MAR8TERS, PHYSIOGRAPHY OF THE PERUVIAN A2WES 227 



geology of mining districts, data concerning irrigation projects, under- 

 ground waters, etc. More than two hundred bulletins have been pub- 

 lished by this department. While much information exists in the series 

 of publications, it is unfortunate that no attempt has ever been made to 

 correlate it with a view to preparing at least a preliminary geological map 

 of the more important mining centers of the republic. So far as I am 

 aware, the only attempt to correlate the formations in distinct parts of 

 the republic was recently made by Dr. G. Steinman for the Cordillera an-.] 

 by the writer for the formations of the coastal plains as they appear in 

 northern, central and southern Peru. Hence we may say that, while there 

 are sources of information relative to the geology and geography of the 

 Peruvian Cordillera, in no publication, so far as I am aware, has any 

 attempt been made to give even a skeleton outline of the probable physio- 

 graphic history of any section of the Ancles. 



Let us now see if, from the information to be gleaned from the early 

 writers and especially the map of Eaimondi, combined with the observa- 

 tions of the writer, we may be able to get a concise picture of the 

 geography and at least a glimpse into the geology of a portion of the 

 Peruvian Andes. 



The Eepublic of Peru occupies an area approaching 2,000,000 square 

 kilometers; it extends from 0° to 20° S. latitude and from 64° to 84° W. 

 longitude; its coast line is approximately 1,500 miles long, and it pos- 

 sesses all the varieties of climate from typically tropical conditions in the 

 north to cold temperate in the south and in the higher parts of the 

 Andean Highlands. One need not go beyond the confines of the Inca 

 Eepublic to find any of the variations between the extremes mentioned. 

 One may leave Lima under a semi-tropical sun and, in the course of a few 

 hours by rail, be riding over a snow-covered Puno. As soon as he reaches 

 the montana, or the wooded part of the eastern slope of the east range, he 

 passes immediately into warm temperate and tropical climates. 



TOPOGKAPHIC PPtOVINCES OF PERU 



The distinct topographic and physiographic provinces of Peru are well 

 defined. They may be summarized as follows : 



1. Coastal Plains. 



2. "West Slope and West Eange of the Andes. 



3. Highland Plateau, or Intercordilleran Belt, and its associated sec- 

 ondary ranges. 



4. Eastern Eange. 



5. Eastern Slope and Lowlands. 



