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dr_wu002
06-22-2005, 09:05 AM
Dr. Wu's girlfriend, Jess (incidentally the person who got me into hiking) is a geologist -- not This Geologist (2nd on the left, I believe) (http://fat-cat.co.uk/fatcat/images/artists/325/53_257.jpg) but she is one. And she's good to have on the trails because she can always answer my childish questions either about the landscape (is Mt. Washington a live or an extinct volcano?) or even biology (is this tree deciduous or carnivorous?). I really enjoy the landscape and what the mountains look like. In fact, I have a lot of the raised relief topo maps sitting near my desk at home and I often look at them.

However -- and this is something Jess hasn't been able to answer for me -- has anyone wondered or perhaps know of a study that has been done that imagines how The Whites looked before the last major glaciation? Before all the impressive valleys and cirques were carved? I imagine the mountains would be higher? Less rocky? More rocky? (Mt. Washington). I'm wondering if there exist any computer simulations that could draw an imagined 3-D topo of what the area looked like thousands of years ago. Any ideas? Any books to rec'd?

Thanks!

-Dr. Wu

lumberzac
06-22-2005, 09:17 AM
Funny that you mention this. I was thinking almost the same thing about the Adirondacks on the drive to work this morning. I was imagining what hiking up the Great Range or Giant would be like if before Keene Valley was filled with over 900’ of glacial debris. BTW one of my regular hiking partners is a geologist as well. I call him the Rock Nazi when he doesn’t shut up. :D

sapblatt
06-22-2005, 09:17 AM
The only thing I remeber from a college geology class was that these mountains were a lot higher in the older eras...not sure about anything else. Erosion, wind, glaciers, etc have made them all smaller. I also know that the Whites are considered to be a very old mountain range.

dr_wu002
06-22-2005, 09:21 AM
The only thing I remeber from a college geology class was that these mountains were a lot higher in the older eras...not sure about anything else. Erosion, wind, glaciers, etc have made them all smaller. I also know that the Whites are considered to be a very old mountain range.
Unfortunately I never took a geology class. I think everything is a pluton.

There are a lot of geologists in the North East... I wonder if anyone has done a computer simulation.

-Dr. Wu

sapblatt
06-22-2005, 09:26 AM
Unfortunately I never took a geology class. I think everything is a pluton.

-Dr. Wu

Isn't Dr. Daisypodiae a geologist? Thought I read that somewhere...

My geology class hardly ranks...it was basically the science class that you took if you were a non science person...we called it "science for business and phys ed majors!" It avoided the rigors of chemistry, biology and physics. The companion class, "weather and climate" was great...got a lot out of that one!

DougPaul
06-22-2005, 09:45 AM
A whole pile of links here: http://nhgs.org/GSNH/NHgeol.html.

Doug

ExploreTheEast
06-22-2005, 09:52 AM
I just like the phrase "Plate Tectonics." It's great to throw out in everyday casual conversation:

"If it weren't for these pesky plate tectonics, I wouldn't have been late to work this morning!"

mavs00
06-22-2005, 10:20 AM
Also, here is brief, but simplified (for dummies like me) site that contains some interesting facts and information about the basic underlying -Geology of the Adirondack Mountains- (http://gretchen.geo.rpi.edu/roecker/nys/adir_txt.html). Check out the INTRODUCTION site for a explination of the pre-glaciation (and even further back) lay of the land.

Has nothing to do with Wu's original question about the Whites :o , but perhaps some (like Lumberzac) may have simlar questions about the Adirondacks.

**NOTE** - I think the text is from a book, so it does reference figures or charts that are not with it. It did not seem to hurt the understandability of the story.

Puck
06-22-2005, 11:17 AM
I also know that the Whites are considered to be a very old mountain range.

Indeed. That is afact needed when dealing with the altitude snobs from out west. Thier peaks are new kids on the block!

dug
06-22-2005, 11:18 AM
From what I recall from my college Geology classes, the mountains were considerably higher. I believe they were talking 20,000'+/- (take that you Rockies fanatics!) They were more of a rounded mass than the peaks and valleys seen today. There wouldn't have been the rockpiles you see today, as those were left from retreating glaciers. Of course, with the erosion cycles, there were probably periods where they were rounded, eroded down to sharp valleys, then were worn down again to rounded...then eroded into sharper valleys again. After each ice age, the mountains would change and keep taking some "off the top" if you will.

The Appalachians are one of the oldest -if not the oldest- mountain ranges in the world. As you get north into Canada, you can see the age of the exposed rocks near the sea level that go back billions of years. In terms of hight as measured from sea level, this would be pretty hard to calculate I would assume as the level of the sea is much different from today.

Do I have any study to prove any of this? No....

jjmcgo
06-22-2005, 12:16 PM
Dug wrote: "There wouldn't have been the rockpiles you see today, as those were left from retreating glaciers."
Were the rocks at the top of Mt. Washington, the long scramble over boulders to the summit, left there by glaciers or is Mt. Washington one rock with a million fractures?

^MtnMike^
06-22-2005, 12:19 PM
The Roadside Geology Series books for Maine (by D. W. Caldwell) and Vermont & New Hampshire (by Bradford B. VanDrver) have a lot of information about the geology of the Whites.
The first few chapters of each book cover the geologic history of the state(s) from the first mountain building event up to the most recent glaciation.

^MtnMike^

Willie
06-22-2005, 12:37 PM
Dr wu002,

If you’re interested in communicating with someone that may answer your question, contact Woodrow B. Thompson at the Maine Geological Survey (Geologic Mapping Section - Glacial Geology). He’s familiar with research on glaciation in the White Mountains. His e-mail address is on Maine’s Geological Survey’s web page.

dug
06-22-2005, 03:47 PM
"Were the rocks at the top of Mt. Washington, the long scramble over boulders to the summit, left there by glaciers or is Mt. Washington one rock with a million fractures?"

Probably a little bit of both. Both, as the glaciers retreated they left their mess. Some of that mess may have been directly from Washington. Good point.

DougPaul
06-22-2005, 04:23 PM
Were the rocks at the top of Mt. Washington, the long scramble over boulders to the summit, left there by glaciers or is Mt. Washington one rock with a million fractures?
The regions of angular rocks of the same rock type are probably frost fractured Mt. Washington. Rocks that have been carried by a glacier tend to be rounded (or at least have the corners rounded off) and may vary in type (depending on where they have been carried from).

Doug

Seeker
06-22-2005, 04:28 PM
The regions of angular rocks of the same rock type are probably frost fractured Mt. Washington. Rocks that have been carried by a glacier tend to be rounded (or at least have the corners rounded off) and may vary in type (depending on where they have been carried from).

Doug

Yep--what Doug said.

Papa Bear
06-22-2005, 04:56 PM
"Were the rocks at the top of Mt. Washington, the long scramble over boulders to the summit, left there by glaciers or is Mt. Washington one rock with a million fractures?"The type of formation on the top of Washington (also Jefferson and Adams) is called "Felsenmeer" - a wonderful German word meaning "sea of rocks". They are caused by alternate feezing and thawing.

"Erratics", on the other hand are carried along by Glaciers and often deposited when Glaciers retreat. They stand out prominently from the sourounding terrain and are generally not on peaks. They often consists of rock type not found in the area where they lie - since in fact they came from somewhere to the north. Glen Boulder is an erratic. There's also a beautiful one in Arcadia National Park which you can't miss when you drive by just past Eagle Lake way up on the ridge.

forestgnome
06-22-2005, 09:33 PM
Madison Boulder, very near my home, is a huge erratic. It's worth a visit if you're really interested in them. It stands out dramatically from the surrounding terrain, looking very out-of-place. It's noted in the AMC Guidebook.

Dugan
06-22-2005, 10:06 PM
Glacial erratics are found throughout MA also.

According to a very good Geology 101 teacher from years ago - consider also that a curvy line traced from Long Island to Cape Cod is the terminal moraine of the last glaciers. Also that the glaciers were 1-2 miles thick, and that the majority of earthquakes in New England today - thousands of years later - are still the earth's crust rebounding from the pressure of the glaciers.

Also according to this teacher and the assigned text, the Whites were thought to have rivaled the Himalayas, since the orogeny that created each is similar. The instructor said that the Whites were formed the last time the continents all bashed together. They formed a land mass that's today called Pangaea. Likewise, the Himalayan mountains are forming as the result of two different plates with land masses on the edges being forced together (Australian-Iandian Plate being forced northward into the Eurasian plate), which is how the Whites would've been formed. I know of a link to a computer sim that shows the theoretical break up and formation of Pangaea, http://wrgis.wr.usgs.gov/docs/parks/animate/, but it doesn't include weathering that formed the Whites as we know them.

The USGS has an interesting site on earthquakes. It clearly depicts that the majority of quakes appear on the edges of tectonic plates. K2 may outpace Everest yet!

dr_wu002
06-23-2005, 07:41 AM
Thanks for the replies so far, everyone! This one is a little more complicated than the other things I posted yesterday regarding "alpine spiders" and "alpine zones." I'll comment more after someone named Rosinante posts some comments about Glaciation.

-Dr. Wu

dr_wu002
06-23-2005, 12:56 PM
I wonder if anyone can use the Hubble Telescope to look back and snap a few photographs of the Whites and what they looked like 12,000 years ago and beyond! If the Hubble can look at the universe a few seconds after the Big Bang then it shouldn't be too difficult to see a few thousand years ago on Earth!

-Dr. Wu

Rugger
06-23-2005, 01:41 PM
Concerning the rebounding of the New England crust. My geography prof. from UVM claimed that in several thousand (can't remember how long) years, if nothing were done at the Northern end, Lake Champlain would start to drain south because Norhtern Vermont was rebounding faster.

^MtnMike^
06-23-2005, 02:01 PM
I wonder if anyone can use the Hubble Telescope to look back and snap a few photographs of the Whites and what they looked like 12,000 years ago and beyond!


Unfortunately, no :( (that would be cool though! :))
In order to see something as it was 12,000 years ago the Hubble Telescope has to be roughly 12,000 lightyears aways from it.

^MtnMike^

DougPaul
06-23-2005, 02:31 PM
Unfortunately, no :( (that would be cool though! :))
In order to see something as it was 12,000 years ago the Hubble Telescope has to be roughly 12,000 lightyears aways from it.
Unless you can find a rather strong gravitational lens 6000 lightyears away. :)

But it would probably distort the image. :(

Doug

dug
06-24-2005, 06:59 AM
Still working on the kinks on my time machine. Last test subject I sent back I haven't heard from. If I get the flaw figured out, I'll be sure to let you guys know. Damn DeLoreans.....

jjmcgo
06-24-2005, 10:25 AM
Dear Papa Bear,
I Dogpiled felsenmeer and got this brief article on Torngats felsenmeer.
http://cgrg.geog.uvic.ca/abstracts/MarquetteStudiesOver.html

Here's a brief and interesting website on the geology around the Huts and it has links to other N.H. geological information.
http://www.coloradocollege.edu/Dept/GY/faculty/wphillips/web%20page.htm

I really enjoyed this thread and learned a lot.

So, felsenmeer is not synonymous with scree? It is one type of scree? Scree seems to define all loose rock, regardless of origin. Still trying to learn here.

Papa Bear
06-24-2005, 10:37 AM
So, felsenmeer is not synonymous with scree? It is one type of scree? Scree seems to define all loose rock, regardless of origin. Still trying to learn here.I'm not a geologist, but I would say "scree" is a generic term which refers to weathered material on slopes. Most often Scree is loose and fairly small grained (i.e. gravel) although the term is probably applies to a variety of surfaces. It's origin is most probably from erosion of running water, but some freeze/thaw weathering may play a part. In the Whites you would find "scree" on slides, e.g. the Lincoln Slide. In the Torngats it's probably more widespread since there are no trees.

I would say Felsenmeer is not a type of Scree since it is not loose (the rocks don't move) and certainly not small grained.

Interestingly this thread's title is "The Whites - Pre Glaciation". Felsenmeer is certainly a post-glaciation phenomenon and being above tree line, is likely to be fairly permanent. Scree OTOH, (excpt for morains such as Long Island and cape Cod) are probably very recent, and not permanent.

Eventually the scree covered slides and loose slopes get vegetated (maybe over a period of hundreds of years) and the scree will become soil. Of course new scree will form from new slides, new eroded areas (from logging, fires, etc.) and the cycle goes on.

Beyond that, I would say a geologist needs to chime in here.

Puck
06-24-2005, 11:53 AM
Speaking of skree...I have a question/observation. One effect of glaciation are the eskars. I understand that these can appear as a low ridge in a valley and are mainly comprised of gravel and breadloaf sized rocks. When I hiked Cannon I kept thinking that the lower part of the mountain, the loose gravel that has eroded out, cuold have been deposited by the same mechanism that forms eskars, a stream of melted ice flowing under the glaciar. Or it may have been formed like a morraine, left as the glaciar advances or retreats. My understanding is dunlins, eskars and moraine are made up of debris from glaciar and could be identical in composition, however, it is the mechanism under which they were formed defines them.

We could use a geologist on this thread.

dug
06-24-2005, 02:02 PM
A terminal morraine is at the end. Kind of like a snow plow. As the glacier advances, it pushed all the crud along. When it retreats, the morraine is what is left. There are morraines on the sides (can't remember what they are called).

When you have meltwater on a glacier, a stream will run underneath it. Kind of like a culvert underneath a road I guess. That stream is filled with debris, and when the water stops and the glacier retreats, the eskar is left over.

A drumlin, I THINK, is similar but bigger.

All are similar in nature, but I think the debris size will get bigger as you go from eskar to drumlin to morraine. For example, Long Island and Cape Cod are terminal morraines.

I can't picture the spot on Cannon you are referring to.

Rugger
06-24-2005, 02:07 PM
If I remember correctly, a drumlin is kind of like a bubble of debris (mud & rocks) being moved along under the glacier. When glacier returns North, the "bubble" dries out to become a cute little rounded hill.

dug
06-24-2005, 02:48 PM
Good description. A drumlin can be HUGE. The sand pit area visible behind the Burger King off I-93 Exit 24 is an example if I recall.

My college profs will either be:

a) Proud of what I remember, or
b) Extremely disapointed in me

:D

Puck
06-24-2005, 02:55 PM
An example of a dunlin that I have read about are the hills around Boston. Breed's Hill is one. Rugger, you explanation jogs my memory and it sounds right.

dug, I can stand on top of the basalt ridges in central CT and see the terminal morraine on Long Island. It is interesting that while New England was pressed under a glaciar, long island was...uh...dirt. I know morraines are formed by the glaciar pushing debris into piles which can occur in front of the glaciar and on the sides, as you said. There is also a morraine that builds up under the glaciar. I don't remember the term.

The place in Cannon is at the start of the trail from the ski area parking lot. The trail has high embankments of loose gravel on both sides. The trail seems terribly eroded. On other trails in the Whites erosion shows slabs of granite. The cannon trail is really unique. I thought that the gravel would be coveted by a construction company for fill. so happy the area is protected.

Willie
06-24-2005, 02:59 PM
You guys are doing pretty well without a geologist. What you really need is a glacial geomorphologist. I remember just enough of this glacial geomorphology stuff from graduate school to be dangerous - I studied structural geology. Nevertheless, to summarize some of the terms that have been used:

A “drumlin” is an elongated hill or ridge of glacial till. It’s not clear how they form or why they form in some places and not in other places. Wisconsin is the land of drumlins.

An “eskar” or “esker” is a long, narrow ridge of coarse sediment and gravel deposited by a stream flowing under a stationary glacier. When the glacier melts, the eskar remains in the form of a ridge.

A “moraine” is an accumulation of sand, gravel and other sediment and debris deposited by a glacier. A “terminal moraine” forms at the leading edge of a glacier (as stated, Long Island is a classic example). A “lateral moraine” forms along the edge of valley glaciers. I don’t know about New Hampshire, but if you hike in the Adirondacks and look along the valley sides, you can observe lateral moraines.

“Scree” and “talus” is an accumulation of loose/broken rock. If it’s at the base of a steep slope, some will define that accumulation as scree. If it’s at the base of a cliff, some will define that accumulation as talus. The slope at the base of the Trap Dike in the Adirondacks I call a talus slope.

“Felsenmeer” is an accumulation of frost fractured rock without a cliff or ledge above as an apparent source. The summit of Mount Washington is a good example.

Raymond
06-25-2005, 01:00 AM
Maybe you can find something on this lengthy page:

http://www.erudit.org/revue/gpq/1999/v53/n1/004882ar.html

I'm pretty sure there's an explanatory drawing displayed somewhere at Acadia National Park that shows that area pre- and post-glacier, but I can't find anything like it online.

Dugan
06-26-2005, 05:15 AM
From what I remember, Willie is correct, lateral moraines are more along the sides, and are found especially as ridges of till that parallel the sides of valleys.

Another type of moraine is the medial moraine, unique to alpine areas. They're formed when alpine glaciers merge to create a single glacial flow. The result is that the till formerly carried along the mergine sides become a single stream of debris within the new, larger glacier.

Cirques also are a result of glaciation. A cirque is a bowl shaped depression with steep walls upvalley, and an open end down valley. They're typically formed in a deep "v" shaped valley as snow and ice accumulate and begin to form a glacier. As it enlarges, frost wedging forms debris and the glacier gathers that and other debris into itself. The WMG says that Great Gulf is the largest cirque in the Whites.

Also related to glaciers - If you climb Watatic, you can see marks in the rock at the summit where it was scratched by debris pushed along under the glacier as it passed over.

DougPaul
06-26-2005, 10:57 AM
Cirques also are a result of glaciation. A cirque is a bowl shaped depression with steep walls upvalley, and an open end down valley. They're typically formed in a deep "v" shaped valley as snow and ice accumulate and begin to form a glacier. As it enlarges, frost wedging forms debris and the glacier gathers that and other debris into itself. The WMG says that Great Gulf is the largest cirque in the Whites.

Uhhhh... Glacial valleys are U shaped. (River valleys are V shaped.) A cirque is the head of a glacial valley.

Tuck, Ravine of Raymond Cataract, Huntington, and Great Gulf are all glacial. King Ravine, Jefferson Ravine, Madison Gulf, and Castle Ravine all look glacial from the topo.

Glaciers tend to form on the north and east side of mountains (less melting).

Doug

Dugan
06-26-2005, 10:21 PM
Yes, DougPaul, they are now "U" shaped. However, pre-glaciation, they were "v" shaped. As the glacier moves through, it rounds the v to a u.

DougPaul
06-26-2005, 10:40 PM
Yes, DougPaul, they are now "U" shaped. However, pre-glaciation, they were "v" shaped. As the glacier moves through, it rounds the v to a u.

Yes if the glacier is flowing down an established stream valley.

Doug

HikerBob
06-27-2005, 05:51 AM
There is some great info in section 17, pages 361... of FOTH regarding glaciers. Check it out. Great illustration on 362 explains a lot.

Bob

dr_wu002
06-28-2005, 08:02 AM
the Whites were thought to have rivaled the Himalayas, since the orogeny that created each is similar. The instructor said that the Whites were formed the last time the continents all bashed together. They formed a land mass that's today called Pangaea. Likewise, the Himalayan mountains are forming as the result of two different plates with land masses on the edges being forced together (Australian-Iandian Plate being forced northward into the Eurasian plate), which is how the Whites would've been formed.
Now I've heard this several times before (including from the geologist that I live with) and my question is, were the Whites these big, majestic mountains like the Himalayas or were they more a very high plain with large bumps on it? I'm trying to imagine something looking like the Himalayas being carved and whittled down into the small (but so loveable) White Mountains we know today. I realize that Pangaea was a long time ago (pre-civil war era, I think) and there have been many ice ages since then (?) which could have left their mark in the Whites but for me it's still very difficult to understand.

I'm a physicist (of some sorts... although most of those sorts are gone these days) and can understand some things but for some reason, glaciation is something that I find very difficult to imagine in my head. it's the time frame that kills me. I should go back to school for this stuff because A) I could understand it but B) and most importantly -- I'd get to move to Antarctica or Greenland or something and be freezing cold all the time! :p Bring it on!

-Dr. Wu

dr_wu002
06-28-2005, 08:05 AM
the Whites were thought to have rivaled the Himalayas, since the orogeny that created each is similar. The instructor said that the Whites were formed the last time the continents all bashed together. They formed a land mass that's today called Pangaea. Likewise, the Himalayan mountains are forming as the result of two different plates with land masses on the edges being forced together (Australian-Iandian Plate being forced northward into the Eurasian plate), which is how the Whites would've been formed.

Another thing too we should consider is that The Whites are part of a larger Mountain Chain -- The Appalachian Mountains. I assume that during the existence of Pangaea, the entire Appalachian Mountain Chain was large & high. Now, what has happened to the Whites is somewhat different than what happened to say, The Blue Ridge Mountains -- less glaciation and whatnot (at least recently, I believe) but still, they are roughly the same elevation. Any insight anyone?

-Dr. Wu

diehard
06-28-2005, 08:17 AM
An interesting question…something a geo-morphologist, or Geo-Forensic specialist (is
there such a person) would probably be able to reconstruct.

Many of the rocks of the White Mountains are only 150 +/- 25 million years old. These are the young ones, which we all scramble across when we are in the Pemi, in the Moats, Baldface, or the Percys. Now, when we are in the Presidentials the rocks are a bit older, at around 400, give or take, million years old. (The European Alps are around 25 (?) million years old). The last period of glaciation, perhaps 13,000 – 15,000 years ago. There is a lot of geologic history which has gone on in these mountains.

I’ve often wondered how many periods of glaciation have there been in 400 MY? One certainly wouldn’t say they would have ceased during the emplacement of the White Mountain Magma Series (Conway Granite etc), as volcanoes are known to exits under glaciers, today. What are the mechanics of a moving sheet of ice, over a mile thick?

I believe, a good geo-morphologist, could look at the present day structure, the skeleton of what is left, and like a Geo-Forensic specialist, reconstruct what this area looked like 150 or 400 MY ago….but what do I know…………

Jim Cahoon

dr_wu002
06-28-2005, 08:22 AM
Many of the rocks of the White Mountains are only 150 +/- 25 million years old. These are the young ones, which we all scramble across when we are in the Pemi, in the Moats, Baldface, or the Percys. Now, when we are in the Presidentials the rocks are a bit older, at around 400, give or take, million years old. (The European Alps are around 25 (?) million years old). The last period of glaciation, perhaps 13,000 – 15,000 years ago. There is a lot of geologic history which has gone on in these mountains.
Like I said -- the time frame here kills me. 150,000,000 years vs. 400,000,000 years. A lot of thing can happen between in the 250,000,000 years in between. I find things that happen that incredibly slow difficult to imagine for some reason. It's almost like Geology is to the Earth as John Cage is to Music.

-Dr. Wu

TDawg
06-28-2005, 09:23 AM
This link may help in putting geologic time into perspective. I go to school for this type of stuff and geologic time is kind of a pain in the ass. But here is is....http://www.ucmp.berkeley.edu/help/timeform.html

My professor gave this link to my White Mountain Region and Landform Ananlysis classes as an aid. You can click on the epochs to see what was going on at that time in geologic history and evolution.

Also prior to the Mesozoic Era the Whites were under an ocean and as the continents collided to form Pangea, the sediments laid down by rivers at the bottom of the ocean and formed into rock, were thrust upward and rose above the sea around 250 mya. maybe. The "Littleton Formation" is what NH predominatly rests upon and the rocks in the Presidentails are of the Littleton Formation. These were ocean sediments that formed into rock under pressure and thrust upward. The top of Mount Washington is the upper part of the formation (mica schist and quartzite) and other parts of the Presies are the lower part of the formation (gneiss). These rocks are metamorphic due to the intense heat and pressure that resulted from the continents colliding.

Anyways, I'm not much of a geologist either but I know a few things from my classes at Plymouth State. But that time scale site helped me make sense of it all so it might be of some worth to you folks as well.

Oh and by the way, I'm fairly new to this site, but it is growing on me like a fungus. :D

Sundog
06-28-2005, 10:01 AM
Well, Dr. Wu, I can tell you a little about the history of the New England and the Whites. It all started with Laurentia, or Proto North America. It was the core from which North America as we know it grew. Around 450 million years ago a chain of island arcs collided with Laurentia in an event known as the Taconic orogeny. Prior to this orogeny, the edge of Laurentia was the Hudson river valley. The Taconic island arcs were accreted onto the Laurentian land mass as part of the continental slap subducted. Next came the collision with the Avalon terrane. Avalonia collided with Baltica (which later became part of northern Europe) and Laurentia about the same time. This event was known at the Acadian orogeny, and involved subduction of dense basalt from Avalonia to subduct under Laurentia. Such subduction was responsible for volcanism on the continent (think of the Cascades on the west coast resulting from the subduction of the Pacific plate under North America). Also, sediments from the Iapetus Ocean were scraped off and accreted onto Laurentia, along with arc volcanics and metamorphics from Avalon. This orogeny started roughly 425 million years ago. The terranes Laurentia, Avalonia, Baltica and later Siberia formed the land mass termed Euroamerica, which collided with Gondwana about 350 million years ago (I'll have to check my dates on this one) in an event called the Alleghenian orogeny, which uplifted the Appalachians even more. The much loved Pangea formed after Euroamerica collided with Gondwana. As Pangea splinter apart around 200 million years ago, the Atlantic began opening. As it did, Baltica and Siberia moved to form Northern Europe. The eastern part of Avalon was severed from North America and became Ireland, Wales, etc.

Geez, this is starting to feel like a term paper...

Anyway, that's the story, in short. It's actually wildly complicated if you delve into the details of the rock types and structural formations. But to answer your question regarding the majesty of the Whites, yes. They were once very impressively high with great spines of mountain ridges stacking up against one another (imagine pushing a table cloth along the table to form bunched up ridges). I'll show you some geologic maps of New Hampshire and Maine so you can get an idea of how the mountains evolved.

One last thing. Just so you know how clever (or nerdy) geologists can be, in Greek mythology Iapetus was Atlas's father. The Iapetus Ocean was the precursor to the Atlantic Ocean. Neat!

TDawg
06-28-2005, 10:05 AM
There is also a morraine that builds up under the glaciar. I don't remember the term.

Puck, I think they are termed Ribbed Morraines

dr_wu002
06-28-2005, 10:08 AM
Well, Dr. Wu, I can tell you a little about the history of the New England and the Whites. It all started with Laurentia, or Proto North America. It was the core from which North America as we know it grew. Around 450 million years ago a chain of island arcs collided with Laurentia in an event known as the Taconic orogeny. Prior to this orogeny, the edge of Laurentia was the Hudson river valley. The Taconic island arcs were accreted onto the Laurentian land mass as part of the continental slap subducted. Next came the collision with the Avalon terrane. Avalonia collided with Baltica (which later became part of northern Europe) and Laurentia about the same time. This event was known at the Acadian orogeny, and involved subduction of dense basalt from Avalonia to subduct under Laurentia. Such subduction was responsible for volcanism on the continent (think of the Cascades on the west coast resulting from the subduction of the Pacific plate under North America). Also, sediments from the Iapetus Ocean were scraped off and accreted onto Laurentia, along with arc volcanics and metamorphics from Avalon. This orogeny started roughly 425 million years ago. The terranes Laurentia, Avalonia, Baltica and later Siberia formed the land mass termed Euroamerica, which collided with Gondwana about 350 million years ago (I'll have to check my dates on this one) in an event called the Alleghenian orogeny, which uplifted the Appalachians even more. The much loved Pangea formed after Euroamerica collided with Gondwana. As Pangea splinter apart around 200 million years ago, the Atlantic began opening. As it did, Baltica and Siberia moved to form Northern Europe. The eastern part of Avalon was severed from North America and became Ireland, Wales, etc.

Geez, this is starting to feel like a term paper...

Anyway, that's the story, in short. It's actually wildly complicated if you delve into the details of the rock types and structural formations. But to answer your question regarding the majesty of the Whites, yes. They were once very impressively high with great spines of mountain ridges stacking up against one another (imagine pushing a table cloth along the table to form bunched up ridges). I'll show you some geologic maps of New Hampshire and Maine so you can get an idea of how the mountains evolved.

One last thing. Just so you know how clever (or nerdy) geologists can be, in Greek mythology Iapetus was Atlas's father. The Iapetus Ocean was the precursor to the Atlantic Ocean. Neat!
Absolutely perfect! You sound like a geologist! :p

This is exactly what I wanted to hear and it almost sounds like a tale rather than boring geology! There's so much history in all this -- I really enjoy hearing about it and ever since I was a kid I've liked to look at drawings of Pangea and whatnot & wonder what they were like...

Thanks!

-Dr. Wu

Puck
06-28-2005, 10:16 AM
Anyway, that's the story, in short. It's actually wildly complicated if you delve into the details of the rock types and structural formations. But to answer your question regarding the majesty of the Whites, yes. They were once very impressively high with great spines of mountain ridges stacking up against one another (imagine pushing a table cloth along the table to form bunched up ridges). I'll show you some geologic maps of New Hampshire and Maine so you can get an idea of how the mountains evolved.

One last thing. Just so you know how clever (or nerdy) geologists can be, in Greek mythology Iapetus was Atlas's father. The Iapetus Ocean was the precursor to the Atlantic Ocean. Neat!

Crashing plates, table clothes pushed up into peaks....you must be a real hoot at a dinner party. :D I would invite you over

Sundog
06-28-2005, 10:40 AM
Crashing plates, table clothes pushed up into peaks....you must be a real hoot at a dinner party. :D I would invite you over

Well, I try to behave myself as much as possible...

dr_wu002
06-28-2005, 11:37 AM
Crashing plates, table clothes pushed up into peaks....you must be a real hoot at a dinner party. :D I would invite you over

Well, I try to behave myself as much as possible...
Yeah! She's too busy making sure Dr. Wu isn't misbehaving! :p If anyone is going to be smashing dinner plates and setting tablecloths on fire it's him.

-Dr. Wu

moonrock
06-29-2005, 12:55 AM
Hi All:

Wow what fun to see so much passionate curiosity (and mercifullly uncharacteristic lack of bad puns!).
Really enjoying reading these posts.

Few points:

ADIRONDACKS (the rocks) are about 3-4 times as old as the Appalachians. They were a previous episode of continental collision and mountain building - possibly with part of what is now South America - but also created some of the rocks found in the oldest APPS.

The original ADKS (Grenville Mtns) were worn flat to a plain, then covered by sandstone, limestone and other sediments, even before the APPS started. Then more dirt washed off the Taconics westward across NY State. Then off the Acadians. Then off the final Appalachian Chain as Africa collided. This, and the later stretching and separation from Africa, created most of the bedrock in New England,more than 100 million years ago. The basalt cliffs and dinosaur tracks in central CT and MA (and NJ) are a gift, from a rift valley similar to that in east Africa today.

Fast Forward: Mostly erosion in the northeast. But then, just a FEW million years ago, things got interesting again: 1) crust under the ADKs started to blister up and form the (new) High Peaks (out of rock that was once 15 MILES underground !), and later 2) climate started to fluctuate, as continents drifted into key positions (Antarctica on south pole, Central America joining NA and SA, Himalayas affecting global winds. Perhaps).

ICE AGES in the NE were a most recent development, starting about 1-2 million years ago (much older periods of glaciation are found, but in different parts of the world (southern Africa) and hundreds of millions of years separate).
Remember: 45 million years ago, long after the dinosaurs, redwood forests still grew north of the Arctic Circle (the stumps are still mummified - and flammible - today)!!!

Based on chemical evidence, continental glaciers (like in Greenland and Antarctica) advanced (and melted back) from Canada/Eurasia a couple of dozen times. Four most recent (or expansive) classic episodes have been characterized from soils in the US and Europe.

Glaciers were the sandpaper, the final sculpting tool. They (or more correctly their base load of rocks and grit - sandpaper requires sand) deepened and rounded the valleys. As a continental ice sheet they covered most - but maybe not all - of the mountains in NY and New England. Imagine standing on top of Marcy or Washington 18,000 years ago and seeing nothing but ice in all directions (except up)! The glacier was perhaps a mile thick in central NY, so ice pressure on the highest mountains may have been secondary to freeze/thaw breaking the rocks. But in the valleys and lowlands the effects were profound. And crustal depression/rebound was about a third of the maximum ice thickness.

During lesser periods, individual or coalescent glaciers occupied the valleys between peaks in the Whites (and the Adirondacks), remnants of which are seen in headwall cirques at Mt Washington (and Gothics and Basin - and also out west in Yosemite).

TILL: was plastered beneath a glacier. Under thick portions of a glacier (or ice sheet), the pressure kept the ground from freezing. This allowed the ice to move relatively unimpeded on a slurry of sand, clay, gravel, and/or boulders. But as you got near the thinner edge (or terminus), the glacier froze to the ground and was overridden from behind by advancing ice. The result was a conveyer belt of dirt and rock, ground up beneath, but then thrust up to the surface, to the ablation zone (where ice melted/evaporated at the surface and left accumulated dirt). This "dirt machine" is what allowed MORAINES to accumulate on Long Island, from material transported south. Interlobate moraines (like large-scale lateral moraines), between medium-scale lobes of ice, occur in eastern Massachusetts and form part of Cape Cod.

DRUMLINS are egg/wedge-shaped landforms, either ground/freeze-thawed from resistant bedrock, or till plastered and sculpted into place. Look at almost any mid-elevation topo map from New England or upstate NY, and you'll see them.

KAMES are stratified sediment that collected on ice along the walls of valleys, then collapsed as the ice melted. ESKERS, collapsed stream deposits mentioned earlier, often are connected to Kames. Look in the 5 ponds area of the upper Oswegatchie, NY

Other obvious features are beaches and clays from early post-glacial lakes like Lake Albany. The clays have a squiggly, gullied topography but the beaches are continuous, smooth slopes above them. Look east of Albany near Route 90.

Would love to expound more, but I'm spent. [It's pouring here too. Finally.]

Moonrock