GEOLOGY OF GUATEMALA AND SPANISH HONDURAS 509 
form a region of little relief. A belt of gently folded Cretaceous 
and Oligocene strata, principally limestones with an east-west 
trend, separates the lowlands on the north from the high mountain 
ranges in the south. The relief of the mountains carved in rocks 
90° ae" 
92" 
° Progreso ( 
[rms LEGEND 
x xx Volcanoes 
| odche A —— Lunes of Yulcanism 
i 
sereseee Miocene Folding 
«occ Late Carboniferous Folding 
---- Pre-Carboniferous(?) folding 
) [4 Detail Maps 
orora/| 
9 ; SCALE 
a q 9 50 100 200Km. 
So); °°, 
‘ jee 
Eco 7% 4 34m Creek GULF 
J: lav” HONDURAS 
: P Bomace 
io* cote® Froors Se ne = 
4 
ios arf? Uta Ar 
Fic. 1.—Tectonic lines in Honduras and Guatemala, modified from Sapper 
(Eighth International Geographical Congress, 1904 [Washington, 1905], Fig. 1). 
of these ages is of the order of 1,000 to 2,000 feet. Mountains of 
metamorphic and intrusive rocks forming conspicuous parallel - 
ranges extend from southwestern Mexico and central Guatemala 
through northern Honduras and meet the coast at an angle on the 
south side of the Gulf of Honduras. The relief of the mountains 
