94 ALASKAN MINERAL RESOURCES IN 1906. 
and in the soil. The nearest outcrops of hard rock are sandstones J 
or graywackes, probably the same as those on Wingham Island and 1 
in Ragged Mountain, and if so of pre-Tertiary age. It seems almost 1 
certain that the oil came from these rocks. Seepages were also seen 1 
near the head of Mirror Slough at the base of Ragged Mountain. The 1 
oil here reaches the surface from the soil, which is underlain either by ] 
glacial drift or by talus or landslide debris. The underlying rocks I 
are probably the slate or graywacke referred to above. Another 1 
seepage about 1 mile south of this point, in the canyon immediately ] 
north of Bald Mountain, was visited by the writer. The oil was here j 
seen oozing in small quantities directly from the joints and bedding 
planes of the steeply dipping slates and graywackes. 
Oil is reported to have been seen in large amounts at the time of 
the earthquake in September, 1899, on the surface of the water of 
the small ponds and the creek at the south end of Katalla. The 
surface material consists of rock debris, largely from Ragged Moun- 
tain, underlain by the soft shales previously described as the Katalla 
formation. 
Numerous and copious seepages are to be seen at the head of 
Katalla Slough. The oil impregnates the soil very completely at 
many points and has accumulated in large amounts on the surface, 
but these accumulations are chiefly of oil and are not residues, as at 
the California brea deposits. No outcrops are near, but the under- 
lying rock is •almost certainly the soft shale referred to above, and 
probably has a steep dip. 
On the west slope of the valley of Redwood Creek, about 1J miles 
northwest of the mouth of the creek and near a well, oil can be seen 
coining directly from soft fissile iron-stained shales. The shale has 
been broken into small angular fragments and recemented by ferrugi- 
nous material. This condition is common at or near seepages in 
these shales, but we do not know whether it is a surface condition 
connected with erosion or whether it indicates crushing of the rocks 
at a depth below the surface during the process of folding or faulting. 
Here, as at many other seepages, sulphur springs are associated with 
the oil. Another seepage was seen near the headwaters of Redwood 
Creek. 
It is reported that oil may be seen at low tide in the beach sands 
on the north shore of Strawberry Harbor. The rocks in the vicinity 
are sandstone and shale, probably belonging much higher in the 
stratigraphic column than the soft shale at the seepages previously 
described. 
There are several seepages along the wagon road which leads from 
the head of Katalla Slough to the mouth of Bering River. Two of 
them are located about a mile and a half west of Burls Creek and 
close to the road. The amount of oil at one of these is large. The 
