Evening star., 1898-03-04
UNDERGROUND STREAMS.
Thousands of Miles of Subterranean
Rivers in Kentucky.

Rivers in Kentucky.
Mr.. John r. Proctor. formerly state geol-
| ogist of Kentucky. has written an article
! for the March Century on The Mammoth
| Cave of Kentucky" Mr.. Proctor says:
Passing southwark through Kentucky on
| the Louisville and Nashville railway, the
| observant trave.er will notice that about
| forty miles from Louisville the road climbs
Muldrows Hill. which is the northern es-
| carp1nent OF an elevated limestone plateau
sloping gently to the south and west. The
road traverses this plateau for about one
| hundred miles and descends southern
escarpment into the basin Of central Ten
nessee. In this distance only three streams
are crossed-Nolin, Green and Barren
| rivers; and between these rivers the entire
surface drainage passes away through sab
terranean channels, giving rise to a curious
''sink-hole" topography which is peculiar to
this region. These circular and ovai-shaped
depressions are so numerous that in places
the rims almost touch one another and one
can sometimes count several hundred to the
square mile. Through vents at the bottom
of these sinks the surface water passes
downward into caverns and underground
streams emptying into the above-named
rivers through arched ways near water
level, and in places beneath the surface of
the rivers.
The surface rock Of this plateau is the
| subcarbonferous limestone. which is here
several hundred feet thick, massive,
markably homogeneous rock, with no inter-
Vening strata of shale or sandstone-condi-
tions most favorable for the formation of
caverns; consequently this region contains
more and larger caves in given area than
any other region in the world. In Edmon-
son county, where the celebrated Mammoth
Cave Is located, 1t is claimed that there are
as many as five hundred known caverns
A range Of hills of uniform height run
ming parallel with the railway and several
a n UyiIl he nhHar
On nearer inspection this will be seen to be
level plateau rising out of the limestone
plain, and held up by Gaping of massive
sandstone. 1t Is beneath the protection of
this sandstone-capped plateau that the
larger caves are found. Green river has cut
through this plateau to depth of about
30 feet: and as the sandstone cap is about
seventy feet thick, We find about 80 feet
OF massive limestone exposed above the
dra inage-level AS some of the domes and
upper avenues of the caves extend up to
the base Of the sandstone, and some down
to the drainage-level. we thus have go
feet as the present limit of the vertical
extension Of these caves. The evidence is
conclusive that these caves have bsen cut
down to correspond with the deepening of
the channel cut by Green river. In the
region imm ediately along the line of the
railway. where the sandstone capping and
the upper limestone have been removed by
erosion, the caverns have less vertical ex-
ter sion. and correspond to the lower ave-
IttcS u the anu OIneF caves 10
the north, Doubtless large caverns, cor
responding to those now remaining beneath
the sandstone plateau. existed here before
the upper member Of the limestone was
Ell ode from this area.
There is no means of estimating the ex-
tent of the caNerns and subterranean
streams in this region. Every one Of the
iEnumerable depressions or sink holes
save where the vents have been closed,
thus forming ponds - communicates with
! an underground channel or cave, and the
aggregate length of such channels has
been estimated at many thousands OF miles.
Nor can we form any estimate Of the num-
Der and extent Of large caverns yet undis-
covered. But for the erosion caused by a
small stream cutting through the roof OF
Mammoth Cave the present entrance would
not have been broken open, and this, the
known. Several other of the largest and
mCst b6 autiful caves in this region have
been found by accident. Hidden grandeurs
doubtless yet remain entombed beneath the
extensive uplandS reaching out on both
sides of Green river.
In crossing the southern upland we come
upon oval-shaped limestone valleys, sur
rounded on all sides by a sandstone rim,
with no outlet save through vents in the
bottom. These valleys are sometimes hun
dreds Of acres in extent, and are probably
formed by the falling in Of extensive cav
erns, the debris, disintegrated by the ele-
ments, being carried away through the
subterranean channels. The fact that ex-
listing caves under the hills surrounding
these valleys have been found through en-
frances in the sides of some of the valleys
Is an indication that this may have been
the condition.