Mark now the geology of the ravine. For about half way from where
it opens to the shore, to where the path is obstructed by the deep
mossy pool and the cascade, its precipitous sides consist of three
bars or stories. There is first, reckoning from the stream upwards,
a broad bar of pale red; then a broad bar of pale lead color; last
and highest, a broad bar of pale yellow; and above all, there rises
a steep green slope, that continues its ascent till it gains the top
of the ridge. The middle, lead-colored bar is an ichthyolite bed, a
place of sepulture among the rocks, where the dead lie by myriads.
The yellow bar above is a thick bed of saliferous sandstone. We
may see the projections on which the sun has beat most powerfully
covered with a white crust of salt; and it may be deemed worthy of
remark, in connection with the circumstance, that its shelves and
crannies are richer in vegetation than those of the other bars. The
pale red bar below is composed of a coarser and harder sandstone,
which forms an upper moiety of the arenaceous portion of the great
conglomerate. Now mark, further, that on reaching a midway point
between the beach and the cascade, this triple-barred line of
precipices abruptly terminates, and a line of precipices of coarse
conglomerate as abruptly begins. I occasionally pass a continuous
wall, built at two different periods, and composed of two different
kinds of materials: the one half of it is formed of white sandstone,
the other half of a dark-colored basalt; and the place where the
sandstone ends and the basalt begins is marked by a vertical line, on
the one side of which all is dark colored, while all is of a light
color on the other. Equally marked and abrupt is the vertical line
which separates the triple-barred from the conglomerate cliffs of
the ravine of Eathie. The ravine itself may be described as a fault
in the strata; but here is a fault, lying at right angles with it,
on a much larger scale: the great conglomerate on which the triple
bars rest has been cast up at least two hundred feet, and placed
side by side with them. And yet the surface above bears no trace of
the catastrophe. Denuding agencies of even greater power than those
which have hollowed out the cliffs of the neighboring coast, or whose
operations have been prolonged through periods of even more extended
duration, have ground down the projected line of the upheaved mass
to the level of the undisturbed masses beside it. Now, mark further,
as we ascend the ravine, that the grand cause of the disturbance
appears to illustrate, as it were, and that very happily, the manner
in which the fault was originally produced. The precipice, over which
the stream leaps at one bound into the mossy hollow, is composed of
granitic gneiss, and seems evidently to have intruded itself, with
much disturbance, among the surrounding conglomerate and sandstones.
A few hundred yards higher up the dell, there is another much loftier
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