Ulier] COAL OF CAPE LISBUKNE REGION. 175 
f the cliffs at Cape Thompson, and the main mass of the Lisburne 
mountains. The series consists of divers beds which fall into three 
[roups: (1) A lower group consisting of slates, shales, and limestones, 
pntaining several coal beds and yielding Paleozoic fossil plants; (2) a 
[ledian group of black cherts, slates, shales, and cherty limestones con- 
fining marine bivalve fossils, the most common being an aviculopec- 
en; (3) an upper group of massive limestones of great thickness, 
hade up largely of coral, and seeming to shade off into massive white 
herts. 
The shaly members are often closely crumpled, while the more 
passive beds present broad, open folds complicated by frequent thrust 
aults, making the stratigraphy difficult to decipher. The prevailing 
tructures, indicated by strikes and fault planes, seem to extend south- 
astward nearly parallel to the trend of the Lisburne Range. The 
otal thickness of the coal-bearing member is not very great, probably 
iot exceeding a few hundred feet, though data for a satisfactory esti- 
oate of thickness are wanting on account of the intense crumpling to 
yhich the beds have been subjected. Fossil plants of a type common 
n the Paleozoic coal beds of the eastern United States have been 
ound in the black slates associated with the coal. 
MESOZOIC FORMATIONS. 
The relation of the Paleozoic to the Mesozoic rocks could not be 
letermined, for, at the contact, faulting has brought older beds above 
he younger. 
The Mesozoic rocks occur on the coast about 3 miles east of (ape 
lisburne and extend beyond the limits of the area covered by this 
nvestigation. They consist of two members, of which the older is 
oal-bearing while the younger is not only destitute of coal but also 
>f fossils. 
The coal-bearing member, which has been called the Corwin forma- 
ion, begins on the coast line about 26 miles east of Cape Lisburne and 
tbout 2 miles west of Corwin Bluff. From this point it extends 
eastward to and beyond Cape Beaufort, the eastern limit of the area 
comprised in this investigation. This formation consists of rather 
:hin-bedded shales, sandstones, and conglomerates. The shales, which 
form the greater part of the section, vary fron^greenish-brown calca- 
reous to black carbonaceous beds, and in texture from mud stones to 
ine-grained sandy shales. 
The sandstones occur at infrequent intervals through the forma- 
tion, in beds usually less than 10 feet in thickness. Their outcrops 
form low ridges, which are easily traceable over eroded areas. The con- 
glomerates are made up mainly of quartz and chert pebbles, ranging in 
liameter from one-half to 4 inches. A conglomerate bed about 15 feci 
thick, which reaches the coast at Corwin Bluff, makes a distinct ridge 
