Deep Cores of Oahu — Stearns and Chamberlain 
161 
TABLE 1 ( Continued ) 
Description of Core from Ewa No. l Hole 
DEPTH 
(in feet) 
rock type 
DESCRIPTIVE NOTES 
851-858 
Olive black mud 
Highly fossiliferous mud with sharp basal contact. 
858-931 
Gray and black mud 
Gray calcareous mud with no nodules and some shells. 
At 874 ft a !/ 2 -inch layer of basaltic sand with some 
layers of gray-black and black mud, highly fossiliferous 
and full of basaltic grains and microscopic fossils. 
Some silt layers at 911-921 ft. 
931-942 
Olive black mud 
Similar to above, poor in fossils, but uniformly dark.. 
942-948 
Gray mud 
Similar to above except for color. 
948-950 
Basaltic sand 
Indurated basaltic sand and clay; basalt grains diverse 
and weathered. 
950-966 
Gray mud 
Indurated gray calcareous mud. No fossils observed. 
966-979 
Brown mud 
Indurated brownish-black mud. 
979-980.5 
Brown sand 
Indurated fine basaltic sand and silt. 
980.5-981.5 
Brown clay 
Indurated brown silty clay. 
981.5-984 
Brown sand and gravel 
Indurated brown basaltic sand with scarce pebbles up 
to p 2 inch across. 
984-991 
Brown mud 
Indurated brown fossiliferous silty clay containing a 
1-inch piece of Poriies coral embedded in clay at 
988 and 990 ft. 
991-1015 
Gray mud 
Indurated gray mud with limy zones and nodules. Oyster 
at 1,004 ft and more at 1,009 ft. Another oyster at 
1,015 ft. 
1015-1043 
Tan and gray mud 
Hard very indurated brown mud, in places fossiliferous. 
Oyster shell, other fossils at 1,025 ft. 
1043-1054 
Brown sand 
Typical brown basaltic indurated sand ; grains mostly 
weathered limonite stained areas. 
1054-1061.5 
Conglomerate 
Cobbles and pebbles up to 6 inches across, mostly dense 
blue basalt with a layer of silty clay, sand, and small 
pebbles at 1,055.5-1,057 ft. The sandy layers may be 
the matrix washed by drilling. Sand again at 1,061- 
1,061.5 ft. 
1061.5-1072 
Brown clay 
Well indurated brown silty clay. No fossils noted. 
Basaltic grains visible. Becomes sandy at 1,071 ft for 
1 ft. 
1072-1077.5 
Weathered basalt 
Weathered basaltic aa clinker typical of a subsoil, con- 
sisting of partly decomposed clinker in a softer matrix, 
with creamy montmorillonite in the interstices. The 
top soil has been eroded away by the stream which 
emplaced the basal conglomerate. 
1077.5-1088.3 
Basalt 
Solid basalt with large stretched vesicles typical of an aa 
lava. One unbroken core is 31 V 2 inches long. The 
rock is nonporphyritic. 
1088.3-1089 
Basaltic clinker 
Partly weathered red clinker. 
1089-1097 
Basaltic clinker 
Red aa clinker. 
1097-1107 
Pahoehoe 
Very vesicular olivine pahoehoe with slightly weathered 
surface. 
