highest peaks on earth?

There's quite a difference between "hot springs" and "hot spots"

 

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Underlying hot spots are necessary for the creation of hot springs.

 

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Are you telling us that everywhere in the world that we find hot springs we will find an underlying hot-spot?

A hot-spot is not just a localized heat source. A simple definition of hot spot is "a geologic feature of long-lived active volcanism and high heat flow originating from the mantle." Examples of hot spots include Hawaii, Iceland, Yellowstone and several other, mostly oceanic locals- but to my knowledge, there are no hot spots in the Himalayas.

 

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Vallich may be using the term 'hot-spot' in a rather loose way to mean a zone of elevated temperature. There is no doubt that great increase in sialic thickness due to the collision of two continental plates has raised temperatures within the Himalayan orogen. In that sense, certainly, there are hot spots.
Like you, however, I am unaware of any that fit the conventional definition you have provided. There may have been one or more at an earlier time, but again that runs counter to what I would intuitively expect. The himalaya, like all features related to plate tectonic interaction, are linear features. Hot spots are point sources.
Does not compute.

 

Yes, I did use the word "hot spot" loosely, but only because the question was worded so loosely.

I originally posted:

"Hot-spring waters near the Main Central Thrust (MCT) in the Marsyandi River of central Nepal are caused by hydrothermal interactions with the tectonic metamorphic flux processes below, indicative of magma activity."

The hot springs around the Marsyandi River in central Nepal are due to the underlying hot spots.

 

Hot spots are not necessarily point sources. They can originate from a direct uplift of magma originating from the outer core straight up through the mantle into the lithosphere.

 

As an example - although I think we already defined this on another thread?

"The Snake River Plain and the Yellowstone Hot Spot: The geysers, hot springs, and bubbling mud pots of Yellowstone National Park indicate there is extra heat beneath this corner of Wyoming. Geologists and volcanologists think the heat is from a hot spot beneath Yellowstone. A long line of features that extends to the west from Yellowstone are interpreted to be the track left in the continent from the hotspot. The Yellowstone calderas are the youngest and mark the approximate location of the hotspot. Yellowstone has had three very large eruptions in the last 2 million years. During each event, a large volume of rhyolite magma was erupted from a shallow level in the crust and the large caldera formed. These eruptions occurred 2.0, 1.3, and 0.6 million years ago. The volume of lava erupted makes the 1980 eruption of Mount St. Helens look very small."
http://volcano.und.nodak.edu/vwdocs/volc_images/north_america/yellowstone.html
"

 

If we are speaking of "hot spots" in a tectonic framework (which fits your definition), rather than as a regional or localized heating of the crust- then by definition a "hot spot" is a point source. The ultimate origin of hot-spots is quite controversial now. There are still those that call for deep mantle plumes originating at the core-mantle boundary, but another group has emerged that cites evidence of a shallow, probably asthenosphere, source with little to no mantle contribution.

Yellowstone is, in fact, a point source. It just so happens that the North American plate has been moving over the hotspot for the last 17 million years or so- but the present Yellowstone hot spot is located underneath or to the northeast of Yellowstone caldera. While the Snake River Plain may be the track of Yellowstone hot spot- I don't think anyone suggests the hot spot (mantle plume) still exists beneath the SRP.

 

Yes, I agree with you. But what I am saying, and stated above, is that underneath that hot spot point source is an underlying source of magmatic activity either caused by convection currents in the mantle or a direct linear vertical uplift of magma from the outer core of the Earth: these are the two sources of a "hot spot."

 

"I don't think anyone suggests the hot spoy (mantle plume) still exists beneath the SRP."

As stated: "eruptions occurred 2.0, 1.3, and 0.6 million years ago." And we expect them to occur again.

"the hot springs and geysers of Yellowstone....are fueled by heat from a large reservoir of partially molten rock (magma), just a few miles beneath. As this magma-which drives one of the world’s largest volcanic systems-rises, it pushes up the Earth’s crust beneath the Yellowstone Plateau....Thousands of small quakes are recorded each year by the seismographic network of the Yellowstone Volcano Observatory (YVO), a partnership of the U.S. Geological Survey (USGS), the University of Utah, and Yellowstone National Park. Faults and fractures also allow surface water to penetrate to depth and become heated, rising again to produce hydrothermal (hot water) features, such as geysers. Steam and hot water carry huge quantities of thermal energy to the surface from the magma chamber below. Continuing up-and-down ground motions on the Yellowstone Plateau reflect the migration of both hydrothermal fluids and magma below the surface.

Each of Yellowstone’s explosive caldera-forming eruptions occurred when large volumes of “rhyolitic” magma accumulated at shallow levels in the Earth’s crust, as little as 3 miles (5 km) below the surface. This highly viscous (thick and sticky) magma, charged with dissolved gas, then moved upward, stressing the crust and generating earthquakes. As the magma neared the surface and pressure decreased, the expanding gas caused violent explosions.

Since Yellowstone’s last caldera-forming eruption 640,000 years ago, about 30 eruptions of rhyolitic lava flows have nearly filled the Yellowstone Caldera. Other flows of rhyolite and basalt (a more fluid variety of lava) also have been extruded outside the caldera. Each day, visitors to the park drive and hike across the lavas that fill the caldera, most of which were erupted since 160,000 years ago, some as recently as about 70,000 years ago. These extensive rhyolite lavas are very large and thick, and some cover as much as 130 square miles (340 km2), twice the area of Washington, D.C. During eruption, these flows oozed slowly over the surface, moving at most a few hundred feet per day for several months to several years, destroying everything in their paths.....

The large magma reservoir beneath Yellowstone may have temperatures higher than 1,475°F (800°C), and the surrounding rocks are heated by it. Because of this, the average heat flow from the Earth’s interior at Yellowstone is about 30 times greater than that typical for areas elsewhere in the northern Rocky Mountains."
http://pubs.usgs.gov/fs/2005/3024/

Magma = hot spots? Have you ever been to Yellowstone to witness the hydrothermal fluid liquid mineral activity in the hot spots there?

 

Valich
I agree that there is a hot spot underneath Yellowstone. I should know- I have been working in and researching the Yellowstone system for over 15 years.

But that does not mean that a mantle plume exists beneath the Snake River Plain today. Certainly it did millions of years ago. The Yellowstone caldera and the Snake River Plain are two distinctly different geologic provinces, even if both were formed by passage of the Yellowstone hotspot.

If that were true, then every volcano on earth would be a hot spot.

There is only one "hot spot" at Yellowstone- whether deep or shallow mantle sourced- it is situated beneath (or very close to) the Yellowstone caldera and is responsible for the reservoir of magma there. This is the point source I am referring to, even if it is 70 km by 40 km in area.

I grant you that within this system there are several seperate (hydro)thermal basins- the most famous being the Upper Geyser basin, even though Norris is hotter and more acidic, and Hot Springs basin is quite a bit larger. The thermal basins are not separate hot spots, rather they are parts of the Yellowsone volcanic system, which is driven by a single hot spot (again I use the term "hot spot" in a tectonic framework- not a spot where localized heating has occurred).

 

I am also using the term "hot spot" in a tectonic sense - not as a "single point source" in isolation from the underlying and thermal-interconnected magma chamber.

The Yellowstone caldera sits over a huge magma chamber that is just a few miles underneath it and is pushing this caldera upwards. The Snake River intertwines its way through Yellowstone and across the SNP and there are hot springs all along it in Wyoming and Idaho: the source of these hot springs are ultimately the same. There is a huge magma plume under Yellowstone that extends into Idaho. The Snake River is dotted all along the way. Faults, fractures and thermal interfaces allow thermal transitions of this huge pool of magma. Yellowstone is on a giant volcanic crater and hot magma is just a few miles underneath, but the plume is huge and not confined to just Yellowstone.

"The Snake River Plain traces the path of a geologic hot spot now centered in Yellowstone National Park." http://en.wikipedia.org/wiki/Snake_River_Plain

"At the heart of Yellowstone's past, present, and future lies volcanism. Catastrophic eruptions occurred 2 mya, mya, and then 600,000 years ago. The latest eruption spewed out nearly 240 cubic miles of debris. What is now the park's central portion then collapsed, forming a 28- by 47- mile caldera (or basin). The magmatic heat powering those eruptions still powers the park's famous geysers, hot springs, fumaroles, and mud pots. In the last decade, geological research has determined that the two volcanic vents, now known as "resurgent domes", are rising again."
http://vulcan.wr.usgs.gov/LivingWith/VolcanicPast/Places/volcanic_past_yellowstone.html

"The Yellowstone Hot Springs: How They Work
As ground water seeps slowly downward and laterally, it comes in contact with hot gases charged with carbon dioxide rising from the magma chamber. Some carbon dioxide is readily dissolved in the hot water to form a weak carbonic acid solution. This hot, acidic solution dissolves great quantities of limestone as it works up through the rock layers to the surface hot springs. Once exposed to the open air, some of the carbon dioxide escapes from solution. As this happens, limestone can no longer remain in solution. A solid mineral reforms and is deposited as the travertine that forms the terraces." http://www.nps.gov/yell/nature/geothermal/mamterrc.htm

"The volcanic history of the Yellowstone-Snake River Plain volcanic field is based on the systematic time-progressive volcanic origin of this region that is characterized by several large calderas in eastern Snake River Plain with dimensions similar to those of Yellowstone's three giant Pleistocene calderas. Earthquakes in this area [West of Yellowstone all the way across to Central and Southwest Idaho] are part of the divergent belt of seismicity that extends more than 400 km along the west side of the SRP in a west-southwest direction into central Idaho....While there is no systematic time progression of the Columbia Plateau basalts, the immense scale and synchroneity of timing of this volcanic field suggests a similar mantle source for both Yellowstone and the Columbia basalts."
http://www.mines.utah.edu/~rbsmith/RESEARCH/YellowstoneHotspot.html

 

In other words, as the last article states: "a similar mantle source for both Yellowstone and the Columbia basalts."

There are hot springs all along the Snake River that extends from Yellowstone into Central Idaho to Southwest Idaho. Either part of this same magma plume lies underneath this entire area, or there are underground faults, cracks, and crevasses that still transmit pockets of magma under Idaho or somehow transmit heat to form these hot springs in Idaho from the same source. My guess would be that this magma plume is so huge that although it is now centered under Yellowstone, it has been spread out by its pathway and is now much smaller or thinner or deeper there. How else can you account for so many hot springs all over Idaho in the wake of the path of the same magma chamber?

 

Valich
I think we are arguing semantics.
We agree that Yellowstone Park (and by extension-Yellowstone caldera) sits atop the present Yellowstone hot spot.
We agree that the Snake River Plain is the path of the hotspot.
We agree that there is a time-progressive sequence of volcanic eruptions (magmas) from southwest to northeast along the SRP.
We agree that the present Yellowstone volcanic (magmatic) system produces, among other things, the spectacular hydrothermal features that are renowned in Yellowstone.

Looks like our only point of disagreement is whether or not the present hot spot extends beneath the SRP.
Hot spots throughout the world display some common characteristic features:
1. Regional tumescence or uplift. This is obvious in Yellowstone Park- in contrast, the SRP is subsiding. Not surprising that as the hot spot passes through the uplifted rocks then cool, densities increase, volume decreases and subsidence takes place.
2. Low seismic velocities. As expected, the lowest seismic velocities in the region are beneath Yellowstone Park. SRP seismic velocities show a marked increase over those found below Yellowstone Park. Though the seismic velocities in the SRP are greater than those in Yellowstone, they are lower than the continental rocks bordering the SRP to the north and south, suggesting thermal disturbance in the past.
3. Active seismicity. Yellowstone is seismically very active. In contrast, the SRP is almost aseismic.
4. Waning volcanism. The change from a predominantly rhyolite system in Yellowstone to a predominantly basalt system in the SRP also argues that the hotspot no longer underlies the SRP. As the SRP cools and contracts, the low-viscosity (probably mantle derived) basalts can more easily make their way to the surface.
5. Heat flow. All hot spots are characterized by high heat flow, usually in the order of 30 to 40 times the crustal average. Yellowstone’s heat flow fits in this range- heat flows in the SRP, while still above crustal averages, are almost an order of magnitude lower.

You pointed out the “so many hot springs all over Idaho” as evidence for a much larger hot spot/magmatic system. There are hot springs located all throughout the western United States- including New Mexico, Arizona, California, Nevada, Utah, Colorado, Wyoming, South Dakota, Montana, Idaho, Oregon and Washington. Surely you don’t suggest these are all related to the Yellowstone hot spot? Or some other hot spot? The three components needed for hot springs (water, heat and a plumbing system) do not even make a magmatic system a necessary component.

Are the Miocene Columbia River Basalts related to the paleo-Yellowstone hot spot? Possibly. I hope you’re not suggesting that present Yellowstone hot spot still underlies the Columbia River Basalts.

At any rate, this is getting way off-thread. My point is that there are no Yellowstone type “hot spots” in the Himalayas. Is there magmatic activity? Of course. Are there hot springs? Of course. But magmatic activity and hot springs do not necessarily equal “hot spot”.

 

We are not in disagreement at all - semantics or otherwise. We are having a very rational intellectual exchange of information and you have provided an excellent counter theory to my suggestion that a magma area still must somehow exist in Idaho to account for so many hot springs there:

"4: As the SRP cools and contracts, the low-viscosity (probably mantle derived) basalts can more easily make their way to the surface.
5. Heat flow. All hot spots are characterized by high heat flow, usually in the order of 30 to 40 times the crustal average. Yellowstone’s heat flow fits in this range- heat flows in the SRP, while still above crustal averages, are almost an order of magnitude lower."

Basically, I think I stated the same, i.e., "probably mantle derived." But I'm thinking that these are remnants of leftover magma or "faults, cracks, or crevasses" that still allow small portions of magma to protrude through, or still supply a way of thermal convection.

You state: "Though the seismic velocities in the SRP are greater than those in Yellowstone, they are lower than the continental rocks bordering the SRP to the north and south, suggesting thermal disturbance in the past."

This I did not know, nor understand. But there was a large earthquake that extends as a uplift North-to-South in Southcentral Eastern Idaho. It's quite famous as a tourist attraction there along that area and appears as a long uplifted fault about 2-6 feet high on the Eastern side.

 

I assume you're talking about Quake Lake, formed durning the 1959 Hebgen Lake earthquake.

Have you visited Yellowstone? Have you also had a chance to tour the Snake River Plain? Fascinating geology.

 

No, Quake Lake is in Montana just west of West Yellowstone. Brrrrr. Had to run outside to my truck to get my map of Idaho. It's about 15 degrees here in Flagstaff - hope that darn magma chamber moves south here for the winter!

You'd have to look on a map but there was a huge earthquake that caused a long fault that goes linear Northwest-to-Southeast about 150 miles Southwest of Yellowstone. So this obviously was due to the movement of the plate over this magma chamber because it is uplifted on the Eastern side. It runs all the way down parallel to I93 from Chialis, Idaho, where I93 branches off to R75, to where I93 ends in the Southeast at Arco and Buttte City, Idaho: remnants of the past.

To the immediate North of this equarthquake ridge there are numerous hot springs between Stanley, Idaho and Salmon, Idaho along R75 to North I93, directly west of Yellowstone. There are three large hot springs that rise up directly into the Snake River just east of Stanley, but hot springs extend all the way from Hell's Canyon, where the Snake River then merges with the Salmon River in Oregon, to the origin of the Snake River in Yellowstone.

There are hotsprings all along the way from Boise to Stanley to the east. So where is this thermal uplift coming from? Lingering hot pockets (not necessarily socalled "hot spots"), or a direct thermal convection still existing through faults, cracks, or crevasses from the original magma chamber now huddling over Yellowstone?

 

Remember you are dealing with the Idaho Batholith (Cretaceous to early Tertiary) as well as Eocene volcanic and intrusive rocks throughout much of that area. Too old to be related to Yellowstone, but young enough to still produce hot springs. Most of the hot springs in this area are found along faults that probably tap deeper geothermal reservoirs.

Are you referring to the Borah Peak earthquake (shook bricks off buildings in Challis) in the early 1980's? Left quite a scarp and is oriented more N-S?

 

Yes, In fact the Idaho Batholith (formed through a series of phases, 40 to 100 mya) underlies even the Snake River Plain and beyond it to the South. But it dips down under the SRP, with the SRP on top of it: like a basin. The Idaho Balolith's 20,000 square miles underlie almost all the mountain ranges in Idaho: North, Central, and South.

The hot springs I was referring to east of Stanley are in the Salmon River: not the Snake River, but there are hot springs all through this area as well - all across Central and Southern Idea. Some of them are mineral hot springs and smell of sulfur: a clear indication of magma below. These are all along fault zones. The Salmon River follows a suture.

The earthquake that I was referring to is the 1983 Borah Peak Earthquake (7.3 on the Richter) that is just west of the Lost River Range and was centered just south of the Borah Peak (the highest peak in Idaho, elev. 12662 ft.). The Lost River and Lemni Ranges both run parallel to the Bitterroot Range and are part of the Idaho-Montana Thrust Belt: lots of fault-related folding, including the basin-range faulting from the SRP formation.

A great photo of the 1983 earthquake scarp and the Borah Peak can be seen at:
Maughan http://www.forwolves.org/ralph/wpages/borahpk.htm

It is interesting to note that the Bitterroot and Lost River Ranges are actually part of an older orogeny system called Sevier Orogenies that were formed 150 mya when an ancient plate (now totally subducted) called the Farallon oceanic plate collided with the North American Plate. But lot's of very complex faults, folding, and errosional activity followed. http://home.att.net/~goggallery/frames/geology2.htm

"The Bitterroots expose rocks that formed in the earth's middle crust at depths somewhere around 20-30 kilometers (12-18 miles) below the surface, 90-50 mya, when Western Montana was part of a mountain range (known as the northern Sevier Orogen) more like the Andes, much higher and more extensive than it is today. 50 mya, the Sevier Mountains were torn apart by the extension or thinning of the continental crust. As the earth's crust thinned and the mountain belt collapsed, portions of the middle crust were transported upward to the surface on very large faults that are well exposed in a flank of the Bitterroot Range." http://clasnews.clas.ufl.edu/news/clasnotes/9910/

Another interesting fact is that the current magma chamber over Yellowstone is definitely a magma plume originating out of the Earth's outer core. This is evident by the fact that the Snake River Plain forms an arc 400 miles long and is dotted with volcanic activity, faults, and thermo-uplifts and hot springs. The Craters of the Moon National Monument is covered with 100 mile long stretches of lava and has cinder cones just 30-40 ft. high that errupted only 2,000 years ago. Compare that to the much earlier erruptions in Yellowstone. Also, basalts found on the Northwest part of the SRP are younger than those found in the Northeast part of the SRP. Therefore, the underlying plume must have formed - or still be forming - multiple magmatic chambers (hot spots) and not just the one now over Yellowstone. The 1983 Borah Earthquake is just 50 miles due North of Craters of the Moon Nat'l Mon.

"A hot spot provided the magma for the eruptions at Craters of the Moon. The Great Rift provided the pathway for the magma to reach the surface. The Great Rift is the most extensive of several volcanic rift zones which traverse the Snake River Plain. Volcanic rift zones are weak areas where the Earth's crust has stretched and thinned and fissures have developed. Magma under pressure follows these fissures to the surface. The Great Rift, which passes through Craters of the Moon, is 60 miles long and from 1-1/2 to five miles wide. It is characterized by short surface cracks, more than 25 cinder cones, and is the point of origin for over 60 lava flows."
http://www.nps.gov/crmo/hsg2.htm

 

Valich- While the main theme of your post is accurate, some of the wording is a bit confusing.

Magma is not necessary to produce a sulfur smell in hot springs.

The thrust faulting and folding occurred during compressive tectonics; Basin and Range faulting is extensional. The two are not related, except that they deform the same rocks. Also, SRP formation did not cause basin and range faulting, even though they are probably both related to the passage of the Yellowstone hot spot

Not totally subducted- remaining parts of the Farallon plate are called the Juan de Fuca, Rivera and Cocos plates and still exist off the coast of North America.
http://pubs.usgs.gov/publications/text/Farallon.html

First, I assume you meant "mantle" plume. Second, there is quite a bit of controversy over the source of the Yellowstone Hot spot. One group of geoscientists believes in a deep mantle source (beginning at the core-mantle boundary), but significant evidence now supports a very shallow (base of the crust) origin- leading the other group of Yellowstone researchers to refer to the Yellowstone heating anomaly instead of hot spot.
The first Yellowstone eruption is located along the Nevada-Oregon boundary- at McDermitt caldera. While the time-progressive sequence of volcanism from McDermitt to Yellowstone is well-publicized, there is a less well-known "sister" track, a time-progressive sequence of volcanism that also begins in McDermitt, trends northwest and ends at Newberry Caldera near Bend, OR. Hard to explain with a deep mantle plume.
Much of the hot-spot origin discussion is like the old chicken and egg argument: did the hot spot cause the extensional tectonics, or did the extensional tectonics create the heating anomaly?
Third, I hope that the magma chamber is "under" Yellowstone, rather than "over" it.

The hot spot, or "underlying plume" is beneath Yellowstone. The SRP, which is the track of this hot spot, cools, contracts and allows the underlying molten basalt (mantle material) to finally make its way to the surface. In a few million years, when the hot spot has moved further to the NE, Yellowstone park will cool, contract, subside and be covered with basalt flows.