530 WILBUR G. FOVE 
diameter were picked up in the stream bed. A granodiorite col- 
lected from this vicinity has approximately the following composi- 
tion: 
Percentage y Percentage 
eOligoclasehmre aa er: TSOM MED IORIEE acres ctl araees 4 
Orthoclases.. 2... 20  Hornblende........ I 
Quartz ses eee 25 — 
100 
Rocks from the vicinity of Nueva Armenia.—Hot springs in the 
hills 5 miles south of Nueva Armenia and 13 miles east of the 
Tropical Timber Company’s railroad well up through tonalites 
and have kaolinized these rocks extensively. The fresh tonalite 
is a light-gray rock consisting of oligoclase, quartz, and hornblende. 
Gneissic varieties of the tonalite are found associated with coarse- 
grained diorites composed of oligoclase and hornblende. One 
specimen of the diorite shows a small amount of biotite. 
Summary.—The igneous and metamorphic rocks collected from 
the province of Atlantida, Honduras, include the following types: 
Granular rocks 
Granodiorite 
Tonalite 
Biotite tonalite 
Pegmatite tonalite 
Diorite 
Augite diorite 
Gabbro 
Dioritic gabbro 
Wehrlite 
Cryptocrystalline and glassy rocks 
Aporhyolite 
Felsite and agglomerate 
Tonalite porphyry 
Felsodacite and agglomerate 
Trachyandesite 
Olivine basalt, agglomerate, and tuff 
Metamorphic rocks 
Dioritic orthogneiss 
Epidote orthogneiss 
Actinolite gneiss 
Hornblendite 
Biotite schist 
Quartzite 
