Indiana Natural Gas Field. — Leverett. 15 
A broad, elevated, nearly level-topped tract, to which Prof. 
Orton has given the names "arrested anticlinal'' and "terrace,'' 
enters Indiana in its southeastern corner and passes north- 
west with a gradual decline in altitude to southern Wabash 
and Miami counties and central Howard county. It underlies 
the greater part of the following counties : Dearborn, Franklin 
Rush, Fayette, Union, Wayne, Henry, Hancock, Hamilton, 
Madison, Delaware, western Randoljih, western Jay, Blackford, 
Grant, Tipton, Howard, southern Miami and southern Wabash. 
The highest ascertained points which have come to the 
Avriter's knowledge are at Brookville and Cambridge City — 175 
and 176 feet A. T. ; and the lowest are in Tipton and Howard 
counties, near the northwestern end of this elevated table, 
Avhere several borings show the Trenton to be 100-140 feet be- 
low tide. That the line of strike lies in a S.E. — N. W. direc- 
tion is evident from the fact that any line of the length, for in- 
stance, of the distance from Cambridge City to Kokomo (about 
75 miles,) taken in any other direction from Cambridge City 
than a general S. E. or N. W. course, would show a much great- 
er descent. For example, at Bluffton, 75 miles north from 
Cambridge City,the altitude is 230 feet below tide, and at Dan- 
ville, some 75-80 miles west, 518 feet below tide, while at Ko- 
komo it is only 83 feet below tide. Amboy, in Miami county, 
and La Fontaine in Wabash county, each about 75 miles from 
Cambridge City, show but little more descent than Kokomo, 
thus demonstrating that the level-topped phase of the Trenton 
here occupies a breadth of about 30 miles. West from Koko- 
mo or east from La Fontaine a rapid descent soon begins, as 
the table shows. 
In Miami and Cass counties the Trenton makes a rapid de- 
scent toward the northwest as is shown by borings along the 
Wabash river, its altitude at Peru being 260 feet, and at Lo- 
gansport 344 feet below tide. At Royal Center, in northern 
Cass county, the Trenton stands markedly higher than at Lo- 
gansport, its altitude being but 190 feet below tide. 
East-to-west axis of upheaval. — There is probably an axis 
of upheaval running from Royal Center west to Monon and 
thence to Kentland, Indiana. No borings of which we have 
the record have struck the Trenton along this line, but the 
' Geology of Ohio, vol. vi, p. 94. 
