~ ROCHESTER'S HISTORY ~
AN ILLUSTRATED TIMELINE
- THE PINNACLE RANGE
- 20 acres of Ellwanger & Barry's Nursery, adjoining the city reservoir, donated to city for park. Design by landscape architect Frederic Law Olmsted focused on horticultural. E & B donate rare trees and shrubs.
- Sept. 29, Children's Pavilion on hilltop is dedicated.
- Planting of several thousand flowering shrubs begins.
- John Dunbar from Long Island is hired as a full time horticlturalist.
- Anonymous gift (by Walter Duffy & George Eastman) enlarges to 150 acres.
- May lilacs draw 3,000 visitors to the 22 acre garden. News of the spring show is spread by word of mouth, there had been no announcements.
- Bobsled runs open.
- Highland Park Conservatory opens.
- Lilac Festival Committee takes over Lilac Sunday promotion
- Frederick Douglass statue moved from downtown (Central Ave. / St. Paul St.) to Highland bowl (near his home)
- June 11, GAR pageant for James A Hard, Rochester's last Civil War vet, 13,000 attend.
- When Oak Country Club is built, they removed a large hill from the site. It had been a popular sledding site for years. The steep hill got you sliding fast, then you were flung out onto the ice covered river.
- Geo. Eastman arranges land swap between Oak Hill Country Club and University of Rochester.
THE
ICE AGE
OTHER
GLACIAL FEATURES IN THE AREA
- KETTLES
KAMES
ESKERS
DRUMLINS
ERRATICS
LAKES
TIMELINES
FOR THE INDIVIDUAL HILLS
- COBB'S HILL
PINNACLE HILL
HIGHLAND PARK
MT HOPE CEMETERY
UNIVERSITY OF ROCHESTER, RIVER CAMPUS
- THE ICE AGE
The Ice Age in North America started approximately two million years ago, and ended about six thousand years ago. Climate fluctuations in the Pleistocene caused several glacial advances and retreats, with the earliest glacier to leave evidence in New York arriving here about 100,000 years ago. The last advance, the Wisconsinan Stage reached it's peak approximately 20,000 years ago, destroying all evidence in New York of previous glacial activity (except for an ice free area in Allegany State Park, which shows some evidence of a previous glacial advance.) The ice mass, called the Laurentide Ice Sheet, named for the Laurentian Mountains where it was centered, spread out to about 2,000 miles in diameter, and 1,000 to 10,000 feet thick. Most of New York State was covered by a protruding portion of this massive ice sheet called the Ontario Lobe. Even though 130,000 km2 of ice covered New York, it amounted to only 1% of the area covered in North America. Sea Level droped 100m to supply all the water used in the Ice Age. This ice would have put about a ton of pressure on each square inch of the ground below. At the end of its 40,000 year stay it had compressed the earth by as much as 2,500 feet! In the 10,000 years since the retreat of the glaciers from Rochester, the land here has risen 250 feet.
Before the ice would finally melt away during the Wisconsin glaciation,
it would advance and recede across Rochester five times. Each time scraping
away old soil and depositing new. The glacial till (well mixed soil left
by the glaciers) in the Genesee Valley is between 200 to 300 feet deep.
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About 12,000 years ago the glacial ice was retreating northward
when it finds new strength and readvances to the south, then stalls. The
stationary ice sheet is heated by the sun creating rivers and streams that
flow through the ice sheet. As this swift moving water rushes along it
picks up debris that has been trapped in the ice. Reaching the edge of
the ice sheet these rivers create a series of outlets that deposit massive
amounts of debris into the waters of Lake Dana. The larger debris
(gravel) accumulates at the base of the ice forming the Pinnacle
Range, the finer sands washing away to the south forming a smooth flat
plain. The base material, under the Pinnacle Range, is a deep layer of
fine sand that had accumulated earlier in the calm waters of Lake Dana.
The range seems to be built up from several centers of accumulation, forming a series of irregular, linear hills extending approximately four miles, forming the eastern portion of the Rochester-Albion moraine. The range is divided into five major sections: Cobb's Hill (560 feet elevation), Pinnacle Hill (749 feet elevation, the tallest, at 240 feet above the plain), the hills of Highland Park )650 feet elevation), Mt. Hope Cemetery (650-670 feet elevation) and the University of Rochester River Campus (Oak Hill was at this site, but it was leveled during the construction of the Oak Hill Country Club. I have not been able to find an elevation for this hill, only that it was very steep. The hill was very popular for sleding in the winter as your ride would end on the frozen river giving extremely long rides.)
Not only is the Pinnacle Range the highest ground in the city, and the highest and most conspicuous location within many miles, but it is the most striking remnant of the Glacial Period. They are described as a 'recessional kame moraine'. This means that the hills were not formed by the furthest advance of the glacier, but by the melt water carrying sand and/or gravel off the ice and depositing it as well sorted deposits. There are also deposits of glacial till spread over top of the area. This means that after the range was formed the glacier advanced once again, covering the area with ice one last time. This glacial appearance must have been a weak effort, because it did not scrape the new hills away, but mearly flowed over top of them. The exit of the ice sheet wasn't a retreat of the ice mass as in the past, but just the melting away of the ice, which droped the well mixed debris trapped in the ice (glacial till) to the ground, creating a 10 - 15 foot cover over some, but not all, of the hills.
The melt water created Lake Dana, a long narrow lake across Central
and Western New York that was trapped between the glacier and the higher
land to the south. As long as the ice sheet blocked the entrance to the
St. Lawrence Valley this water was forced through an outlet at Rome. From
there it flowed down the Mohawk Valley to the ocean which extended up the
flooded the Hudson-Champlain Valley. As the glacier receded northward
it would uncover new outlets, resulting in a rapid draining of the old
lake to a new stable level. This resulted in an entire series of lakes
being formed. Within the city of Rochester there is evidence of the Lake
Iroquois shoreline at 435 feet elevation (This beach is better known as
The Ridge. A geologic feature that was used by Indians as a major east-west
trail, and latter as a stagecoach route. Today Ridge Road, or Route 104,
is the state's longest road.), Lake Dawson shoreline at 480 feet, and Lake
Scottsville at 540 feet.
The excavation of the Range at Brighton has destroyed an interesting
and geologically important feature. The top most deposit was till, a well
mixed material filled with boulders, laid down directly by the ice
itself. It had been deposited on top of the fine sand laid down by
the lake. Here was the clear proof that the ice had backed away to northward
while the lake sands were accumulating, but later it re-advanced and buried
the sand under stony till.
The same glacial history was shown at Cobb's Hill before it was
used for the Reservoir. It had two, well-defined summit ridges of very
stony, boulder rich till.
The Pinnacle also displays evidence of the re-advance of the ice-front.
On the summit of the hill are boulders of our local limestone imbedded
in gravelly till. This shows that while the ice-sheet was over Rochester
its edge pushed up to the summit of the hill.
OTHER GLACIAL FEATURES
IN THE AREA
KETTLES
Kettles are the basins or bowls found only in glacial deposits. Blocks of the ice detached from the glacial mass and were buried in the sand and gravel. They did not melt until long after the glacier was gone. When the ice-block did finally melt the cover slumped in, producing the basin, or kettle.
Some fine examples of kettles have been destroyed in the stretch of the Pinnacle Range lying between South Clinton and South Goodman Streets. One famous feature was the Peat Bog, a very large and deep kettle in the north flank of the Ridge. During the several thousand of years of it's history, it had become filled with vegetable debris, and become peat. Near South Goodman Street, on the east side, was a shallow kettle basin that had filled with water creating a tiny lake, surrounded by graceful elms. The site of these two features is now Highland Parkway.
Fortunately, evidince of the area's glacial past has been preserved in few locations. Mount Hope Cemetery is an area of mounds, eskers, basins, knobs and kettles. Some small, but pretty kettles are in the Dingle (woods), east of Cobb's Hill Reservoir, and a grand display of kettles, some of vast size and depth, are in the Mendon Ponds Park.
KAMES
This term, of Nordic origin, is applied to hills and knolls of glacial sand and gravel. They were built in standing water, usually glacial lakes, by the streams that were draining the ice-sheet. They are really incipient deltas.
The high points of the Pinnacle Range are kames, overridden by the ice, and capped with till. The knolls of Mount Hope Cemetery, and the low rolling hills at the Mendon Ponds Park, are all kames. The hills in Mendon Ponds Park were deposited in Lake Dana at the time when the glacier front stood there, before it receded seven miles to Rochester to create the Pinnacle Range. The elevation of Lake Dana is shown by the smoothed areas on the Mendon kames to be 700 feet. The lake level is yet shown even more clearly by a series of delta remnants in the town of Victor, southwest of the Baker Hill. (Macedon sheet).
ESKERS
It is probable that some small gravel-ridges, with northeast by southwest direction, that would be classified as eskers once existed in the Rochester area. Unfortunately, they would be an ideal source of building material, and so they have probiably been carted away.
Eskers are long, narrow, ridges of gravel, that wind snakelike, in an irregular path across the ground. A puzzle to early investigators, they are easily explained as a glacial deposit. They are the debris left in the in the channels of streams that flowed beneath the ice-sheet.
There are many excellent examples in the area: between Henrietta
Station and Rochester Junction, in the Mendon kame-area are two very large
eskers, and another southeast of Pittsford. A large esker winds through
Mt Hope Cemetery, with Indian Trail Avenue following along it's crest.
DRUMLINS
In the vicinity of Rochester and extending east to Syracuse
is the finest display of drumlins in the world. East of Fairport to Syracuse,
every hill is a drumlin of typical form, and there are thousands.
Drumlins are exceptional features, there are vast areas of the
glaciated territory that have none. The name is Celtic, meaning a little
ridge. Drumlins occur when glaciers re-advance and override a previously
deposited moraine. They are elongated in the direction of ice movement.
There was one example of a drumlin on the east edge of the city
of Rochester. The north end of this drumlin lay on Winton Road one-quater
of a mile south of Clifford Street. It is clearly outlined on topographic
maps. It was one-half mile long, pointing southwest. Lying in the old Ely
farm it has been called the 'Ely drumlin'. In creating the Laurelton Tract,
the crest of this drumlin was cut away to make the grade for Hurstbourne
Road. The excavation revealed that the hill contained several large boulders.
The largest was taken to the University of Rochester, River Campus, as
a monument to Thomas Thackeray Swinburne. These great blocks were all erratics,
crystalline rocks from the Adirondacks or eastern Canada, that had been
rounded by abrasion while being dragged beneath the heavy ice-sheet during
their 150 mile journey south.
ERRATICS
These are the real stone monuments of the Glacial Period. Erratics
were another mystery to early investigators. Boulders were found hundreds
of miles from locations where the rock type occured. These rocks, sometime
immense, could not have been to the high ground where some of them were
found. Others, were left is such awkward positions that they became very
famous as 'perched boulders', or 'ballancing rocks'.
There are none documented in the Rochester area. The wealth of
large boulders revealed in excavations, like that in the Ely drumlin, or
along the Pinnacle range, may not properly be called erratics, as they
were underground.
Lakes
These lakes were formed by the retreating ice mass. New outlets
are exposed resulting in sudden drops in water levels, creating this sucession
of lakes.
Lake Warren ~900' - Erie, Huron, & NY- outlet W across Michigan to Lake Chicago to Mississippi - Ice recedes opens Marcellus outlet,causing drainage to Mohawk - Mendon Ponds deposits, ice front S of Fairport & Pittsford
Lake Dana ~700 - 720' - longest duration - ends with Syracuse outlet
Lake Scottsville ~600 - 500'- controled by Victor outlet
Lake Dawson & Lake Iroquois ~215' > Lake Erie & Niagara Falls formed - outlets at Fairport, Macedon, Palmyra & Lyons - short lived
Lake Iroquois merged from Lake Dawson + Lake Iroquois)
Admiralty Lake ~ 50' > Formed after ice clears the Thousand Island Outlet.
Lake Ontario
TIMELINES FOR THE INDIVIDUAL HILLS
HIGHLAND PARK
1888
UNIVERSITY OF ROCHESTER, RIVER CAMPUS
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