518 SIDNEY POWERS 
inch in width. The age of the fossils was determined by Dr. 
E. O. Ulrich as probably Upper Mississippian or Lower Pennsyl- 
vanian. Excellent exposures of the same rock were seen in a 
quarry 7 miles inland from Puerto Barrios along the old line of 
the International Railways of Central America. The Pancajche 
fossils, a large species of Fusulina, of Pennsylvanian age according 
to the determination of Professor P. E. Raymond, were found in 
dense, bluish limestone interbedded with slate and with mica schist 
dipping 40°-80° S. to S.E. These rocks belong to the Santa Rosa 
formation of Sapper. . 
The Sierra de las Minas range is mapped by Sapper? as being 
composed, from south to north, of serpentine, crystalline schist 
and gneiss, granite (in part of range), Santa Rosa formation schist 
of Carboniferous age (as at Pancajche), and Carboniferous lime- 
stone. The belt mapped as serpentine coincides with a belt of very 
good quality white, crystalline marble which composes the south 
flank of the mountains and is now being quarried on an extensive 
scale 15 miles northwest of Zacapa (Fig. 1). The marble is said 
to be equal in quality to any in the United States. 
An unconformity is supposed to exist on the north side of the 
mountains between the crystalline rocks and the fossiliferous Santa 
Rosa formation schists. The evidence of this unconformity is 
stated by Sapper to be the presence of occasional pebbles of crystal- 
line schist as large as nuts in the Santa Rosa schists. On the 
strength of this evidence Sapper places the crystalline schists in the 
pre-Cambrian, although he admits that the rocks cannot always 
be distinguished. Confirmatory evidence of the existence of this 
unconformity is needed, for the degree of metamorphism of the 
rocks increases from north to.south in both Guatemala and Hon- 
duras. Mountain-building movements at the close of the Paleozoic 
will account for all the variations in the degree of metamorphism 
of the Paleozoic rocks. Intensely metamorphosed and recrystal- 
™ Mitt. Geogr. Gesell. Hamburg, XVII (1901), with lists of fossils collected by him. 
2 Peterm. Mitt., Erginzungsheft 27, Heft 127, 1899; Mutt. Geogr. Ges. Hamburg, 
XVII (1901). 
3 Mitt. Geogr. Gesell. Hamburg, XVII (1901); Doilfus et Mont-Serrat (op. cit.) 
also report an unconformity. 
