THE GLENEYVRIE FORMATION 589 
formation, making use of the name of the locality in which the best 
exposures are met. The Gleneyrie sandstone is a strong rock 
to resist weathering, and the weaker overlying Fountain grits have been 
stripped back down the dip for some distance from their outcropping 
edge. 
The Fountain formation next above in the series, resting on the 
Gleneyrie sandstone and separated from it by an unconformity 
with overlap, has a thickness of over a thousand feet. The forma- 
tion is made up of arkose sandstones, grits and conglomerates, red, 
vermilion, maroon, and occasionally white. Dr. Whitman Cross, 
who first used the name in the Pike’s Peak folio, assigned the Fountain 
beds to the Carboniferous. It is clear that in the Manitou region, 
since they overlie the Gleneyrie sandstone, they are not earlier 
than the Pennsylvanian. Fossils from the Fountain are extremely 
rare, and only two genera, brachiopods, have been found in the 
Manitou region. ‘They occur 200 feet above the base of the forma- 
tion in a three-foot layer of red, fine-grained, shaly sandstone. Good 
exposures are met above the stone house in Quarry Canyon. Here 
shells of Orbiculoidea are not hard to find. Dr. G. H. Girty has- 
kindly examined the specimens and referred them tentatively to Orbic- 
uloidea manhattanensis. With them a single productoid shell, resem- 
bling Marginifera ingrata, has been collected, but the specimen is not 
sufficiently good for accurate determination. Orbiculoidea Man- 
hattanensis has a wider range than the Carboniferous, but its occur- 
rence at this horizon points strongly to the Pennsylvanian age of the 
Fountain beds near Manitou. ‘The “Saurian”’ limestone conglom- 
erate of Triassic age, so well developed in the San Juan Mountains — 
of southwestern Colorado, is not known along the Front Range. For 
the final proofs as to whether any of the upper layers of the Fountain 
are to be referred to the Permian or to the Triassic we must await the 
results of such studies as Dr. Williston has been conducting in the 
Canyon City field. 
