wllibb.] COAL OF CAPE LISBURNE REGION. 177 
probably continues northeastward for an undetermined distance, since 
it is known to occur at Wainwright Inlet, 120 miles beyond Cape 
Beaufort, where it contains coal seams and has yielded fossils. 
rhroughout this distance coal fragments are found on the beach, 
where they have been pushed up by the ice, and pieces of coal have 
ilso been dredged up from the sea floor. Similar coals are reported 
o occur at the headwaters of the Colville and Ikpikpuk (Chipp) rivers, 
300 miles east of Cape Lisburne. 
The southern boundary of the coal-bearing formation runs south- 
eastward from the coast for about 10 miles, beyond which point it 
probably turns southward. Coal is reported in the interior 20 miles 
■south of Cape Beaufort, so that it is safe to say that the area of coal 
and in the Lisburne region is not less than 300 square miles, and is 
probably very much more than that. 
The topography of this field consists of low rounded hills and ridges, 
isually less than 600 feet in elevation. The ridges and drainage are 
ietermined by the bed rock structure. 
Investigations the past season indicate that there are not less than 
10 coal beds in the formation, aggregating about 150 feet of coal, and 
me croppings of many other beds have probably been overlooked, 
rhe coal beds, however, are undeveloped, and exact measurements 
were in most cases impossible. Coal has been mined from a group of 
Deds at Corwin Bluff and from another at Thetis mine, and croppings 
3f coal have also been observed at many other places, the first discov- 
eries being near Cape Beaufort. 
Corwin group. — Corwin Bluff, a sea cliff 200 feet high, is about 28 
miles east of Cape Lisburne. The highest part of the bluff rises sheer 
from the water, but about half a mile west of it there are narrow 
rocky beaches along the foot of the cliff, and a few hundred yards 
east there is a short sand beach at the mouth of a small creek. The 
bluff is at the seaward end of a ridge formed by the cropping of the 
conglomerate bed which has been already noted as giving a definite 
key to the stratigraphy. The coal beds of the Corwin group are 
near this bluff and stratigraphically lie both above and below the 
conglomerate. They strike N. 75° W., and dip SW. from 80° to 40°. 
The highest coal seam noted in the series outcrops in the sea cliff 1 § 
miles west of Corwin Bluff. It is exposed by a recent rock slide from 
the cliff' and contains 4i feet of coal without partings. The roof and 
floor are soft shales or shaty sandstones. 
A second seam, which has yielded some coal, is about 1,000 feet 
lower stratigraphically, the intervening beds being shales, which contain 
several coal seams either too small or too impure to be of value. This 
bed outcrops in the sea cliff three-fourths of a mile west of the Corwin 
Bluff, and is developed by a tunnel about 40 feel long, driven without 
Bull. 259—05 12 
