12 W. B. Dwight on a Subsidence of Land. 
Art. ITI.—On a Subsidence of land at Coxsackie, N. Y.; by Rev. 
W. B. Dwicur. 
An occurrence of this kind hae come long my obse 
tion in 1863, (and in a subsequent visit 4 the locality in 1864,) 
which is of remarkable extent, and which combines, besides 
many other interesting features, the double effect of depression 
and of elevation, I think it desirable to put an account of it 
upon record. 
the loc locality is upon the farm of Mr. Casper ecg four 
miles north of the village of ig pee N. Y., and two miles 
west of the Hudson river.’ ost-tertiary terrace ot ae a 
width of about three miles, on its extreme western limit at 
the base of a bold ridge of Helderberg limestones, from which 
line its surface continues quite level and unbroken toward the 
oth till, at the distance of one mile from the hills, it reaches the 
e which is the scene of this movement. Here a creek has 
a a ravine or valley of a considerable size, cutting 
through the terrace, which stands at the same level on both sides 
of the valley. The banks thus formed are by no means steep, 
but gradual ‘declivities ; the terrace ae ed was © atens 75 feet above 
the bed of the ereek previous us to the disturbance. bia general 
course of the creek and valley at this point is N. 45° E; buta 
little below, and just at the termination of the slide. the course 
is north; the stream was eight feet wide, and six feet deep. 
the terrace consists superficially of light-colored clay soil, 
mixed with sand and stones. Underneath this there is a thick 
stratum of ot gray ao quite oe consolidated into well- 
defined horizontal laminze of roc k, very soft and porous, very 
f ~ and free fom grit, but containing a sete amount of 
lime. These solidated lamin do n t appear except where 
tk here has i ‘ recent excavation, as exposure soon destr roys 
their structure; about fifty feet of these layers could be made out 
not able toascertain. Below these light-colored layers is a de- 
: - of blue clay, everywhere quite distinct from the other, as 
stated by the New York State Reports: “these clays are almost 
formly aimee the blue lying below the other; es line 
th pleasure, my indebtedness to Mr. 
ee ee 
at the fracture of the slide; how much greater their depth, ] was 
et ee ac a rit er Simin: r. Casper Fla th, the 
__ @wner of the property upon which t ence took lace, for dial asciat 
foe cd ale a Whitbeck o {Coxsackie fo ani nate sone 
