Anti-slavery bugle. [volume] (New-Lisbon, Ohio) 1845-1861, 1853-01-29
CeOlOgy.-DefinlllOn Of Terms.

We commend the study Of these terms TO |
every farmers hoy in America; aud even if
some of the boys fathers would earu them,
il would enable them better to understand
matters of the must essential importance to
IN h,m in their occupation.
Rocks are divided iuio two great classes,
viz +: siraiifed aud unsirdiifed.
Hr1iifcdtion consists ut the division of n
rock INTO regular parallel planes or leaves,
varying ia thickness from that OF thin paper,
To several yards. Strata are often tortu0us
and variable in thickness IN different paris
of the same aminu or layer nevertheless,
the Fundamental idea of stralilication, is that
of pnrIcism in the layers" The term
structun is sometimes employed to dcsg-
nate the whole mass of n rock, while its
parallel subdivisions nre called hrda, or lay
urs. So also of saud, clay gravel, Sc.
| The term Bed is used to designate a layer
! or mass OF rock more or less Irregular, leu
ticular or wedge shaped, lying between the
| layers OF another rock-sueh as beds of coal,
gypsum, or iron.
| A Seam is n Thin layer of rock that sepa.
rates tie beds or strata of another rock, us
a seam of coal, limestone, &c.
! A Joint is separation of rocks, both
stratifed and unstratiiicd, into mnsses Oi
some deterininate shape: Joints are more
or less parallel, aud usually cross the beds
Oblqurly.
Ciearage planes nrc divisions in rocks
which do not coincide with those Of strait.
fcation, Illumination or joints. They arc
supposed To result from a crystalline arrange.
mcnt of the particles OF the rock.
IIori=onidL strata are those which have
iitilc or no inclination but lie parallel with
,I..
almost all stnta being more or less inclined
The Dir of strata signifies the angle
which it tnrms with tire horizon.
Oicrop. WHEN tie strata are uncovered
above the surface, or protrudG from the side
of hill SO Us to be visible, they are said It
crop oui.
An Escqpement is formed when strata ter
inmate abruptly, so us to form precipice.
A Fault IN rock is the dislocatiou o
strata, so that their continuity is destroyed
and series OF strata on one or both sidrl
: of the fracture arc forced from their Originn
position, aud raised one above another, o.
moved literally. Faults are generally iillei
with clay, sand aud fragments OF o,Le
J rocks.
! A Gorge is wide and open. fissure o
: fault; when still wider, with sloping side
aud rounded ut the bottom, it is called
) valley.
A Dyke is a mass or wall of rocl; inter
POSED between the ends OF disl0caIion, -
as TO break their cOntiuuIy-dyke kes rurcl.
send off branches.
PeinS are portions of rock smaller thai
dykes, proceeding from some large mass
; aud ramitying through rock of diileren
kind. Metallic veins were originally melt
ed metals, which were injected iulo the fs
slires and crevces Of rocks by some subter
ranea1i force.
foSSi.-This term includes those petrife
/ remnins of plants aud animals which mr.
! found IN allnviunI, or ilnheded in solid rock
; and constituting lis structure.
: Formations. The term formation is use
. To designate group of rocks Imving som
character in ntnou---eilher in relation |
G nge, origin or composition. Every form;
If ton consists OF several varieties of rock, u
II agreeing in certain qualities, aud occupyiu
: such relative situations as TO Indicate tli
K they were formed during the same pcrio
It and under the same circumstances. tn,
It we speak OF gray wackc formation, gnei
Y formation, coal formation, &c.