38 REPORT OF NEW JERSEY STATE MUSEUM. 
of material and its installation was an educational one. Th 
effort was made, not only to display samples of the rocks 
minerals, ores, etc., of the State, but to show their distribu¬ 
tion, their value, the method of utilization, and in some in¬ 
stances, specimens of the articles made from them. Another 
part of the exhibit was designed to illustrate the work which 
the Survey had accomplished in investigation, and the dis¬ 
semination of information regarding the State. The way in 
which these results were accomplished may be shown by a 
brief description of the exhibit. 
Geology. A systematic collection of rocks, ores, minerals 
and fossils was arranged in a series of cases, to show in outline 
the geological structure and history of the State. Beginning 
with the extremely ancient rocks of the pre-Cambrian era, a 
suite of specimens was shown illustrating the main rock types 
belonging here. A small map showed the distribution in New 
Jersey of rocks of this era, and a brief descriptive label gave 
the important facts regarding the geography, culture and 
economic resources of the region underlain by them. The 
workable iron and zinc deposits of the State lie almost exclu¬ 
sively in these rocks, so that the specimens of iron and zinc 
ores, with maps showing the location of the mines, were placed 
here. So, too, the various steps in the processes by which 
the iron and zinc minerals crushed and separated by electrical 
methods from the accompanying waste rock, were illustrated 
by sets of specimens. Finally there were displayed specimens 
of the various minerals which are found so abundantly in 
rocks of this era at some localities, notably at Franklin Furn¬ 
ace. In this way all the information relating to the geography, 
geology, mineral resources and mineralogy of the pre-Cambrian 
rocks was grouped together and so arranged that the visitor 
might carry away a definite conception of these relationships. 
Following the pre-Cambrian rocks, came those belonging to 
the Paleozoic era. These are chiefly sandstones, shales and 
limestones, belonging to the Cambrian, Ordovician, Silurian 
and Devonian systems. The principal economic products are 
Portland cement rock, roofing slate, and limestone for lime. 
They contain but few valuable mineral specimens, but the 
fossil remains of the ancient life of this time are of interest 
to the layman, and of great importance to the geologist. 
