Ohio Natin-al Gas Fields. — Bozviiockcr. 231 
eighteen miles farther east, 1160 feet, and at McConnellsville, 
forty miles east of Lancaster, 1712 feet. This is an average 
increase of twenty-five feet per mile, and if this rate should 
continue until the Ohio river is reached, it would mean a thick- 
ness of over 2,500 feet for the formation. This is in harmony 
with a test made farther north near East Liverpool where these 
shales were penetrated to a depth of 2,600 feet without reach- 
ing their base. It is apparent from this fact that it is prac- 
tically useless to attempt to develop an oil or gas field in the 
Clinton in eastern Ohio; and further it may now be regarded 
as having been demonstrated by the drill that when the Berea 
grit has been passed in this territory all hope of finding an oil 
or gas rock is gone. 
STRUCTURE OF THE SOUTHERN PORTION OF 
THE KLAMATH MOUNTAINS, CALIFORNIA. 
By OscAK H. Hershey, Berkeley, California. 
In the Klamath legion, the observation of strikes and dips, 
unless followed industriously for a long period and over a 
broad extent of territory, is a waste of time, as it leads to but 
one conclusion, namely that the entire region has been broken 
up by small irregular folds and faults which mask the true 
character of the structure. In certain areas the dips will be 
prevailingly in one direction, generally easterly, and give the 
observer the impression that the formation as a whole is in- 
clined in that direction, whereas the easterly dips are due solely 
to a vast number of small, easterly tilted fault blocks. 
The only satisfactory method of obtaining a correct appre- 
ciation of the structure in a broad sense, which the writer has 
found available in the Klamath region, is the persistent follow- 
ing of contacts between different formations. After several 
years devoted to that kind of work, one acquires the habit of 
forming mental pictures of the individual formations as single 
great masses of unbroken rock, disregarding the innumerable 
minor dislocations. It is of this major structure that I propose 
to treat in this paper. 
The present degree of deformation of the rocks of the 
Klamath region is the result of movements at different periods 
