THE GLENEYRIE FORMATION AND ITS BEARING ON 
THE AGE OF THE FOUNTAIN FORMATION IN 
THE MANITOU REGION, COLORADO 
GEORGE I. FINLAY 
Colorado Springs, ‘Colo. 
The Paleozoic section to the east of Pike’s Peak, Colorado, in the 
Manitou region is composed of four members, as follows: (1) a basal 
Cambrian sandstone; (2) a limestone series, the lower half of which 
is Ordovician (the age of the upper half is still in doubt); (3) a 
fossil-bearing sandstone of Pennsylvanian age; and (4) the Fountain 
formation, arkose sandstones, grits and conglomerates, the lower 
members of which are almost certainly of Pennsylvanian age, while 
the upper members may in the end be definitely correlated with the 
Permian and Triassic. The purpose of the writer in the present 
paper is to describe the sandstone member, (3) in the series as given 
above. It has not previously been described. It contains the only 
identifiable plant remains of Pennsylvanian age which have been 
found thus far in the Rocky Mountain region. These fossils make 
possible its safe correlation with the Upper Carboniferous of the 
East. The Fountain beds appearing in the section next above can- 
not, therefore, be older than the Pennsylvanian, and the occurrence 
in them of brachiopods which have been recently found points to their 
being of Pennsylvanian age. 
Our knowledge of the Paleozoic section in the Manitou region 
warrants us in making the following statement with a large measure 
of confidence as to its correctness. Overlying the basal granite, 
which with its included schist and gneiss represents the Archean and 
Algonkian, there are found 50 feet of upper Cambrian sandstones. 
The lowest member of the Cambrian is an 11-foot band of white, 
fine-grained quartz feldspar sandstone. The succeeding layers going 
upward are stained by iron a deep red-brown, and they show irregu- 
lar green markings due to the presence of glauconite. It is the 
upper Cambrian which is represented. ‘The amount of lime increases 
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