New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1906-09-30
ATLANTIC COAST SINKING
Engineers on Ne7o Aeueduct Havs
Trouble soith Hudson,s Red

The Atlantic Coast is sinking accors,,1 ,o
James F. Sanoorn' one OF the enrine.rs ., ira
Board OF Water Supply, that has charg. :. ~.
S16l.000yOOO undertaking to supply New york
City with water from the Catskills Mr. San
born estimates that the coast is dropptnr ar f1,s
rate of one foot In one hundred years Conev
Island will eventually be wiped out and IN,
Statue OF Liberty will be submerged.
Many curious geological features are bs,nc
discovered by the engineers surveying for the
proposed aqueduct. The Hudson River Is an
arm OF the sea TO Albany, they say. a drowned
river" as one called it.
The sea floor. too. is sinking" saws Mr. San
born IN a report issued yesterday CHOSE who
keep watch Of the tide gauges from Boston TO
Key West have proved this TO their satisfac-
ton"
Mr. Sanborn went 10 say that Manhattan
was Formerly mountain top as high as any
Catslill peak now. Soundings have been made
which show that the Hudson River channel did
not end at the Narrows, but extended as a sub
merged gorge fully thirty miles from land This
gorge reached the depth of 5000 feet, cash in
the floor of the sea. Biologists say this deep
place was once a stream bed on the earth's sur
face and has been drowned by the sea and as
the earth progressed sank.
Mr.. Sanborn told how soundings made for a
tunnel planned 10 cross under the Hudson at
New Hamburg revealed 10 the engineers that
The sinking Of the country has submerged the old
rock floor Of the river $50 feet below tide level
Near West Point the bed rock is at least 800
feet down. The engineers first thought they
would lay steel pipes on the bed of the river TO
conduct the water from the projected reservoir
at Ashokan, but a tunnel fifteen feet in
diameter will be bored 400 feet below the sur
face OF the river. AS the water in the reservoir
west Of the river will be 400 feet above river
level it viii have to drop down shaft 800 feet
deep to reach the tunnel.
An this trouble is due TO the idosyncracies
of the river bed" says Mr.. sanborn. AT New
Hamburg a belt of limestone mile wide. from
east to west, WIS found thrust up through the
natural formation of shale This IS due 10
wrinkle in the earth. The limestone was
squeezed up from underneath a bed OF shale that
time had deposited on il. This is due to an
overthrust fault
The earth's outer shell has been wrinkled up
and the limestone squeezed out over the shale.
There is such an overthrust fault in Scotland
where the rock has been pushed out ten miles
along the top OF the rock beneath.
Another Interesting find was that the gigan-
tic Ashokan reservoir 10 be constructed IN the
Catsklll Mountains was once huge natural
dam itself and icons of ages since there was a
lake that land. This dam a great clay
and bowder hill deposited by the continental
some fifty thousand years ago"
The engineers have found that the Catskill
rocks are usually fiat. They consist of sand
stone beds ana shales made by layers Of mud
and sand soIidiAed by the pressure of mud
stones on top. This is the rock from which flag
stones are made. They lie on top of each other
like leaves of a book.
Mr.. Sanborn says that in the valley Of
Rondout Creek. back Of the Shawangunk Noun
tains and Lake Mohonk, there is wide belt Of
limestone known the Heidelberg series.
Through this belt the aqueduct tunnel will have
20 run for about q mile. passing beneath Rondout
Creek He says:
When the new Croton aqueduct was built
under the Harlem River a lot OF trouble
caused by a faulted seam of decayed limestone
which so narrow that IL escaped the search
of the exploring drills. The engineers have been
very anxious not 10 repeat in this limestone the
experience at the Harlem River when the drill
runners were one day driven out of the heading
by a stream OF water which came through the
hole they were drilling.
II II is decided not to bore thsbprojected tun-
mel at New Hamburg 81 may be built at Little
Stony Point, at Old Crow Nest