GEOLOGY. 49 
from the surface, ind was unable to pass through it. The fol- 
lowing is a statement of the different strata encountered in the 
Stockton well, and the thickness of each in feet, beginning at 
the surface: ; 
Black loam, 6; red clay, 6; dark-red clay and sand,-18; blue 
clay, mica, and sand, 10; blue clay, hard, highly stratified, 4; 
blue clay, mica, and sand, 3; blue clay, hard, and highly strati- 
fied, 4; green sandstone and clay, very hard, 29; blue clay, 
sand, and gravel, slightly impregnated with gold, 2; blue clay, 
sand, and gravel, 18 (100); green sandstone, clay, and mica, 
hard, 15; fine gravel, 5; gray quicksand, 15; blue clay, 8; 
gray sand and clay, 27; dark-blue clay and sand, 33 (208); 
coarse gravel and pebble-stone, 27; blue clay, 7; gray sand, 
13; blue clay and sand conglomerated, 12; light-gray sand, 3 ; 
blue clay, 6; light sand, 9; blue clay, 1; fine gray sand, 12; 
dark clay, 2; fine gray sand, 7 (302) ; clay and sand, 10; coarse 
gray sand, 1; light clay, 19; coarse sand, 14. (Norz—At 
340 feet, in this stratum of sand, a red-wood'‘stump was found, 
and a stream of water ascended to within three feet of the 
surface.) Light clay, 8; fine gray sand, 11; light clay, 203; 
coarse gray sand, 20; clay, very hard, 4 (400); gray sand and 
clay, 5; clay, 20; coarse gray sand, 3; light clay, 15; fine 
gray sand, 4; light clay and sand, 1; coarse gray sand and 
clay, 1; light-blue clay, 11; gray sand and ‘clay, 7; light-blue 
clay, 15; fine gravel, 1; light-blue clay and gravel, 13 (496); 
fine gravel, 25; clay and sand, 2; sand and clay, 5; coarse 
gray sand, 7; fine blue clay, 8; fine gray sand, 42. (Norr.— 
At 560 feet, in this stratum of sand, obtained a stream of water, 
rising five feet above the surface.) Gray sand and clay, 15 
(600); light clay and sand, 6; fine gray sand, 24; clay and 
sand, 3; fine sand, 9; fine gravel, 3; fine gray sand, 5; coarse 
sand, 2; blue clay and sand, 8; gray sand and clay, 8; clay 
and sand, 5; fine gray sand, 10; clay, 5; coarse gray sand, 2; 
fine light-blue clay, 4; hard, chocolate-colored clay, 2; blue 
clay, 2 (698) ; fine gray sand, 30; clay and sand, 8; gray sand, 
4; light clay, 10; coarse sand, 6; blue clay, 4; dark clay, very 
2 
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