32 



University of California Publications in Geology 



[Vol. 10 



UPPER HORIZON. 



Fig. 6 



INTERMEDIATE HORIZON. 



DEEP HORIZON. 

 PiiT. 8 



LIME 31 



CONTACT 

 METAMORPHIC ROCK 



77777 



Generalized plans of ore chimney at Dolores Mine, Matehuala, San Luis 

 Potosi, Mexico. After Basil Preseott, Econ. Geol., vol. 10, p. 65, 1915. 



