Tae OccuRRENCE OF CONGLOMERATE AND SANDSTONE OF Post- 
GLACIAL ORIGIN IN JEFFERSON CouNTY, INDIANA: 
By GLENN CULBERTSON. 
The city of Madison, Jefferson County, Indiana, has been built on a 
great sand and gravel bar. This bar is approximately three miles long, 
from a quarter to a half mile wide, and of varying depth up to sixty or 
eighty feet. It is composed quite largely of sand, gravel and pebbles of 
glacial origin, water worn and deposited by the Ohio river. The bar de- 
posit was very probably formed contemporaneously with the “second bot- 
toms” or the first terrace of the Ohio river, and during the time of flooded 
waters as the later glaciers were melting. 
Crooked creek, a stream some eight or ten miles long, which in glacial 
or preglacial times emptied into the Ohio near what is now the upper part 
of the city was deflected by these deposits, and now flows approximately 
parallel to the Ohio river for some three miles, emptying into the larger 
stream at a distance below the pumping station of the Southeastern Hos- 
pitai for the Insane. 
It is along the banks and on the slope to the south of Crooked creel 
— 
ca, 
Fig. 1. 
Ideal cross section of gravel bars and conglomerate deposits. Width of bar 
a b equals one-fourth mile; height m n equals 60 feet. 
(c) Bed of Crooked creek. 
(d) Position of thickest conglomerate and sandstone deposits, irregularly 
placed. 
(e) and (s) Other irregularly placed deposits of indurated rocks. 
(ab) Low water mark Ohio river. 
