HO 
Some of the bands carry iron pyrites, and weather rusty-coloured. The 
clear and white, or light coloured bands appear to be fit for glass making. 
The outcrop of this formation near the Ottawa River front, at the Rock- 
land Mills, belongs to the lower portion of the Potsdam. The higher 
beds of the formation in the Ottawa Valley are finer grained, and have 
the grains of quartz in the sandstone less coherent, and the beds them- 
selves are less massive and reduced in thickness, often presenting the 
well known tracks of Protichnites as at Montebello, Papineauville and 
above that again,* eight miles below the mouth of the South Indian 
River. 
The Calciferous and Chazy. 
These two formations occupy their regular and respective positions, 
one below the other, both as regards their geological and geographical 
relations at Rockland. The zone of farming or pasture land, between 
tne escarpment at the quarries and the town, is occupied by these two 
formations, whilst the soil is made up to a great extent of the debris of 
the Chazy, which is the softest and most easily denuded and disintegrated 
formation in the district. 
None of the characteristic fossils of the Calciferous formation were 
found on this occasion, but at the turn of the road on the hillside about 
i^ miles south of Rockland the typical shales of the Chazy formation 
crop out and are fossiliferous. These overlie the fine-grained and 
compact limestones, on which Mr. Edwards' celebrated stork and 
breeding stables are built. 
These limestones are characterized by the presence of concretions 
or inclusionsof irregular massesof pink calcite varying in size andintensity 
of colour. There are two or three bands of these limestones, which, both 
in Nepean and elsewhere, have been utilized or described as "cement- 
rock." This is the same band of limestone which crops out at the Hull 
cement quarries, Skead's mill, Ont., also at Hog's Back, and again on a 
lot the property of Mr. T. M. Clark, of New Edinburgh close to 
Hemlock Lake. 
The following species of fossils have been recognized by the writer 
in the dark and chocolate coloured and purple, calcareo-argillaceous 
'('.eulogy of Canada, 1S63, p. 94. 
