glacial cirque on carter ridge?

[forestgnome]

While enjoying the Baldface Circle Trail on Saturday, I noticed something very interesting as I looked toward Mt Washington and the Carter Ridge. There seems to be a glacial cirque, very similar to Tuckerman Ravine, on the eastern slope of the Carters. Then I noticed that I was hiking on a ridge that also resembled the same thing. They are all very bowl-shaped, and all facing the same direction.

Are these also glacial cirques?

 

[dug]

Certainly looks that way. Because there is so much vegetation in the area, it's harder to see. Due to it's lower elevation (albeit slightly), maybe it's more rounded and eroded more than it's more famous neighbors?

 

[Ridgewalker]

Consulted the AMC map number five and found no formal name for any of the cirques.

 

[dr_wu002]

I'll ask the Geologist.

I shall ask Rosinante when I see her later. Perhaps we'll even get her to post.

-Dr. Wu

 

[grouseking]

Cirque-Like?

There are many areas in the Whites that have cirque-like formations. I think near Mt Tom is a good example. I could of sworn that is a glacial cirque there, but I don't know for sure. I'm curious as to if there are common characteristics or a cirque up there, like a tarn. Click here to check out some more interesting characterisitcs on cirques. My guess is, the formation up there is either cirque-like or a somewhat poor example. But I am curious now!

here is another link to documented cirques in new england and even new york
cirques Further down they list all the documented ones, which is cool. But I'm sure there are more. Enjoy!!
grouseking

 

[bill bowden]

Cirque on Goose Eye as well

There's a small cirque on Goose Eye where the Wright Trail climbs up the headwall. Cirques are supposedly (I'm not much of a geologist) formed by valley glaciers which gouge out rock to form a steep headwall and then leave the rock in some sort of terminal moraine in the bottom of the valley. There's another small one on Crocker in Maine besides the classicc on Mount Washington and Katahdin. For reasons beyond my comprehension the circues were supposedly formed before the continental ice sheet enveloped New England rather than after. There are unsubstantited claims that the valley glacier which carved the North Basin on Katahdin remains today well hidden an insulated by the rock cover over it.

Maybe someone who knows more than I can tell us how to tell a cirque from your basic ravine by inspection on the ground or by map.

 

[injektilo]

Cirques are formed primarily due to frost wedging and are often associated with glaciers because the processes that form cirques are common geologic processes in glacial regions... therefore, a cirque is not always derived from a glacier. Small cirques are excavated beneath snowbanks even where no true glacier exists... snowbanks can grow into glaciers and large cirques are almost entirely the result of glaciers.

My undergrad degree was in geology though I haven't studied true geology in some time... I'm an environemtal consultant who deals mostly with groundwater... so any real geologists feel free to school me in glacial geomorphology.

grouseking - that looks like an interesting paper you linked to. I'm going to give it a read tonight.

 

[forestgnome]

Very cool! Thanks for replies and links.

 

[patrickbrusil]

I officially know more about Glacial Cirques than I could have ever hoped. Yet again I am in awe of the collective knowledge on these forums.

 

[chuck]

I have been up to Redrock pond a couple of times and I would say the area around it is a cirque.

 

[Dr. Dasypodidae]

I agree that the basin in which rests Redrock Pond might be a cirque, as technically a cirque should have a over-deepened or at least flat floor, with a bedrock outer lip being ideal. However, many definitions allow for less well-defined attributes, such as just steep headwalls and sidewalls. I wrote a paper on cirques in the Northeastern USA back in 1999, and can send a .pdf if you send me a PM.

 

[moonrock]

That's a nice reference about cirques in the NE.

I have a hard copy of a line-drawn map detailing known and "suspected" cirques in the Adirondack High Peaks region, and their relationship to the peaks and major valleys. But I cannot recall the source.

As far as alpine vs continental glaciation goes, they can happen at the same location at different times during an ice age (think "waterfall" vs. "flood"). The four "classic" glacial periods (Nebraskan, Kansan, Illinoisan and Wisconsin) and their european equivalents are merely extremes in a long-fluctuating series of major and secondary glacial advances and retreats. Before a continental sheet invades, and flows around and over mountains, alpines can grow, coalesce and invade surrounding lowlands, and linger after a major retreat.

You can have ice covering a good part of Canada, and alpine glaciers sprouting at high elevation in more southerly latitudes. It's partly the annual temperature balance (and snow budget) but also dependent on the amount of moisture available in any given region. Likewise, large continental glaciers tend to gain most within a few hundred miles of their margins - further "inland", it's too cold and dry (think interior Antarctica, with its scant inches of snowfall). So ice flows fastest toward the edges (they taught me, in 1983.....).

BTW, did anybody catch last night's NOVA program on the Channeled Scablands of Washington (produced by massive floods from a collapsed glacial lake) ? Makes the historic geologic community look like a buncha conservative white guys, but also illustrates how scientific paradigms (eventually) change with accumulation of evidence.

Moonrock

 

[Dr. Dasypodidae]

I would like to see the cirque reference for the Daks, as my impression has always been that much of that area is incised by glacial through valleys, leaving beheaded a lot of potentially fine cirque headwalls. In my 1999 cirque paper, I did include the cirque on the northeast side of Whiteface, and one in the Catskills that has the only bonafide alpine glacier moraine within the confines of a cirque basin in the Northeast.

Over the past three decades or so, we have learned from deep-sea sediment and icesheet cores that there were upwards of 18 to 20 glaciations of the magnitude of the traditional four orginally defined from our Midwest and in Europe. We have also learned that these glaciations terminate abruptly, with snowline rising rapidly enough to preclude re-occupation of cirques with alpine glaciers during the waning phases of continental glaciations. So, we conclude that alpine glaciers must form and erode their cirques during the buildup phases of continental glaciations, before being overwhelmed, as noted in the post just above. Some cirque erosion may also occur by continental ice in special circumstances.

 

[moonrock]

Guess I was thinking, in general terms, of alpine glaciers persisting (on earth) during interglacials. However, vacancy of cirques in the Dacks after regional retreat makes sense, for the reasons Dr. Dasypodidae indicated. Plus, we're (obviously) not talking about the Himalayas here.

Dr D: That reference I mentioned might go as far back as FLINT !!! I have it cut out and taped into the back cover of Jaffe, but no source. It stated that valley glaciation possibly occurred "in the late stages of Wisconsin deglaciation, after the ice sheet had backed off the mountains". Guess that's dated.

Been 22 years since I got my MS at Rensselaer, studying glacial geology, glacial aquifers and hydrogeology. Still a geologist/hydro by trade, but love to hear the details of more recent field research. And, since I work in (and for) NC, I have to drive up to the VA mountains just to see till (uh, make mine "Til-LITE").

I am familiar with the oxygen isotope studies, their correlation with Milankovich earth-orbital variations and the large number of implied glaciations (did an undergrad paper on that). I imagine that's standard instruction now, since ol' Milutin has held up so well.

But it's interesting that the "final four" major glaciations are the "only" ones well represented in the northeast US, implying that they collectively occluded all previous - and therefore less extensive ? - events. OTOH, I remember a (very WET) field trip, where Yngvar Isachsen described relict (Tertiary?)saprolite found in an Adirondack location. So glacial advance doesn't grind away everything unconsolidated.

There do seem to be plenty of "headwall" like features in the 46. And I wondered how those leanto sized boulders on Pitchoff were actually emplaced - skimmed Jaffe but didn't see mention........

[I NEED TO VISIT NYS - SOON !!!]

Moonrock