NOTES ON THE GEOLOGY OF EASTERN GUATEMALA 
AND NORTHWESTERN SPANISH HONDURAS" 
SIDNEY POWERS 
Troy, N.Y. 
CONTENTS 
INTRODUCTION 
GENERAL GEOLOGY 
GEOLOGY 
Spanish Honduras 
Guatemala 
British Honduras 
RECENT CHANGES OF LEVEL 
TECTONICS 
ILLUSTRATIONS 
Fic. 1.—Tectonic lines in Honduras and Guatemala, modified from Sapper 
(Eighth International Geographical Congress, 1904 [Washington, 1005], Fig. r). 
Fic. 2.—Map of the northwestern portion of Honduras. 
Fic. 3.—Relief map of Guatemala, showing the long Polochie—Lake 
Izabal Valley on the north, Motagua Valley in the center, the row of volcanoes 
facing the Pacific, and the broad plain at the Pacific Coast. The International 
Railroad runs from Puerto Barrios, on the Atlantic, up the Motagua Valley, 
past Guatemala City in the high plateaus to San Jose, on the Pacific. A 
branch line runs from Santa Maria northwestward to the Mexican boundary. 
Fic. 4.—Map of the eastern portion of Guatemala. 
INTRODUCTION 
The geology of Central America between the Isthmus of 
Tehuantepec and the line of the proposed Nicaragua Canal has been 
known only from the researches of Dr. Karl Sapper. These 
observations through a number of years have covered a vast amount 
of territory in a general way.’ A brief examination of the Atlantic 
‘ Published by permission of the Director, United States Geological Survey. 
2K. Sapper, ‘Uber Gebirgsbau und Boden des nérdlichen Mittelamerika” (with 
geological map of Guatemala), Peterm. Mitt., Erginzungsheft 27, Heft 127, 1899; 
“Gebirgsbau und Boden des siidlichen Mittelamerika” (with geological map of 
597 
