Notes on a geological section from Iguala to San Misuel Totolapa, 
STATE OF GUERRERO, MEXICO. 
BY CHARLES E. HaLL, 
(PLATES V € VD. 
(Presented by Mr. J, G. Aguilera, M. S, A.) 
The section here given begins at the town of Iguala, which is a sta- 
tion on the Mexico, Cuernavaca «€ Pacific Railway, 238 Kilometers 
south of the city of Mexico. 
Iguala is located ina broad valley tributary to the Cocula river, 
which is a tributary, from the North, of the Balsas river. 
The line of the section extends to the westward as far as Aguaca- 
te, (K. 63 of the section), crossing the higher country, from which 
point it bears to the southward, and gradually reaches the Balsas ri- 
ver valley at 96 Kilometers from Iguala. 
The section, as far as kilometer 64 west of Iguala, represents the 
southern extension of the table lands south of the volcanic disturban- 
ces, which are marked by the volcanic peaks of Popocatepetl and To- 
luca. From kilometer 96 to the Balsas river valley, there is a gradual 
decent along the line of section. 
NOTE:— 
The distances are given in kilometers from Iguala, four Kilometers being apro- 
ximately aspanish league and I have indicated every four Kilometers on the 
section, Thescale is on milimeter = 100 meters horizonlal (1 centimeter = 1 kilo- 
meter). The vertical scale one milimeter = 50 meters. 
