26 
nuation of the bafe of many primitive 
mountains in Calabria, there are found 
fucceflive ftrata, compofed of quartzy 
fand, pebbles, white argill, grains of feld- 
fpath, and mica, as if formed by depofi- 
tion. Thete ftrata, which have originated 
from the decompofition of grauite, and 
are intermixed with fhells, and fragments 
of marine bodies, appear to have been 
depofited by the fea. -Phefe depofittuns, 
at firft horizontal fiom north to fouth, 
and with an inclmation trom eatl to wett, 
have afterwards been jeparated, either 
by the currents of the fea itfelt, or by fu- 
perior torrents, and have forined that 
ducceflion of hills, valhes, and -plains, 
which terminate ina low fore. On this 
moveable bafis, is a bed of black or red- 
coloured, argillaceous vegetable earth, 
trom two to five feet in thickneis, ex- 
tremely compact and tenacious, forming 
w kind of cruft which contributes to give, 
a fmall decree of folidity to the foil. It 
has been ho!llewed out by copious rains, 
into deep furrows, and gorges, which are 
fometimes fix hundred feet in depth. 
Their banks are precipitous, and almoft. 
vertical like walls, becaufe the fwperior 
firatum, being bound together by roots, - 
retains the fuper-incumbent foil. 
». It refults from a general examination, 
that granite conftitutes the bafe of nearly 
all Calabria; and that under this appar- 
ently immoveable, balis, is fituated the 
focus of the earthquakes to which it is fo 
able. 
Dolomieu, when fpeaking of the 
effects produced by the principal fhock of 
the earthquake which occurred on the 
5th of February, 1783, and only latted 
two minutes, deicribes them in the fol- 
iowing manner: 
‘‘T cannot. better explain thefe effects 
than by fuppoiing that feveral cubes 
formed of iand, moiftened, and heaped 
“up by the hand, are placed upon atable, 
at a little diftance from one another; if 
we tarther fuppofe, that repeated blows 
are given to the table underneath, while 
at the fame time it is fhaken violentiy in 
a horizontal direction, we may then forin 
tome idea of the different motions with 
which the earth was agitated on that oc- 
ecahon. Beiides thefe tranfient fuccnfli- 
-ons, heaving up and down, and a kind of, 
~ whirling motion alfo occurred, fo that it 
was utterly impoihble any edifice could 
srefift their umited influence; houfes and 
‘even whole villages were levelled in the- 
fame inftant, their foundations appeared 
as if they had been ejected by the earth 
Whichicontamed them; and the itones 
Effects of a late Earthquake in Calabria. 
-three or 
pofittiom «~~ 
(Feb. f, 
which compofed them were broken an& 
{hattered in a thoufand pieces. The ge- 
neral etfect produced upon the argilla- 
ceous fandy foil of the plain was, that it 
acquired an augmentation of denfity by 
the diminution of ts bulk, that declivities 
were formed where before precipices 
only exitted, that internal cavities were 
filled up, &e. The confequence was 
that, throughout nearly the whole length 
of the chain, the fork which had been 
fupported by the gramite of the-moun= 
tains Caulone, Efope, Sagra, and Afpra- 
monte, ‘glided down the folid nucleus, 
leaving an opening feveral feetin breadth, 
anel nine or ten miles in length. Thus 
whole frelds have funk below their former 
level, without any of the furrounding 
{pots having experienced a fimilar change, 
and forined in this manner hollow batons. 
Other portions of land have affimed an 
inclined form, while openings and fiflures 
appear interleéting hillocks and plaitfs 
in every direction: " Almoit at every itep 
we met with fuch openings; but it was 
principally towards the borders of ileep 
declivities, that the greateft confuiion 
prevailed, Cuontiderable portions of fou, 
eovered with vines and olive trees, were | 
detached, and thrown down in a fingle 
‘mafs into the hollow of the valires, de- 
{cribing arches of circles, having as radu 
the height of the declivities; in that cafe, 
the upper portions om which ‘the trees 
ftood, were removed to a confiderable 
diftance from their former fituation, and 
‘remained in a vertical pofitron. ' 
{tis proper to remark, that as the foil 
of the plain-did not forma mafsconnetted 
together in its parts, tt was ill caleulated 
to propagate motion, fo that its inferior 
portion received more than it communi- 
cated to the upper furfaces. Hence it is, 
that the lower parts have always fallen 
firit, and glidits away, like fluids, from 
underneath the bodiesfupported by them; 
-thete bodies funk by their own weight. 
“ When the projectile force communi- 
eated was unufually ‘great, the foil was 
frequently carried over little’ hills, and. 
tranfported to a.conlderable diftance be- 
youd them. When the oppofite fides of 
a valley met, they Se a 
kind of vault, or cradle.~ Bat the m 
‘common effect was, when the inferiar— 
-bafe having given way, the fuperior foil 
had fallen perpendicularly, and fuccef- 
fively in large portions fo as to aflume a 
pofition fimilar to the fteps of an amphi- 
theatre. The loweft ftep is fometimes 
four hundred feet below its firit 
6c Tn 
s 
