The Lambertville record. [volume] (Lambertville, N.J.) 1872-1968, 1874-07-22

Trap dixie. Hence we see that the BRsaltic
dyke above described has the same dip as the
neighboring red-shale. Had the red-shale
been rent vertically the dyke would stand ver-
tically, and the shale could not comfortably
overlie it. But this condition is seen in many
places. Again, this redshale is naturally a
soft rock, easily broken, and when exposed to
the air soon shows tendency to divide up in
to laminae or thin layers, and in short time
crumbles to fine soil capable of producing
without the admixture of any fertilizer, an
exuberant growth of vegetation But as this
mass of molten rock 200 feet thick was inject
ed between layers of red-shale, their contigu-
.ous parts became indurated--balxed hard like
the potter's clay in making stone ware, and
was converted from the soft and easily frac-
tured Triassic rock into very hard flinty
"altered shale," which when struck with a
hammer rings like pot-metal, specimens of
which may be picked up almost anywhere
along the brow of the mountain.
As the intensity of heat was greatest near
est the molten dyke, so the layers nearest this
mass were baked the hardest, and in proper
ton as they were farther removed therefrom,
in that proportion they show less and less in
fiuence of heat, until at length they exhibit
their normal appearance. It is evident that
the injection of a dyke in the manner above
described would produce an elevation about
equal to the thickness of the injected matter,
and this would form the outline of ridge, OF
mountain, or at least would act as water
shed in directing the course of the streams of
this region.
But we must not commit the error of esti-
mating the thickness of the dyke by the
height of the mountain, for other agencies
hereafter to be considered had much to do
with giving it its present shape and impor-
lance.
The soil made by the disintegration of this
"altered shale y or fire-rock is clayey, and
in many places are found beds of clay suited
to making earthenware, brick, tile, and the
like, some of which are now extensively work
ed. But for agricultural purposes it is much
inferior to the soil formed by the Wondering
of the Basaltic powders. The springs here
in found are seldom constant and generally
have blush appearance depending upon a
quantity of Argyll held in solution. This
clayey soil is the least desirable of the noun
tain land.
From Dlts' Peak n. L. extends a ridge
known as the Rattlesnake, much inferior in
elevation and breadth, but of sufficient geo.
graphical Importance to demand, at least,
passing notice. This ridge, quite uniform in
it's altitude, which averages about 140 it, above
the bed of the Back Brook south bra,aai. az
tho NesIeaio, narrow upon the top, sloping
with almost equal sides to the n. w. and S.
East crossed near its centre through deep
ravine by the Mountain Brook, displays only
upon the western extremity for about a mile
any Trappean powders, nor is the Trap seen
in place any where throughout its course
But should we make up our minds regarding
its composition from tho appearance of the
indurate Red-shale, we would judge that a
thin seam or dyke of Trap might yet, by a
little excavating, be brought to view.
The peculiar metallic ring and finty appear
ance of the altered shale y found in many
places along its crest leads It's to believe that
it has been subject to the influence of heat
more intense than that of the formation gen.
orally. The effect of this ridge, the crest of
which runs almost parallel to the brow of the
Sourland range at a distance Of about 2 miles,
is most favorable to the fertility of the dis
trict and to the beauty of its scenery. Its
gentle slope toward the SOUTHEAST meeting
the Sourland's equally gentle slope towards
the N. W., tastefully divided into well-tilled
farms, richly bespangled with farm houses and
out-buildings, with well-fenced fields and me-
andering streams, when viewed from an en-
inence at the western terminus of the long
and graceful valley, affords scenery, for this
region, rare and charming. As the range of
our vision is directed along its course, farm
house after farmhouse meets our view in
such rapid and yet such pleasant succession
that we can hardly persuade ourselves but
that in the distance is a most beautiful vii
lage.
From Stockton, upon the Delaware, N. E.
extends a ridge almost dividing this valley.
This same ridge may be traced from Fish
er's peak across the Alexsauken south Of Mt.
Airy, across the York road, at the summit
near Isaac Matthew's, at an altitude Of 210 #.
above the level of the sea, across the farms of
VIM. Holcombe, I. Matthews, S. B. Hudnit
and Andrew B. Holcombe to the Delaware
river.
Along the crest at some places We picked
up fragments of Trap, especially upon the farm
of l. Matthews, where they were SO numerous
as to give the peculiar appearance to the soil
In the gorge of a hill to the east of A B. Hol-
combe's house the Trap is seen in place. The
layer is very thin and consequently it resem-
bles that which we frequently see lying be-
tween the Altered Shale aud the coarse Ba-
saltic Trap in many exposures and which we
might with some degree of propriety call
Transition Trap, from the circumstance that
it is the connecting link between the coarse
Trap and the Altered Shales
In order that the several grades of Ba-
saltic Trap may be the better understood, al
low me just here to say few words by way
of explanation. Doubtless, all the trap of
this region has flowed out from one great
fountain, the molten mass of the centre Of the