From Hudson Valley Magazine:
Ice Age in the Hudson Valley: A Geographical History
When you or I stand upon the great lawn at the
Vanderbilt Mansion
in Hyde Park, we picture ourselves living the grand lifestyle of fin de
siècle Hudson Valley aristocracy, of opulent balls and market-rigging
business deals held amid the stunning landscape of river and mountains.
When Johanna and Robert Titus stand on that same lawn, they picture
something a bit different. In their minds’ eye, they are knee-deep in
water, at the edge of a vast lake that stretches from the middle of the
eastern Valley counties to the middle of the western ones, and from
somewhere near Glens Falls all the way to the Atlantic Ocean (which is
about 100 miles further out and 400 feet lower than it is now). The
couple also envisions gigantic glaciers, which cover the continent from
mid-Long Island, through Chicago and Omaha, to the Dakotas, Montana, and
the Great Northwest — and are in the process of melting back to the
Arctic.
The Tituses, you see, are standing at the Vanderbilt Mansion circa
15,000 years BP (the geological term meaning “before present”). Robert
has a Ph.D. in geology and teaches at Hartwick College; Johanna has a
master’s in molecular biology and teaches at SUNY Dutchess. You may know
them as columnists for
Kaatskill Life and other newspapers. They recently published a delightful book called
The Hudson Valley in the Ice Age: A Geographical History and Tour
(Black Dome Press, $17.95). Part popular science, part travelogue, it
is that rare science book that is both challenging and entertaining.
Readers learn about arcane geological formations like moraines, alluvial
fans, and rock drumlins. Better yet, they discover where to find the
remnants of these formations via hikes and drive-bys at dozens of easily
accessible spots around the Valley. Consider these locales postcards
from the ice age.
We asked the Tituses to pick a handful of their favorite locations
where interested parties can launch their own geological time travel.
Once you start, our beautiful Valley will never look quite the same
again:
The floor of glacial Lake Albany
That’s what the previously mentioned lake is known as, and the site of
the Vanderbilt estate is just one of many places where you can easily
imagine the soft, flat lake bottom. “Get used to the idea that anytime
you see flat landscapes, you may well be literally on the floor of the
lake,” Robert says. The thruway south of Kingston, for instance, was
built on such a flat stretch of land, which is the result of deposits
left behind as mud on the floor of the lake. “Flat isn’t all that
interesting, until you realize you are at a lake bottom,” he says.
 FDR’s Springwood is perched on the edge of an ice age delta
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North Lake The area’s many lakes and rivers are all
remnants of the Hudson Valley glacier, which preceded and then was
overridden by the Laurentide Ice Sheet that covered all of the northern
reaches of North America. As the ice advanced, it left scratches in the
rock, called striations. One of the best places to find these is along
the eastern shore of North Lake in Haines Falls. “Look at the bedrock at
the edge of the water, and you’ll see the footprints of glaciers,”
Robert says.
The Kaaterskill Clove When deltas, like the one the
Vanderbilt Mansion sits on, are carved into gorges by rivers, they are
called cloves. In the Catskills, the Kaaterskill Clove — which contains
Kaaterskill Falls and the Red Chasm — is an example of this; at its
bottom is Palenville, which sits on a formation known as an alluvial
fan. Streams from the retreating glacier all headed into this delta in a
fan-shaped formation, cutting through rock, sand, and clay to create
the landscape. Johanna recommends that you stop at Red Chasm. “This is a
really scenic spot — many use it to swim — and you can really see how
the waters from the melting ice carved the canyon,” she says.
What’s most important about this site, the Tituses say, is that this
landscape carved by melting glaciers became the touchstone of the Hudson
River School of Art. “Thomas Cole painted his first paintings there,
and they figure so importantly in the cultural history of the Hudson
Valley,” Robert says. “And that all comes out of the ice age.”
 The High Falls spillway in Greene County once drained a glacial lake
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The Mansions The big houses built on the eastern edge
of the river, including Vanderbilt Mansion and FDR’s Springwood, are all
positioned on ice age deposits at the bottom of glacial Lake Albany.
Hyde Park rests on one of the lake’s biggest deltas, and the mansions
sit on the crest of that delta. “The aristocracy didn’t know it, but 150
years ago [when they were building their mansions] they were following
the path of the glaciers,” Robert says.
They also didn’t know that one day, their houses might slip toward the
river valley. The houses are not built on bedrock; they sit on soft
sediments like clay. Whenever you hear of a home damaged by a landslide,
usually after a heavy rain, it’s the result of land like this sliding
down the slope of the prehistoric lake bed. “The sediments are very
prone to landslides,” Robert says. “We have met people who lost homes
that slid downhill, and we have visited homes to evaluate their threat
of slides and had to tell them they were threatened. It is a present
danger anywhere in the Valley where these deposits exist.”
The Tituses say they have seen evidence of the bigger mansions
installing new drainage systems to shore up the grounds on which they
sit. “But there is no way to know when a landslide might happen,” Robert
says. “It could be 1,000 years, or 10,000 years, or in March if we get a
lot of rain.” He doubts the latter, though. “The land has been there
15,000 years, so I don’t think there is an immediate threat.”
 Patterson’s Pellet in Minnewaska State Park, a glacial erratic
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The Pine Bush These days, the Pine Bush Preserve in
Albany County is a foliage-covered plot of hilly, sandy soil. Just after
the glaciers retreated, though, it was a small desert not unlike
something you’d see in
Lawrence of Arabia. “All that was
missing were camels,” Robert says. The sand was blown in from what is
now Schenectady County, which then was one of Lake Albany’s biggest
deltas. As the lake retreated, the sandy deposits at its bottom were
blown by the west winds and dropped here, forming the dunes and swales
that have since been overgrown. “Stand on top of the dunes and imagine
what the area looked like 12,000 years ago,” he suggests.
There are many more spots where you can pick up the ice age trail.
Along their upper edges, the Shawangunks reveal erratic striations left
by the passage of ice. Frederic Church’s Olana near Hudson sits atop a
rock drumlin, a hill shaped like an inverted spoon bowl, which is a
signature of glacial advance. “Each location has its own chapter. We
suggest you pick up the book and go see what we saw,” Robert says,
“because it is an autobiography of our great adventures.” Adventures
that can take you to the dawn of your own homeland.
Speaking of ice...
The Tituses discuss their book at:
• Mine Kill State Park at the Power Authority. Off State Hwy. 30, North
Blenheim. Feb. 2, call for time (weather permitting); 518-827-6111
• John Boyd Thacher State Park Nature Center. 87 Nature Center Way, Voorheesville. Feb. 23 at 2 p.m.; 518-872-0800
•
The Albany Institute of History and Art. 125 Washington Ave., Albany. March 10 at 2 p.m.; 518-463-4478 or
www.albanyinstitute.org