New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1891-11-05
GEOLOGY OF GRAND FALLS
THE CIIAsM THIRTY MILES LONG wHICB
The WATERS HAVE EXCAvATED.
CHARACTER OF THE GNEIss ROCK THROUGH
WHICH THE RIVER MADE ITS wAY-cEx.
TRIAL LABRADOR NOT A TABLE
LAND BUT REGION OF NOUN:
TAINS AND LAKES.

TAIys AND LAKES.
st. Johns, n. F., Oct. I6.-The Grand River @
Labrador, which the now famous falls has IL
origin in Lake PetchapOu in the very heart OF tids
vast peninsula. From this great lake chain q
smaller lakes, with their connecting rivers. stretches
| northward toward Fort Chimmo. Ungava Bay
Lake Pctchkapou receives the overflow Of these lakes
Tho of Grand River from this lake is directly
south till tho Grand Fails reached. From that
point 1t takes first a southeast and at Horse-
shoe Rapids 1t turns northeast and fails into Melville
Bay ut the head Of Hamilton Inlet Its entire course
Is estimated at 400 miles. At its mouth II Is mile
and quarter in width, and 1t receives numerous
afiuents In its course.
The falls proper were found by Messrs Bryant enc
Kenaston to be 31G feet IN height After precipatn&
itself the rock into the abyss below the river
pursues its maddened course through a narrow
ravne or canon, having rocky walls from 300 TO 400
In height, and extending from twenty five thirty
miles. The course Of the river through this IL
zgzag, presenting sharp angles at intervals After
emerging from this huge cilasn 1t pursues auictcs
course broken, however By numerous rapids.
The question at once presents ITSELF has the rver
during myrads Of ages slowly eaten It's way backward
through the rocks for a distance OF thirty miles
Only a competent geoogst after careful examina-
uon, could answer this question satisfactorily. Bus
there many circumstances which forcibly suggest
the strong probability that the river has excavatcd
this immense chasm through which 1t flows. and that
tie falls are constantly receding. The Of
the gorge through IS entire the perpendicular
character Of the cliffs that overhang the river which
seem In places to be undermined on one side by the
force OF tho current appear to point to the conclusion
that the erosive action Of the falling such great
height has away the solid rock aud that the faIls
have receded this great distance.
The vast periods Of time required 10 produce such
result might lead to reject such hypothesis. Let
remembered. hat hav
orally arrived at the conclusion that the Falls Of
Niagara were once at Queenstown Heights, and that
the river has cut its way backward miles TO the
present site Of the cataract. From certain data the
eminent geologis Sir Charles Lyeil estimated that 10
would have required $1,000 years for the retreat Of
the falls from the escarpment at Queenstown to theis
present position. The uppermost rock is hard
Siluran limestone ninety feet thick but beneath 10
soft shacs which undermined BY the spray and
constantly crumbe away, that the incumbent rock
falls down in great masses. suppose similar per.
petual and progressive waste to have been going
for enormous periods Of time at the Grand Falls Of
Labrador and there is nothing inconceivable In such
an excavation having taken place. Time is nothing
in natures mighty processes. "A thousand years are
day."
OF course much depends on the character Of the
rock through which the erosve action has taken place.
Mr.. Bryant has kindly given me small fragment
Of the rock taken from the edge OF the falls. find,
abundant Of the archaean rocks These ancient rocks
are regarded By biologists part OF the prlmeval
crust the planet, deposited chemical precpitates
mechanical sediments the floor Of the primcval
and since more or less crystallzed and dis
turbed. The archaean rocks occupy AREA Of mora
than 100000 square miles in the northerly part Of
North America, stretching from tho Arctic regions
southwark to the great lakes "Gleiss,' says Lyen.
may be called strati1ed foliated granite, being
formed of the materials granite namely field
SPAR quartz and mica. The white layers consist
almost entirely of granular feldspar, with here
aud there spech OF mica and grain OK
quartz The dark layers composed OF gray
| quartz and black mica, with occasionally grain
of fcdspar intemlxed. Tho rock splits most easily In
the plane these darker layers, and the surface thus
exposed is almost entirely covered with shining spange
of mica. The accompanying quartz, however, greatly
prcdomnates In quantity, but the most ready cleavage
! is determined by the abundance Of mica in certain
parts OF the dark layer. Instead of consisting Of
these thin laminae, gneiss Is sometimes simply divided
| into thick BEDS in which the mica has only slight
degree Of parallesm - the planes of stratiacaton.'
IL appears from the foregoing dsfnton that gneiss
is stratiaed and foiated rock, often having thin
! laninae; and is not hard isneous rock. 1 observe
in the specimen l possess abundance OF mica, so
that cleavage Is difficult. In fact such a amna-
ted or foated rock readily disntegates and crumbles
away under such force OF falling water US tlat at
Grand Falls 1 readily scrape particles from this
render it possible. There is nothing inconceivabis In
the hypothesis that me river has scoopd out deep
channel through this geissic rock, twenty-five or
thirty miles Ia length and 700 20 400 feet in depth.
during the aecns Of past time
should this supp0siuon be verified by geological
examination of region and the canon Itself, then
We have in this lonely wilderness one OF the most
extraordinary of natures operations. The numerous
angles sharp winding, Of ille gorge may possibly
mark the various stages through which the falls have
passed, rs they cutting their way backwasl
Here is a paradise for geologists a study Of thus
wonderful chasm and OF this vast primitive region VIII
add another Interesting chapter To the story 81 our
earth. We have heard much about the great table,
land 900 feet above tho level when Is said 10
occupy the interior of Labrador Professor kenaston
has grave doubts whether any such tableland exists
| lie assembled an eminence some distance above the
falls where he had extensive view of the surround.
| ing country. lie only rolling mountainous
eypanse which was evidently the height OF land or
watershed bur no appearance of table land Rolling
| hills with numerous lakes met the eye cv~ywhere.
II is possble the Labrador taDcland will prove ~ be
| a MYTH As far / am aware, Professor Hind, who
accented the Molsic River from the Gulf side Of Labra
DOR is the only writer who mentions this tabe.land
and he had no opportunity OF observing 1t. Here IL
field for daring explorers, with numerous geographi
cal problems TO be solved, and much to be learned
about natures productions in this grim archaean