178 ALASKAN MINERAL RESOURCES IN 1904. Lbubl. 259 
timbers. The coal in the face of the tunnel is solid and, though frozen, 
docs not break up greatly on exposure to the air. The seam is 5 feet 
thick and has two thin clay partings, one 1 foot from floor, the other 
about the middle of the vein. The roof is shaly sandstone, which 
stands well without timbers. The floor is hard clay shale. A few 
feet below this seam there is a second undeveloped seam two or three; 
feet thick. 
The next bed of importance is about 500 feet lower stratigraphically, 
the intervening beds being shales that contain four or five small, unim-j 
portant coal seams. This bed is probably the original Corwin vein,] 
and has yielded a considerable amount of coal. It has been developed! 
by a tunnel from the sea cliff and an air shaft from the level surface] 
above the cliff, which is about 75 feet above the sea. In the summer! 
of 1904 the entrance to the tunnel was closed by a great mass of ice, I 
the remnant of snow drifts formed during the preceding winter, andl 
the air shaft was rilled with water, so that the workings were inacces-j 
sible and the coal bed could not be measured. It is reported to have! 
a total thickness of 16 feet, of which 7 feet is clear coal, with no part- 
ings, while the remainder contains several partings and is without 
value. 
Below this bed there are shales for about 1,000 feet above the con] 
glomerate bed that forms Corwin Bluff. In this shale there arei 
eight veins of coal, indicated by croppings, which could not be exam- 
ined in detail, their exposures in the cliffs being inaccessible. Threei 
of these veins are over 4 feet thick. One of them, which immediately* 
overlies the conglomerate, appears from the sea to be about 30 feet I 
thick and to contain impure coal. Another, said to be about 12 feet I 
thick, and a third 4 feet thick are reported to yield clean coal of good 
quality. 
Immediately below the Corwin Bluff conglomerate and between 
it and a massive sandstone is an irregular bed, which is reported to; 
have produced about 500 tons of coal during one season. This bed 
has been affected by shearing movements of the inclosing strata. Ir 
other parts of the series the inclosing shales are soft beds which hav< 
yielded equally to shearing strains, so that the coal beds have remainec 
unaltered; but in this case, the conglomerate and sandstone beds bein£; 
rigid, the whole effect of such forces has been felt by the coal be( 
which lies between them. The coal bed appears in the face of th< 
bluff as a series of lenses. The coal itself shows evidence of shearing 
but is obtained in large pieces. Since this bed was worked the face o 
the bluti' has fallen down, making the coal inaccessible. 
The next bed of importance in the series outcrops in the sea elil 
about 1,000 feet east of Corwin Bluff, and is stratigraphically 40< 
feet below the conglomerate bed, the intervening strata being sand 
stones and shales containing many plant remains and one small coa 
bed below the irregular one noted above. The section of the coal be- 
