BERKEY, GEOLOGY OF SOUTHERN MANHATTAN ISLAND 265 
Bridge No. 3, “Manhattan Bridge” 
The cores obtained from the borings made at the site of this bridge are 
housed together with those from Blackwell’s Island Bridge (No. 4) at the 
Brooklyn terminal of Bridge No. 1 (old Brooklyn Bridge). The location 
of the different borings is not in every case clear. Nos. 3, 5 and 6 are 
certainly correctly located. The others are less certain. 
The datum M. L. W. is 2.43' below mean sea level (U. S. datum), M. H. 
W. is +4.15'. 
a) Brooklyn Pier. 
Serial No. 
Original 
mark 
Location 
Depth 
to rock 
M. L. W. 
To Rock 
U. S. 
datum 
Rock 
penetra¬ 
tion 
Form¬ 
ation 
Variety and remarks 
65 
No. 1 
(C) 
(Brooklyn?) 
-89.83' 
-92.26' 
9.69' 
Ford. 
Garnetiferous granodio- 
rite, massive. 
66 
No. 2 
(D) 
(Brooklyn?) 
-86.0' 
-88.43' 
10.0' 
“ 
Garnetiferous gianodio- 
rite. 
67 
No. 3 
(F) 
(Brooklyn) 
-91.74' 
-93.17' 
12.12' 
“ 
Granodiorite, typical. 
68 
No. 4 
(E) 
“ ? 
-93.19' 
-95.62' 
10.0' 
Granodiorite. 
69 
No. 5 
(A) 
-89.92' 
-92.35' 
9.96' 
Mottled garnetiferous 
granodiorite, 1-inch core. 
70 
No. 6 
(B) 
-92.6' 
-95.03' 
10.0' 
Garnetiferous granodio¬ 
rite. 
71 
111 
? 
? 
“ 
Granodiorite, 1-inch core. 
( r 
replac 
rhis cc 
e No. 
re apparently belo 
or No. 2 above.) 
ngs here, 
but this 
number is 
not on a 
ny of the maps. It may 
b) Manhattan Pier. 
No. 1 
N. Y. W. side 
-124.9' 
-127.33' 
4.0' 
Manh. ? 
Mica schist, 1" core 
(D) 
unusual type. 
No. 2 
N. Y. E. side 
-117.9' 
-120.33' 
11.0' 
Inw’d. 
Typical coarse dolomitic 
(E) 
limestone, 1" core, solid 
crystalline. 
No. 4 
N. Y. (S. W. 
-96.25' 
-9S.6S' 
8.76' 
Manh. ? 
Very compact mica 
(G) 
cor.) 
schist, not typical. 
