters. The uplift of the valley, instead of the mountains, implies that the Teton fault is back-slipping in response to regional crustal shortening. Global Positioning System satellite measurements that Smith has acquired in both Grand Teton and Yellowstone National Parks in the past decade support this hypothesis.

The entire Western North American landmass is being yanked along in one direction while the Atlantic rift is violently shoving it westards while the Pacific Plate is being shoved northwards by Australia. Along the Asian/Australian side of this mess, there are many vast earthquakes, many more than on the North/South American side. The violence of this half of the planet is greater than the other half. The Pacific Plate's center is relatively quiet except for the Hawaiian hot-spot. But the North American Plate is seeing increasing deformation of the western half of its own landmass. The complexity of these plates and some underlying plates our continent has already steamrolled under makes the geology of the Rocky Mountains region so complex.

Based on these subsurface data, the Granite Ridge fault is described here as a true tear fault confined to the hanging wall of an uninterrupted, 30°-dipping Piney Creek thrust, segmenting hanging-wall thrust displacement between the Piney Creek block on the south and Walker Mountain block on the north. Slip on the Granite Ridge tear fault is expressed at the surface along the eastern margin of the Bighorn Mountains, west of Story, Wyoming, as a resequent fault-line scarp with 2000 ft (600 m) of relief, and with 3.3 mi (5.3 km) of left separation of steeply dipping, Paleozoic rocks. Based on measurement between piercing points produced by the lines of intersection of the steeply, east-dipping Cambrian-Precambrian unconformity with the Piney Creek thrust surface along either side of the Granite Ridge tear fault, a (reverse) left-oblique slip of 15,000 ft (4500 m) is measured on this tear fault zone. Thus, 30,000 ft (9100 m) of net slip on the Piney Creek thrust in the Piney Creek block decreases to 15,000 ft (4500 m) of net slip in the Walker Mountain block, and slip on the thrust further declines northward. The described Granite Ridge tear fault–Piney Creek thrust geometry may provide a useful model in the investigation of similar fault-offset mountain fronts within the Laramide foreland province of the Middle Rocky Mountains.

This is a topographic map showing some of the major volcanoes or caldera that I could map over this image so far (I only got some of them). The main thing is the long line of major caldera events caused by the North American continent moving over the spot where, like with Hawaii and the Solomon Islands, there is some deformation in the lithosphere which deforms the crust. I also show where the lithosphere broke away and fell, according to researchers last month.

Here is a graph showing how the land on one side of a fault zone is stable while the other is rising and falling as if a dragon were moving about below.

Graph of height changes among permanent bench marks in leveling base line across Teton normal fault in Grand Teton National Park. Graph assumes 1989 survey as the datum, bench mark GT42 is arbitrarily held fixed. The fault is depicted as the vertical dashed line - the Teton Range (footwall) is west of the fault, the north part of Jackson Hole (hanging wall) is east of the fault. Uncertainty of bench mark heights in each survey is about equivalent to the diameter of each dot or circle. Standard deviation of bench mark heights per kilometer of leveling is 0.08 mm. The data are extrapolated into a 17 km-long straight line that extends from GT01 at the Snake River near Deadman Bar to GT44 in the core of the Teton Range. The traverse path distance is 22.1 km.

The dotted line in the middle of the graph represents the faultline running along the Grant Tetons.

All of the main geological features of this area are fairly recent, all occuring during the Age of Mammals.

In Miocene time about 9 million years ago, a 40 mile (64 km) long steeply east dipping normal fault system deepened the Jackson Hole basin and started to uplift the westward-tilting eastern part of the Teton Range (the youngest mountain range in the Rocky Mountains).[11] Eventually all the Mesozoic rock from the Teton Range was stripped away and the same formations in Jackson Hole were deeply buried. A prominent outcrop of the pink-colored Flathead Sandstone exits 6,000 feet (1830 m) above the valley floor on the summit of Mount Moran. Drilling in Jackson Hole found the same formation 24,000 feet (7300 m) below the valley's surface, indicating that the two blocks have been displaced 30,000 feet (9100 m) from each other. Thus an average of one foot of movement occurred every 300 years (1 cm per year on average).[12]

One has to marvel how the earth must have shaken like a rung bell when that rather large object struck it at the end of the Age of Dinosaurs! The lithosphere must have buckled and cracked badly as well as every fracture zone disturbed. One imagines more than one volcano blew up in this same time period. Perhaps the indentation that caused the Yellowstone caldera chain to form at this time was directly caused by the Chicxulub asteroid/meteorite event?

North America was partially underwater back when this happened. I drew this crude map to show where the latter day Yellowstone caldera formed. It is interesting that this occured on the edge of this vast sea which was shoved higher and higher as the North American continent shoved itself over other plates to the west.

The path Yellowstone's volcanic activity has taken has been only for a relatively short period, geologically speaking.

Yellowstone's volcanism is only the most recent in a 17 million-year history of volcanic activity that has occurred progressively from southwestern Idaho to Yellowstone National Park. At least six other large volcanic centers along this path generated caldera-forming eruptions; the calderas are no longer visible because they are buried beneath younger basaltic lava flows and sediments that blanket the Snake River Plain.

I was looking very closely at the maps while trying to higlight the various geological features around the Yellowstone caldera when I noticed right at the top of the beginning of the Yellowstone basin where previous incarnations of that caldera formed was this huge, perfectly round geological formation. So I spent a few hours figuring out what on earth that was.

It is the site of one of the greatest volcanic events in North American history!

Flood basalts appear to form during the initiation of hotspot magmatism. The Columbia River basalts (CRB) represent the largest volume of flood basalts associated with the Yellowstone hotspot, yet their source appears to be in the vicinity of the Wallowa Mountains, about 500km north of the projected hotspot track. These mountains are composed of a large granitic pluton intruded into a region of oceanic lithosphere affinity. The elevation of the interface between Columbia River basalts and other geological formations indicates that mild pre-eruptive subsidence took place in the Wallowa Mountains, followed by syn-eruptive uplift of several hundred metres and a long-term uplift of about 2km. The mapped surface uplift mimics regional topography, with the Wallowa Mountains in the centre of a `bull's eye' pattern of valleys and low-elevation mountains. Here we present the seismic velocity structure of the mantle underlying this region and erosion-corrected elevation maps of lava flows, and show that an area of reduced mantle melt content coincides with the 200-km-wide topographic uplift. We conclude that convective downwelling and detachment of a compositionally dense plutonic root can explain the timing and magnitude of Columbia River basalt magmatism, as well as the surface uplift and existence of the observed melt-depleted mantle.

Here is a geological diagram showing all the major fault lines which seem to all converge on or run out of the very spot where the greatest volcanic activity happened in the past: the center of the Blue Mountains.

Indeed, looking at maps like the ones here showing the volcanic flow from that one spot. (Click to see maps) I was stunned to see the extent of the lava flows: it covered much of Washington State and Oregon! The Blue Mountains are not as spectacular as some of the other mountains out there but because of its very size, it is hard to see as something gigantic except from space where it sticks out like a sore thumb.

Recently a geologist my husband worked for at the NY State Museum discovered a good-sized meteorite strike in New York State at Panther Mountain when he was examining satellite photographs. These photos are fantastic tools for seeing the bigger picture.

I am now guessing that the Blue Mountains were actually the first Yellowstone events. It began very explosively, a massive amount of magma flowed because the break was deep and very significant. Only the Deccan and Siberian Traps are possibly greater and each of them happened at the same time as a major asteroid strike and die-off of species.

Yellowstone today is the quieter manifestation of this disturbance. But due to its internal structure, if the 'roof' collapses suddenly, it just won't sink into the ground and melt, it will blow up. And we still don't know exactly why or how or much of anything except by intelligent guesses and patient detective work.

Culture of Life News Main Page

The Lithosphere Has Collapsed In Huge Areas

Elaine Meinel Supkis

Two tremendously interesting geological stories appeared this week. They both concern the discovery that large sections of the lithosphere have collapsed in certain parts of the earth. This information doesn't surprise me at all, I think this is common place and is part of the natural effects of tectonic plate movement and over the last 3 billion years, has greatly altered the nature of the proto-continents as well as the sea beds.

Actually, there are several 'open wounds' in the lithosphere.

Scientists are to sail to the mid-Atlantic to examine a massive "open wound" on the Earth's surface.

*snip*

The hole in the crust is midway between the Cape Verde Islands and the Caribbean, on the Mid-Atlantic Ridge.

The team will survey the area, up to 5km (3 miles) under the surface, from ocean research vessel RRS James Cook.

*snip*

Dr MacLeod said the hole was an "open wound on the surface of the Earth", where the oceanic crust, usually 6-7km thick (3.7-4.3 miles), was simply not there.

One of the things that always intrigues me is the number of earthquakes at the 10km level. Many 8 to 9 mag earthquakes like the terrible Boxing Day Tsunami event, are at that depth. Click on the chart here to enlarge it. This is from 3/3/2007, a normal day with a long list of earthquakes. Nearly half of them are at the 10 km depth.

Up until recently, we were taught that the lithosphere was the same all over except where it was being subducted under a continent, for example. Also, theories about tectonic plate movements suggested that the continents were basically unchanging except at the outer edges where they would bump into each other or join together like India crashing into Asia. But as scientists probe this planet's innermost structures, a totally different picture is now emerging, one that is very disturbing.

The continents are actually quite prone to falling apart because the base upon which they rest can suddenly collapse.

The discovery that a segment of the ocean floor, not just the lithosphere but the whole thing, fell away suddenly into the depths of the mantle, is an eye-opener indeed. This event happened where the earth's plates are moving apart but I suspect this is the wrong imagery. Perhaps the better idea is to think of the split that runs the entire planet from the Artic to the Antarctic plate is a serious crack in the earth.

If we visualize this crack, it opened approximately 200 million years ago. The ground began to fall and a rift valley opened up and this was no ordinary rift valley. Many of these open up all the time all over the earth. This one was very long and very deep. The rift in Siberia at this time opened up and out poured the greatest lava flow that we know of. Because of this, Siberia grew thicker and bigger.

But North America, South America and Africa began to split apart and instead of lava flowing in huge amounts, a teeming rift valley was born. And when the oxygen levels collapsed, causing the greatest extinction on earth at the end of the Permian, many of the survivors lived in this epic rift valley. What tremendous changes in the climate and earthquakes, tsunamis and other events happened when this mighty rift valley deepened and deepened until a line of linked lakes fed by water pouring off the sides of the ever-higher cliffs and then one day, the ocean came roaring into this rift, totally severing these three continents?

Since then, material from the mantle has been flowing out of this gigantic crack. The continents aren't gliding along, they are not floating, they are being pushed apart by the epic forces of the inner energy of the planet. Perhaps the weight of the oceans are pushing down and thus, like a toothpaste tube, forcing lava upwards.

But this collapse of the whole seabed is interesting because there are obviously some very powerful forces at work and I think this is happening all over the planet, not just underwater!

First, let's look at the Cape Verde Islands which are volcanic entities and are part of the Atlantic sea bed, not any continent:

(1) Department of Geosciences, Purdue University, 47907 West Lafayette, IN, USA
Accepted: 1 March 1982

Abstract: Geoid height anomalies, as determined by satellite altimetry, suggest that the Cape Verde Rise is in local isostatic equilibrium, supported by a low-density root of altered lithosphere. A depth anomaly map shows the Cape Verde Rise to be approximately 1600 km wide and 2km high. Removal of a quadratic surface from the observed geoid heights leaves a residual positive anomaly with the same shape as the rise and an amplitude of about 8 m. The ratio of residual geoid height anomaly to depth anomaly is consistent with an isostatic root only 40 km deep on average.

So, the lithosphere there is 'altered'. Unfortunately, I couldn't read the entire paper. I have noticed that more and more information is online but at the same time, they are locking it away from anyone without a deep wallet and since I am not an university employee, etc, this is prohibitively expensive. So I will hazzard that the fact that volcanoes formed at this spot is because the ocean's base, its lithosphere, is deformed there and it would not shock me to learn the entire lower base simply fell through and is now falling through the less-dense mantle.

This is in line with the collapsed sector in the middle. Perhaps speed which this giant crack in the earth is moving open has caused tremendous instability, perhaps even stretching of the lithosphere? If we view this crack not as a narrow area but as the distance between the East Coast of the USA and the West Coast of Africa or the East Coast of South America versus the West Coast of Africa, then the truly awesome and terrifying proportions of this disordering of the planet can be grasped: it holds a fifth of the planet's ocean waters, about 106,400,000 square kilometers (41,100,000 sq mi); it is between 2,000 to 3,000 miles across! How swiftly has it widened?

According to scientists, it is slightly less than 6 cm a year. But over 200,000,000 that covers quite a few miles! North America split away first which is why it is 3,000 miles away from Africa, South America is less because the great crack took time, opening up like a giant zipper, bit by bit, over time, the ocean invading dry land relentlessly.

There is no 'ring of fire' involved in all this, except for a few volcanic locations such as Iceland or the Canary Islands, there is not much earthquake or volcanic activity in this dynamic rift zone. The goo flowing out of this gigantic crack is so dynamic, it is shoving North and South America right over the Pacific plate and all other plates in the West. The mountain building this is causing is epic. The mountains on the East Coasts are extremely old: pre-split.

From my own blog (seriously, it was the number one article in the Google search!) last summer, a meteorite or comet struck Antarctica at the same time this great split began. We don't know if there is a direct connection but perhaps there is? This meteorite strike the may have ended the Permian era was far bigger than the one that might have delivered the death blow to the age of dinosaurs 65 million years ago.

We know from gravity pictures of the moon, for example, a major meteorite strike will cause geological changes on the opposite side of the blow, in this case, the Artic may have responded to the shattering blow and perhaps this made all the natural valley systems turn into major rift zones and the tearing happened where the mantle had the least landmass-pressure?

I would have to make an animation showing how this might have worked (anyone out there have the skills? I'll draw the cartoons.)

Since today's article is about how the mantle rather than magma, was directly created when part of the lithosphere collapsed into the mantle, proof of this is the appearance of 'serpentine rock' so I decided to look up other places with this sort of rock.

Naturally occurring asbestos, often found in serpentine rock formations, is present in several foothill areas of Placer County. When naturally occurring asbestos containing material is disturbed asbestos fibers may be released and become airborne, thereby creating a potential health hazard.

So this is where asbestos comes from! North America is one place with lots of asbestos mines! If this is so, then the lithosphere has fallen in the past! Maybe this happens over and over again. I suspect that where there is asbestos, there was an ocean rift that exposed the mantle. Since the older parts of the landscape on dry land have sectors with asbestos, these means it is not a once in a very rare while thing but has happened over and over and over again.

This takes me to yesterday's block-busting geological story about 'lost ocean' in Earth's mantle:

Ker Than
LiveScience Staff Writer

Scientists scanning the deep interior of Earth have found evidence of a vast water reservoir beneath eastern Asia that is at least the volume of the Arctic Ocean.

The discovery marks the first time such a large body of water has found in the planet’s deep mantle.

The finding, made by Michael Wysession, a seismologist at Washington State University in St. Louis, and his former graduate student Jesse Lawrence, now at the University of California, San Diego, will be detailed in a forthcoming monograph to be published by the American Geophysical Union.

Now something really bothers me about satellite photos of the Earth: where ever there is massive mountain-building such as the Himalayan, right next door, there is a collapse. Many places on Earth are circles of mountains surrounding a totally collapsed valley. Some of these are gigantic like the Central Valley of California and the Central Valley of Chile!

Now we learn the lithosphere under China has collapsed and even more interesting for me, the one under the USA and Mexico where Texas, New Mexico and eastern Arizona come together has collapsed, too!

All over that very region, there is rifting! Many cracks that open and spew out lava, lots of 'teeth' mountains caused by these tears! At the same time, the entire continental mass is being relentlessly shoved over the Pacific so this made no sense at all except now it does. Perhaps this is why Baja California is detached from Mexico? Namely, it runs parallel to the western edge of this possible collapsed lithospheric plate. Certainly, the history of that region includes the tipping of the entire landscape in odd directions, not merely responding to the east-west axis actions but north-south such as the tilting of Arizona which has caused the Mogollan ridge to rise so suddenly above the much lower Phoenix/Tucson landscape. And which created the Grand Canyon as the water still flowed south despite the landscape tilting more and more to the north.

From the article above:

Previous predictions calculated that if a cold slab of the ocean floor were to sink thousands of miles into the Earth’s mantle, the hot temperatures would cause water stored inside the rock to evaporate out.

“That is exactly what we show here,” Wysession said. “Water inside the rock goes down with the sinking slab and it’s quite cold, but it heats up the deeper it goes, and the rock eventually becomes unstable and loses its water.”

The water then rises up into the overlying region, which becomes saturated with water [image]. “It would still look like solid rock to you,” Wysession told LiveScience. “You would have to put it in the lab to find the water in it.”

Wysession has dubbed the new underground feature the “Beijing anomaly,” because seismic wave attenuation was found to be highest beneath the Chinese capital city. Wysession first used the moniker during a presentation of his work at the University of Beijing.

In places where ocean bed collapses because it is overlaid with non-ocean terraformations, there probably is water. But this collapse is without water, too! Such as the Tibetan plateau, for example. Indeed, I picked several interesting places and behold how frequently there are collapsed areas surrounded by very high mountains! One would imagine that if Italy, for example, is slamming into Europe, raising the Alps, the land leading up to the Alps would be increasingly hilly and mountainous.

But it is NOT! It is totally flat, flatter than all other parts of Italy far from this dynamic area.

This is true of India: where it hits Asia, it is amazingly flat! Ditto the Great Plains of America leading up to the Rocky Mountains. Gently, it tilts upwards and then suddenly, the jumbled mountains begin, as clearly as if a line is being drawn.

I think the 10 km deep lithosphere is very even but is MISSING SECTIONS. And these have collapsed because of the pressure of rifting in the Atlantic. All I can say is, we barely know all that much about our own planet. And the more we learn, the more interesting it is. Solving these riddles is important for humanity, this is our home, after all. It is the most important planet in the entire universe, as far as we humans are concerned.

Click on all these maps which I got from places like Wikipedia, to see how all this works:

It is not friendly towards life forms.

Ultramafic rocks are scattered throughout the California Coast Range, the Trinity Mountains, and the Sierra Nevada foothills. That serpentine is the state rock proves it has caught the eye of California geologists. However, many are perhaps unaware that serpentinites have spawned a unique flora specially adapted to survive on their nutrient-poor soils.

The Rocky Mountains and the Sierras like the Himalayans, were all once seabeds and the relentless, restless forwards motion of the continent has caused them to tilt and fold upwards but they retain tell-tale signs of their origins including fossil sea lifeforms like sea shells, for example.

But even if these lands were flatter and lower, they would simply be like Death Valley which has little organic vitality. Perhaps the mountain-building is assisted by the fact that part of the lithosphere there has collapsed so it is much easier to fold and bend the softer, more pliable upper crust that used to be sea beds?

There are a lot of mysteries about Northern China/Mongolia and Siberia.

SOJA, Constance M., Geology, Colgate Univ, 13 Oak Drive, Hamilton, NY 13346, csoja@mail.colgate.edu, MINJIN, Chuluun, Geology, Mongolian University of Science and Technology, P.O. Box 46/520, Ulaanbaatar-46, Mongolia, and WHITE, Brian, Department of Geology, Smith College, Northampton, MA 01063

Mongolia occupies a key position for unraveling the complex geologic history of central Asia, which amalgamated through the accretion of “exotic” crustal fragments in the late Paleozoic-early Mesozoic. Study of the paleontology, stratigraphy, and sedimentology of Ordovician-Silurian deposits exposed in two Mongolian terranes is adding new data that will help refine paleogeographic models of Mongolia's terranes. The Mandalovoo terrane comprises a nearly continuous Paleozoic island-arc sequence characterized by mildly deformed volcanic and sedimentary rocks overlain by an Upper Paleozoic post-accretionary complex.

Upper Ordovician-Upper Silurian rocks exposed in the terrane belong to the Mandalovoo Formation, a volcanic-sedimentary sequence estimated to be 2500 m thick. Siliciclastic deposits and fossiliferous limestones are interstratified with pillow basalts, andesites, volcanic agglomerates, and tuffs. Well-preserved fossils indicate a spectrum of shallow- and deep-marine environments associated with the growth and expansion of island-fringing carbonate platforms. Higher in the section, limestones rhythmically interbedded with shales document the transition upward into turbidites that formed along a deep-marine slope, perhaps of the adjacent Gobi Altai terrane.

Ordovician-Silurian deposits exposed in the Gobi Altai terrane exceed 3000 m in thickness and comprise one of the least deformed, best preserved, and most continuous stratigraphic sections in Mongolia. The Lower Paleozoic deposits reveal abundant shallow-water indicators, including oncoidal limestones and cross-bedded sandstones that grade upward into biohermal, fossiliferous limestones and domal stromatolites.

These carbonates are interbedded with shales and overlain by Lower Devonian breccias that comprise angular-subrounded limestone clasts; the entire sequence is capped by younger Devonian-Triassic volcanic-sedimentary deposits. Future research on the preponderance of shallow-marine facies in the Gobi Altai terrane will help ascertain its proximity to other terranes, specifically if it is a backarc basin or a dismembered portion of the Mandalovoo arc terrane.

In other words, this was all ocean bed material. Indeed, huge swaths of what is now dry land, was seabed once, more than 200 million years ago. 300 million years ago and earlier, the dry land eroded at tremendous speed, this is during the first several billion years this planet existed. But once life colonized the oceans and then the lands, the dynamics changed a great deal. The Great Plains have this gigantic reservior of water, the Ogalala, thanks to limestone laid down in the Ordovician and Silurian periods. And of course, oil and gas get trapped by salt or limestone from the same organic forces working on the shallow sea floors.

Here are some calculations concerning the kinetic energy of mountain building exerts on the lithosphere below:

To maintain isostasy, the forces pushing down from above the fluid's surface - in this case the ocean floor - must equal the forces pushing up from below, caused by the displacement of denser mantle material by the less dense continental rock of the mountains' roots, according to the following formula:

13,000 feet (s.g. of continent - s.g. of water) + 15,000 feet (s.g. of continent)
= thickness of roots (s.g. of mantle - s.g. of continent)
or
13,000 (2.7 - 1) + 15,000 (2.7) = x (3.3 - 2.7)

(Note that the weight of the first 13,000 feet of continental material above the sea floor is buoyed by the weight of the water around it.) Thus, x (the thickness of the mountain's roots below the sea floor) equals 104,333 feet, and our total mountain range averages 104,333 + 13,000 + 15,000, or 132,333 feet thick. Now, make sure that no other continents are going to get in the way, then go away for a billion or a billion and a half years and let erosion run its course.

Sediments eroded off the mountains will be carried over the edge of the mountains' shore and deposited on the 13,000 foot deep ocean floor. The weight of the accumulating sedimentary deposits will push the deeper sediments down into the mantle, always maintaining isostatic equilibrium (or trying to). When the sediments reach a thickness of around 50,000 feet

( = (13,000 (2.7 - 1) / (3.3 - 2.7)) + 13,000 )
the surface of those sediments will be at sea level, and additional sediments will be washed over them and farther out to sea. As the mountain peaks erode away, isostasy will push the mountains' roots upward, presenting new land to erode, until only the lowest 50,000 feet of the original mountains remains, and whose surface is essentially at sea level as well, forming a peneplain. The roots of the mountains will be sitting in the middle of a flat, nearly sea level continent, ringed by flat plains of horizontal sedimentary deposits. While the total volume of continental material remains the same, the surface area will have increased by 2.65 times.

It seems very odd to me that the mightiest mountains build up higher and higher and don't collapse but they also don't spread, either, they wrinkle up and leave a collapsed core like Tibet. Is this due to stretching the lithosphere as it bulges downwards due to tremendous pressure? And then 'snaps' and releases a section, causing the land on the other side to collapse?

Right next door to where the lithosphere may have collapsed along with a hunk of ocean water, is some other odd things like a rift valley that has the world's deepest lake, which holds one fifth of the world's fresh water!

Lake Baikal is quite a puzzle:

Lake Baikal is in a rift valley, a gorge where the crust of the earth is pulling apart.[8] At 636 kilometres long and 80 km wide, Lake Baikal has the largest surface area of any freshwater lake in Asia (31,494 km²) and is the deepest lake in the world (1637 metres, previously measured at 1620 metres). The bottom of the lake is 1285 metres below sea level, but below this lies some 7 km (4 miles) of sediment, placing the rift floor some 8–9 km (more than 5 miles) down: the deepest continental rift on Earth. In geological terms, the rift is young and active — it widens about 2 centimeters per year. The fault zone is also seismically active: there are hot springs in the area and notable earthquakes every few years. It drains into the Angara tributary of the Yenisei.

Its age is estimated at 25–30 million years, making it one of the most ancient lakes in geological history.

So, even as Japan and all the other 'ring of fire' lands spout volcanoes and the Pacific is shoved under Asia as the great, gigantic tear in the Atlantic shoves all continents aside with tremendous force, despite this, right in the middle of Asia where Siberia and China meet, there is a RIFT? If the lithosphere dropped a 3,000 sq. mile section, then this means the scaffolding between the continental surface and the lithosphere is tremendously weak and stretched and so, surrounded by mountains caused by China slamming into Siberia, we see it opening up RIGHT DOWN THE CENTER, not on one side, but in the middle. The mountains on both sides are MOVING AWAY FROM EACH OTHER even as the Pacific is being violently shoved into this region from the east!

Click on images to enlarge.

Fossil Museum has some nice thumbnail sketches explaining geology.

Silurian Time (440 to 410 MA)
During the Silurian, Laurentia collided with Baltica closing the northern section of the Iapetus Ocean. This collision was preceded in many places by the abduction of marginal island arcs, resulting in the formation of the Caledonide mountains in Scandinavia, northern Great Britain and Greenland, and the Northern Appalachian mountains of Eastern North America. North China and South China had rifted away from the Indo-Australian margin of Gondwana, drifting North across the Paleo-Tethys Ocean. Throughout the Early and Middle Paleozoic, the expansive Panthalassic Ocean covered much of the northern hemisphere. Surrounding this ocean was a subduction zone, much like the modern "ring-of-fire" that surrounds the Pacific Ocean.

'Craton' is a scientific word used to describe the oldest landmasses on earth such as much of Canada, for example.

A craton (kratos; Greek for strength) is an old and stable part of the continental crust that has survived the merging and splitting of continents and supercontinents for at least 500 million years. Some are over 2 billion years old. Cratons are generally found in the interiors of continents and are characteristically composed of ancient crystalline basement crust of lightweight felsic igneous rock such as granite. They have a thick crust and deep roots that extend into the mantle beneath to depths of 200 km.

The thickness of the crust of the oldest cratonic sectors of continents perhaps isn't general, after all. Maybe they are all in danger of some sort of collapse. We know so little. For example, China should have a very thick crust but this is where the biggest collapse happened!

From Wikipedia:

The North China craton is one of the oldest cratonic blocks in the world. It covers an area of ~1.7 million km2 across most of northern China, the southern part of northeastern China, Inner Mongolia, the Bohai Bay and the northern part of the Yellow Sea. The craton is bounded by the early Paleozoic Qilianshan orogen and the late Paleozoic to Mesozoic Central Asian orogenic belt to the west and north, respectively, and the Mesozoic Qinling-Dabie and Su-Lu ultrahigh-pressure metamorphic belts to the south and east, respectively. The basement of the craton can be divided into Eastern and Western blocks, separated by the Paleoproterozoic Trans-North China Orogen (TNCO).

The TNCO is characterized by fragments of ancient oceanic crust, mélanges, high-pressure granulites and retrograded eclogites, crustal-scale ductile shear zones and linear fold belts with sheath folds. These lithotectonic elements contrast with the dominant Archaean tonalite-trondhjemite-granodiorite (TTG) gneiss domes surrounded by minor supracrustal rocks in the Eastern and Western blocks. In addition, petrographic and thermobarometric data have revealed a remarkable difference in metamorphic evolution between the TNCO and the Eastern and Western blocks.

The former underwent a major metamorphic event about ~1.85 billion years (Ga) ago with clockwise P-T paths involving isothermal decompression, suggesting a collisional environment, whereas the latter experienced a major metamorphic event at ~2.5 Ga, with anticlockwise P-T paths involving isobaric cooling related to the underplating of mantle-derived magmas. These differences led some researchers to propose that the TNCO was a continent-continent collisional belt along which the Eastern and Western Blocks amalgamated to form a coherent craton at ~1.85 Ga.

About 300-250 million years (Ma) ago the combined North China and Tarim cratons collided with Siberia to comprise the last stage in the formation of Pangaea. At 220-240 Ma, the North China craton collided with the Yangtze block along the Qinling-Dabie-Sulu orogenic belt. The Eastern Block of the North China craton underwent crustal thinning that began in the Mesozoic and is known to have reduced the thickness of the crust from 200 km to as little as 80 km.

And this 'thinning' was really a collapse according to this week's startling news! And who knows what mega-earthquakes accompanied these collapses! Perhaps this is what the New Madrid Fault's tremendously violent earthquakes are all about? The continuing, extending collapse of the lithosphere in that sector? I knew one geologist who suspected this long ago, at least 60 years ago.

He may be right in the end!

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