362 CHARLES S. PROSSER 



is drawn at the same horizon as the top of Zone 16 in the writer's 

 section, which gives a thickness of 8 feet 7 inches for the Spring- 

 field or 8 feet as measured by Professor Bownocker. 



SECTION NEAR LAUREL, INDIAN \ 



In the foregoing sections the correlation of the terranes referred 

 to the Osgood beds and the Laurel limestone, both of which were 

 named by Dr. Foerste, 1 was decided upon after visiting Laurel, 

 Indiana, and studying some of his sections in that typical region. 

 A section at one of these localities, in a somewhat condensed form, 

 is given below. The section is on the bank of a stream at a locality 

 known as Derbyshire Falls, on the C. J. Valkenburg farm, nearly 

 3 miles southwest of Laurel and some 47 miles southwest of the 

 Lewisburg Stone Co. quarry. A section of the Laurel limestone, 

 Osgood beds, and Clinton limestone measured at this locality and 

 the Lower Derbyshire Falls was published by Dr. Foerste in 1898. 2 

 The measurements in the following section are those of the writer 

 and his assistant, Mr. Kenneth Cottingham; but the classification 

 is in accordance with that of Dr. Foerste, except where differences 

 are noted: 



Derbyshire Falls Section 



Thickness thickness 



No. Feet Inches Feet Inches 



iS. Laurel limestone. — This limestone is shown in 

 the old quarry just across the quarry road to 

 the south of Derbyshire Falls and this zone 

 extends to the top of the quarry wall. It is 

 light gray, as weathered, rather thin-bedded, 

 the layers varying from 2 to S inches in thick- 

 ness. There are also at least 3 chert layers 

 ranging from 1 to 3 inches in thickness 4 7 5a o 



1 Osgood beds: Indiana Department of Geology and Xatitra! Resources, 2ist Annual 

 Report (1897), pp. 217, 227-29. 



Laurel limestone: Journal of the Cincinnati Society of Natural History, XYIII 

 (February, 1S96), pp. 190, 191, and Indiana Department of Geology and Natural 

 Resources, -ist Annual Report (1S97), pp. 217, 230, 231. 



2 Indiana Department of Geology and Natural Resources. 22(1 Annual Report (1S9S), 

 pp. 244, 245. An illustration of Derbyshire Falls is given on PL XVI. which faces 

 p. -44- 



