Imautin.1 GEOLOGY OF COOK INLET REGION. 39 
ihinitna Bay, but from the great thickness exposed it is evident tied 
hey must extend thence a considerable distance. Rocks of similar 
lithologic character have been reported from the vicinity of Snug 
Harbor." Fossils are distributed throughout the entire thickness of 
the formation, and show the age to be middle Jurassic. 
A generalized section of the Enochkin formation is as follows: 
Generalized section & of Enochkin formation. 
Feet. 
park-drab shale with abundant limestone concretions and with numer- 
ous fossils (zone D) 1,283 
Concealed ; 25 
Sandy shale with many fossils (zone C) 50 
Concealed 20 
Shale with some sandstone 150 
Conglomerate 10 
Concealed 
Shale with several fossil bands (zone B) 50 
Concealed 
Shale with one or more fossil bands (zone A) 30 
Concealed 
Shale 12 
Coarse conglomerate 20 
1, 650+ 
The lowest bed is a basal conglomerate about 20 feet thick. The 
pebbles are large (averaging several inches in diameter) and were 
derived from crystalline rocks, principally granite. The shales at 
their very contact with the conglomerate are fossiliferous. 
The point at the south side of the entrance to the eastern arm of 
Enochkin Bay c shows several outcrops of shale, with several beds 
abundantly filled with fossils, each bed being from 10 to 25 inches 
thick. About 30 feet of shale is exposed. The strata immediately 
above and below are concealed, and there are no good exposures between 
this point and the contact 1 mile northeast, described above, nor for a 
distance of 1 mile below it. At the latter point good exposures again 
begin and are continued along the shore for a distance of about 3 
miles, the strata exposed in this interval being dark, sandy, fossilifer- 
ous shales. Fossils were collected from these zones, but were mixed in 
transportation, and it is consequently not possible to give the fauna I 
lists separately. The specimens of the combined faunas have been 
submitted to Dr. T. W. Stanton, who determined the following species 
and assigned the faunas to the middle Jurassic. 
« These beds were traced as far north as Snug Harbor during the summer of 1904. 
& The concealed intervals in this section are very large. The total thickness probably 
exceeds 3,000 feet. 
c On this point are also large masses (not in place) of brown sandy shale; there are 
numerous bowlders of this rock, but no exposures in place. The bowlders arc always 
near the basal contact of the Enochkin formation and can not have been transported far. 
The sandstones from which these probably came were seen during the summer of 1!><>4 in 
the region to the northward. 
