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University of California. 



[Vol. 2. 



The city of Mazatlan, Mexico, is situated on a short drowned 

 valley. From here southward, the ocean is mainly bordered by 

 mountains, the bases of many of which rise directly from the sea. 

 At San Bias there is a representative of the low coastal plains of 

 Modern age, formed since the depression. The beautiful land- 

 locked harbor of Acapulco is another instance of a short deep 

 valley converted into a bay through the subsidence of the coast. 



From Cape Corrientes to Salina Cruz, close to the Guatemala 

 line, the coast is very precipitous and mountainous. Then there is 

 a radical change, for the mountains trend off to the east into the 

 interior, and across Guatemala, a broad low coastal plain lies next 

 the Pacific. This may be as much as 15 miles or more in width 

 and is backed by a high volcanic range, including the famous 

 "Volcano of Water" and the "Volcano of Fire," near the city of 

 New Gautemala. These volcanoes are of quite recent formation, 

 and their topography is markedly different from that of the greater 

 part of Mexican and Central American Mountain Ranges. While 

 sailing along the coast between San Francisco and Panama, I dis- 

 tinguished two principal types of mountain ranges. One is char- 

 acterized by distinct erosion topography, with sharp, rocky peaks, 

 deep valleys and numerous ravines. Most of the mountains seen 

 from the sea even in Central America are of this class. It is the 

 only one represented, except as to the peak of Chiriqui, on the 

 Isthmus of Panama. 



The other type is characterized by high, cone-shaped peaks, 

 remarkable for their long, slightly curved, but even slopes. The 

 smoothness of the topography in strong contrast to the roughness 

 of the other type, will appeal even to the unscientific observer as 

 indicating an extremely recent age. 



The low coastal plain of Gautemala extends to Acajutla in San 

 Salvador, where it has been bowed up about 40 feet by a slight 

 disturbance perhaps connected with the active volcano seen near by. 

 The sea has eroded a low cliff into the arched strata and revealed 

 a harder formation under the light-colored sand of which the low 

 coastal plain is largely composed. This lower formation I believe 

 to belong to another coastal plain which was largely submerged 

 and the present low coastal plain built on it. 



