Sunday, October 25, 2009

10-21-09 Will It Ever Clear Up?

It felt like it wasn't going to clear. I changed into warm, dry clothes and headed up to the summit with my camera and notebook. This is the famous sign everyone passes on all trails that lead up to the high peaks, those above 4700 feet, in the WMNF. I often wonder how many climbers stop and think about the message and allow it to sink in, or whether it's merely a curiosity. This sign's been in this exact spot since I was 14 years old and has seen a lot of weather. We both have.

The smaller of the two lakes of Lakes of the Clouds fame in the thick fog.

This is Littleton Mica Schist as it looks as 'felsenmeer'. On clear days with greater visibility it lives up to its German name, "sea of rocks", because the blocks of the mica schist cover vast areas of the Presidential Range north of Mt. Franklin and Mt. Monroe. It covers probably a little more than 60 percent of the total area of the northern peaks.

I need to do more research on the chemical and physical properties of the Littleton Schist but I do know that after lying for millions of years on the floor of the ocean for millions of years as highly compressed sedimentary formations it was metamorphized about 300 million years ago when most of New England was lifted up off the sea bed by compression from tectonic plate movements and collisions. Since the Littleton Formation is not igneous (volcanic) it doesn't fracture on straight molecular planes the way some igneous rocks do so the blocks are irregular and of random shapes and sizes. Few of the fractured rocks within the felsenmeer could be described as having having straight edges but are occasionally nearly flat surfaces. The crack in this mica schist block is pronounced. It is difficult to walk across the felsenmeer.

Felsenmeer as a term also applies to these 'fields' of smaller rocks, also pieces of the Littleton Formation. In this photo and the one below there is little consistency in the sizes of the stones. They're randomly sized and some are stacked on top of each other as if a stone wall fell down. It would be much easier to interpret these landscapes if we knew that the glaciers brought these rocks here or that giants once lived here and tossed them around for sport and then left them all here for later use.

Goldthwait and others researchers have theorized that the felsenmeer is post glacial in origin because it wasn't polished or gouged by the glacier. Goldthwait estimated that as much as 500 fet of pre-existing 'material', e.g rock, gravel, and soil, were removed from the White Mountains by the last continental glacier. That's a lot of stuff! Anyway, that meant the parts of the rock mantle that were left when the glacier ablated were, the part that became the felsenmeer, was no longer compressed either by 500 feet of rock ledge or 1000-2000 feet of solid ice bearing down on it. I'm curious whether this release of compression, or the compression prior to release, had anything to do with the mechanical aspects of the formation of the felsenmeer.

As the glacier melted during ablation enormous quanities of water were released that must have created impressive cataracts, rivers bigger than the Ammonoosuc, that leapt down the high peaks to the valleys. I'm curious, too, how that may have contributed to the formation and/or movement of the felsenmeer.

This is merely a close up of the rocks in the photo above.

This photo shows the irregular shapes as well as the irregular edges of the rocks. Some edges are rough while others are more rounded, or what we would call 'weathered' but the weathering of these is irregular. The various lichens crusting the surface of these rocks are another feature of the felsenmeer that is important to think about. These plants are a possible clue to the timeline of events in the formation of the felsenmeer.

I walked off trail and zig zagged up the cone looking for a good site to set up a long term research project that begin by mapping an area of felsenmeer exactly using GPS to see if anything moves over a long stretch of time. Goldthwait's use of photographic data is not really conclusive in the long run. Using a site near the Cog tracks, too, would create questions about research data and the possibilities of intervention by humans and machines. The photos give some meaningful information but certainly are not as reliable as more precise measurements.

In this photo you see the egg shaped rock that appears in the last photo where it looks like it broke and fell away from the ledge. This is taken at the bottom of the cone. There's not much slope so gravity is not a large factor. A few questions: did the egg shaped rock actually break away from the larger mass of parent rock and if it did why is it so rounded? If not, where did it come from? I can't answer any of the question, I'm afraid, but I'd like to be able to.

I went up the cone to within a 100 feet of the summit but the fog was more opaque and the daylight dimmer than 500 feet below. At any rate half way up the a gentle side of the cone the rocks were aligned differently than on the flatter sections of the mountain. Gravity is obviously a more noticeable factor here. A glimpse of this formations gives an impression that the rocks here have potential energy and not merely resting here for eternity. They look as though they're just resting before rolling again.
I'll end the exploration with this photo of all the rocks stacked up in a formation near the bottom of the cone and ponder how that happened. One image that comes to mind is popcorn as though the blocks all fractured at once, leapt in the air for a second and then came to rest in these kind of unruly positions. Tfahe phenomenon of the felsenmeer is fascinating from the standpoint that during all the summers I worked in the mountains, traversing this very spot thousands of times, I never thought about the rocks one bit except to hope that one wouldn't move in some way to pitch me off as I jumped from one to the other.

Had enough of the felsenmeer? coming down out of the cloud cap I was greeted by a different world then what I'd left an hour earlier. The sun felt like cashmere. The weather felt as though it might go all the way and clear completely and be a fine October day and I began to regret having to go down. That's Mt. Monroe with Lakes of the Clouds nestled at it's feet.

When I see these remnants of tundra I have to ask whether this is an ancient landscape, say 100 million years old, or, a fairly modern one, say under 11,000 years old or since the last glacial sheet ablated here. At any rate in this photo you see the Littleton Formation as ledge protruding above the 'lawns' of, in this case, bigelow sedge which are for the most part resting on a glacial till soil itsel a remnant of the glacier. I'm curios what it would look like if you could peel some of the felsenmeer including the small rocks from a good sized area in the northern Presidential Range. What is underneath all that rock? The lawns may be relatively recent, but it is likely that tundra existed here for ages before the last glacial sheet extended south. It would be interesting to measure some of the lawns precisely and discover whether they are changing in size on all axes of the individual plots and also in total area. Are they expanding outwards in some areas, staying the same, or shrinking and dying back?

This goes back to the question of the balsam fir that I constantly hark back to and the progress the fir has made at some higher elevation sites like Zealciff, Carter Dome and Mt. Hale. A number of articles from the early 1900s on the ecology of the White Mountains and Mt. Katahdin in Maine, suggest that eventually all the mountains in New Enland will be forested to their summits. This will occur, it has been theorgized, regardless of wind and other aspects of the weather we think of as limiting factors for growth, and that it is a natural, successional process. The lawns could be a fundamental step in that succession.

The larger of the two lakes where it lies at the foot of Mt. Monroe. The clouds moving in were the front runners of another storm system coming in from the west.

The smaller lake, again, with some weak sunshine on it. You can see the cloud cap on the the upper ridge extending towards the summit.

Lakes of the Clouds Hut.

Lakes again with a measure of the snow that drifted in. By mid-January the whole front yard will be a huge snow drift rising above the roof line.

As I began my descent clouds were still coming in at 5,000 feet and a higher layer was beginning to congeal.

The clouds around the summit often looked as though they were about to vaporize in the warmth of the sun but when I got down to the Cog station the cap was solid and about where it was in the morning.

Fall colors linger on Mt. Dartmouth (right) and, all in all, the light and clouds are still of the fall but you know it's not for long, that winter is almost here and it won't be long before we'll be able to ski down Ammonoosuc Ravine.

1 comment:

Kay said...

Hey Alex,
I've enjoyed your posts so far. The egg shaped rock is what I would call sub-angular. Most glacial erratics take on this shape. If it is an erratic and similar to the surrounding country rock it wouldn't have traveled far.
Besides wind keeping treeline where it is the short growing season is the dominant factor in the elevation of treeline. The Balsam Firs and Black Spruces don't have time to harden themselves for the winter temperatures that can hit during the late summer andearly fall.