Deep Cores of Oahu — Stearns and Chamberlain 
159 
TABLE 1 ( Continued ) 
Description of Core from Ewa No. l Hole 
DEPTH 
(in feet) 
ROCK TYPE 
DESCRIPTIVE NOTES 
358-363 
Brown mud 
Pure dark-brown mud with irregular tubular cavities 
p 2 mm across lined with limonite. No bedding visible. 
Last 6 inches is light brown. 
363-364 
Gray sand 
Gray-brown fine sand; over 50% basaltic grains eroded 
from a basaltic terrane or water-laid lithic tuff deposit. 
No glass particles obvious. 
364-371 
Calcareous mud 
Calcareous mud with limonitic streaks. 
371-376 
Reef limestone 
Muddy fragmental reef limestone, much altered. 
376-383 
Calcareous mud 
White calcareous mud. 
383-394 
Reef limestone 
Muddy fragmental reef limestone probably broken by 
bit. 
394-401 
Mud and coral fragments 
Layers of mud and mixed mud and coral fragments. 
401-412 
Brown mud 
Brown mud with scarce limy grains. A 4-inch layer of 
fine weathered basaltic sand from 403.5 to 404 ft. 
412-415 
Reef limestone 
Muddy reef limestone, with about 1 ft of altered lime- 
stone at top with laminations. 
415-435 
White limy mud 
White chalky mud with a few hard chunks. Contains 
minute borings of marine organisms. Probably a 
chemical precipitate. Lumps of hard limestone at 424 
ft and from 426-435 ft. Some are altered coral 
fragments. 
435-444 
Reef limestone 
Recrystallized reef limestone and white mud. Transition 
into material above. Mostly fragments broken up by 
drilling ( ? ) . At 440 ft mud becomes browner and at 
444 ft becomes predominant over coral. 
444-453 
Brown mud and limestone 
fragments 
Mud and coral reef limestone fragments. 
453-464 
Gray mud 
Same as above but fewer rock fragments. Possibility that 
some rock fragments are chiefly crystallized calcite in 
place. 
464-464. 5 
Organic mud 
Brown layer with 1 -inch layer of black lignite at bottom. 
464.5-472 
Gray mud 
Gray lagoonal mud; in places 4 inches of it is hard 
cemented mud-limestone. Contains one oyster shell 
and a few other types of molluscs. 
472-493 
White mud 
White calcareous mud with hard crystalline calcite lumps 
toward the bottom. Spherical and oval grains suggest 
altered Foraminifera. 
493-497 
Reef breccia (?) 
Fragmental limestone containing large oyster shells and 
other molluscs. The mud matrix is darker than above. 
The whole deposit resembles a fine-grained reef talus 
deposit. 
497-572 
Reef limestone 
Fragments of reef limestone %-3 inches across, probably 
broken by bit; probably highly permeable structure. 
Oyster shell at 523 ft. Mostly recrystallized. At 535 - 
540 ft several zones of smaller sized fragments and 
white mud. Oyster at 546 ft. Porites at 545 ft. At 
545-555 ft much recognizable coral, less altered than 
above. 
