The weekly Floridian. [volume] (Tallahassee, Fla.) 1867-19??, 1881-02-01

PINE CASTLE, ORANGE COUNTY, Jan. 10, '81.
Editor F1osIdian AT q lecture delivered in
Orlando on the Goth ult., to body of some Of
the most intelligent gentlemen Of Orange county,
set forth some personal observations which led
one 10 the conclusion that South Florida, like
the analogous peninsulas of Scandinavia and
Greenland, was slowly, but sensibly sinking. /
suggested the absolute need of scientific observa-
ton to determine these facts. A request was
made that should put the lecture in pamphlet
form. My engagements at present do not admit
of my undertaking this, even 30 far as to write
out the notes of the lecture but the time is 80
opportune, the advantage to every department
of the State 80 apparent, and much more of the
people at large for such investig alton by an or
ganized corps of geologists and engi neers, am
glad to set forth briefly the matter.
In the physical history of the globe it is known
that its qualification consists of underlying plu.
tonic Ggneous, melted by fire) rocks, upon
which in regular order of qualification, joints and
clearage, however disturbed by dip and strike,
are found sandstones or conglomerate clays and
sicates overlaid by lime stones, dolomite (carb.
of limeO or mountain lime stone, followed by
are usually cntercalaied with carboniferous, ex-
pressed either in anthracite and bituminous coal,
or brown coal, Ignite, peat, or the peculiar
humus known in Orange county as muck. 1t is
characteristic Of the coal-bearing strata that it
exhibits frequent alterations, the coal lying be-
tween clay beds or schisls containing stigmarid,
or the roots Of such fossil plants as constitute
coal by heat aud pressue. The constituents OF
the soil oil South Florida and especially its vege-
tation of ferns, equisite genus of plants resem
bling horses iails) club MOSES, &c, are charac-
teristic of the coal measures and, priori we
must anticipate the variation Of surface caused
by gradual accumulation of matter over an
inchoate and not densely packed sand.
This probability is strengthened by an evident
geologic difference between East and West Flor
ida. The chalks Of South Georgia everything
the palaozoic (rocks containing animal fossils)
rocks which crop out on the west side, are over
laid on the east by coral reef and the accumula-
tons OF silt AMI sand fllisg up gradually the
sounds. The process is exhibited not only by
Indian river and the ST. Johns, exhibiting peri
DDS in the growth OF the soil or land; but also
by the Ocklawaka, and the chains OF lakes char
acteristic Of South Florida. The sand hills or
dunes in the west Of Orange define the ancient
coast, and the gypseous (relating 10 GYPSUM rock
Characteristic OF the INTERROGATION of the chalk
and clay beds Is shown In the various sulphur
springs breaking out In . north and south trend
through the peninsula. A soil 90 characterized,
is necessarily loose, and the accumulations nee
essarily press down the underlying sands and
coral rag
The sinking Is therefore a mechanical cense-
quence of the relation Of forces on the soil The
question arising is 10 know If this superficial
growth exceeds or corresponds with the depres
sion.
On this point. my own observations and inves-
LEGATIONS contradict an inference of equilibrium.
l hDd that the low water mark In Lake
Conway b from inches to foot higher than
ten years ago. Mr., Robertson, County Surveyor,
assures me that oil trees marked on government
surveys. a. on lake margin, arc now well out
in the water. Mr. Mott. engineer, In digging
drain from Lake Conway to Marah Prairie, re-
ported TO me that he found charred sticks four
ieet below the surface disposed 10 for an Indian
hre. Dr.. Kilmer tells me, that digging well In
Orange county, flint knife was found sixty feet
below the surface. These lActs not only indicate
. quiet, gradual depression, but an advance Of
the water lsvel. This may be- local. Portions
may Be sinking IN the interior bat rising On The
coast OF the lakes may be hlling OF their BEDS
rising. casing an Overflow.
When W consider the various schsmes Of
draining and rsclsiming laks beds and over
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