348 
The American Geologist. 
June, 1800 
ly clear manner the increasing depth at which the Cincinnati 
rocks are found and the gradual diminution they undergo in 
thickness toward the west. From a thickness of 900 feet at 
Richmond, they are only 403 feet at Danville, 96 miles distant ; 
and from a hight above the sea level of 964 feet, the top of the 
series descends to 95 feet below sea level. The greatest fall in 
the altitude of the top of the series is between Indianapolis and 
Plainfield, where in a distance of 14 miles, there is a differ- 
ence in elevation of 362 feet; while between this and 
Danville, only four miles west, there is a fall of 112 feet. A 
well at Terre Haute, some fifty nxiles west of Danville, 
was carried to a depth of 2,000 feet and stopped in the 
Corniferous limestone. With the same dip as that between 
Plainfield and Danville,the top of the Cincinnati group would be 
1512 feet below the sea level ; but if the thickness decreased at 
the same rate as between Danville and Plainfield, it must have 
disappeared long before Terre Haute was reached. 
Another intefesting feature between the two places, Danville 
and Plainfield, is shown by Leverett's table. This is the won- 
derful difference in thickness of the Devonian at the two 
places. At Danville this formation is 570 feet thick, but it 
thins out to the eastward, so that at Plainfield, only four miles 
away, it is but 253 feet thick. So that while the Cincinnati 
group thins out toward the west, the Devonian l3dng above, 
diminishes toward the easA. 
be 
(U 
•_2 
^ 
a 
(S 
03 
^ 
a 
a 
M 
„■ 
03 
O'O 
o 
Af 
.;^ +- 
a 
Name of Station. 
ii 
.« o 
o 
OS 
tX 
M 
1)—' 
It 
S 2 
3 ^ 
P o 
5o 
o 
< 
< 
H 
Richmond 

feet 
feet 
feet 
964 
964 
900 
Daleville 
43 
fi3 
63 
70 
825 
850 
829 
794 
545 
490 
469 
403 
505 
305 
305 
510 
Alexandria 
No. 2 
Elwood 
No. 2 
70 
82 
88 
750 
778 
790 
433 
478 
390 
484 
600 
485 
Windfall 
Sharpsvillo 
Fairfield 
93 
98 
121 
130 
803 
815 
614 
61 r 
418 
415 
94 
45 
500 
498 
306 
360 
Flora 
Delphi 
No. 2 
13C 
14-^ 
550 
470 
5B. T. 
35B.T. 
313 
300 
Estimated. 
Monticello 
