32 INTRODUCTION

to the minerals, rocks and fossils, and their distribution and relations
deciphered. The collection and critical examination of these materials
must, therefore, precede the areal work. After these investigations
have been made it is possible to group together those materials of
similar age and physical origin in what is known as a geological for-
mation, which may be represented by a single color upon the map.
This method of representation is of importance to the searcher after
information regarding the mineral wealth of the state, while the
descriptive text, explanatory of the geological map, will indicate the
various mineral substances which characterize each formation, and
will thus be a guide in the development of the various resources of
each district. At the same time the futility of attempting to develop
mineral products in a formation which has been shown by careful
geological investigation to be devoid of them will be at once apparent.
Innumerable instances might be cited where great sums have been
wasted by a fruitless search after economic substances which might
have been entirely obviated if geological maps had been available or
had been employed when available.

The ultimate platting of the geological data upon the large scale
topographic maps, described in a preceding paragraph, will disclose
the relations of the several geological formations to the topography
of the state and at the same time will make possible the exact loca-
tion of the various mineral products. The resulting geological maps
will also serve as agricultural maps, since, as will be shown later, each
geological formation gives rise to its own particular type of soil.

THE INVESTIGATION OF THE MINERAL RESOURCES.

A satisfactory description of the various mineral products can be
undertaken only after the detailed investigation of the mineralogical
characters of the geological formations has been made and their dis-
tribution upon the geological map has been platted, at least in a pre-
liminary way. It is the intention of the State Geological Survey, as
its work proceeds far enough to give it an insight into the various
mineral resources of the state, to treat each subject independently
and exhaustively. Among the various materials which will be thus