Savannah morning news. [volume] (Savannah) 1868-1887, 1886-09-08

quakes In general, and OF the Cnarlestoh
earthquake in particular. That ls, tnese
observations appear TO prove Deyonu
question that the Charleston earthquake
is comparatively local phenomenon,
and in no way connected with the disturb
ances of the earl IS crust, in distant parts
OF the glube. Thus. too, these 00serNa-
tlons appear to prove that the present
earthquake is in no way connected with
vOlcanlsm-that is, that the earthquake
does not afford any ground whatsoever lot
fears OF volcanic action or the eXtruslon
OF layas anywhere within the Atlantic
slope. Moreover, while the observations
themselves are insufficient for the formu-
latlon OF a definite hypothesis as TO
the origin of the earthquake, they 90
unquestionablv indicate that the disturb
ance may be explained on purely physical
grounds. At the same time the geological
structure of the area within which
Charleston is situated and the movement
known to have taken place in the terres-
trial crust in adjacent regions suggest
possible explanation of the disturbance
THAT'S what biologists call good work.
ing hypothesis as to its origin.
In general terms the Atlantic slope is
devisible iuto three distinct regions,
namely: The Appalachian region, eX-
tending from Northeastern Alabama
through Northwestern Georgia, Western
North Carolina, East Tennessee and up to
Pennsylvania. second, the Piedmont
region lying east of the Appalachian
Mountain system and extending from It's
base to sinuous line passing through
Macon, Augusta, Columbia, Weldon,
Richmond, and Washington, within
which region the rocks are
GRANTEES and other crystallizing rocks.
Third, the coastal plane extending from
tho line just mentioned to the shore
OF the Atlantic. Within this region there
are no large masses OF solid rock, the en-
tire plain and its sub.strata consisting Of
marls, Clay aud sands sedom so firmly
lithlHed as.to even form building
these mari, sands, etc., reach an enOr-
nous thickness. AT Charleston the arte-
sian wells do not penetrate them. proba-
bly, do not extend within some hundred
feet of their bases. They are thus proba-
bly, one-half or three-quarters of mile
thick.
Now these unconsolidated deposits of
the coastal plane are rest on the sea-
wardly sloping surface of the GRANTEES
and schists of the Piedmont area. The
entire mass is, therefore, in an unstable
condition, just as heap Of sand or mass
of snow on sloping roof would do, so as
to slide towards the Atlantic. This ten
dency is opposed by the friction OF the
particles OF the mass itself and between
the particles OF The subjacent GRANTEES.
Now the co-efficients Of the fric-
tion, ETC., have not been deter
mined with sufficient accuracy
to enable the biologists to say whether
or not this seward tendency OF the mass
is sufficient to overcome the friction and
thus produce a movement. But here,
fortunately, observation in another part
of the same area comes in. 1t had been
found that in the northern part of the At
lantic slope, that Is the part between the
south line of Virginia and New York, an
other coastal plane area, in which the
geological structure is identical with that
of Charleston, has suffered displacement
in recent geological times. and the dis
placement was OF just such character as
to indicate that this position Of the mass
has slipped seaw ard-that is that the en-
tire area has been affected by gigantic
landslip. OF course any conservative ge-
olOgist feels much hesitation in extending
an hypothesis which appears to meet the
requirements of the case in the northern
pant of the Atlantic slope to the southern,
and accordingly this hypothesis is only
enunciated as possible one which may
| be ultimately oyerthroWn when the full
| harvest of facts has been garnered.
| 1t can scarcely be said that the Observa-
| tiOns so far made sustain the hypo-
thesis, although they do not oppose it.
| But, in connection with this, or any other
| tenable hypothesis as to the origin Of the
| Charleston earthquake, they decidedly in
| dictate that the climax is now past and
| that all OF the shocks which have &C.
CURED, both here and at Summerville,
since last Tuesday evening represent a
series of progressively diminishing vio-
| lence, and indicate, too, that this series
will terminate at an early date.