36 INTRODUCTION

opment of this industry, and it is the intention of the State Geological
Survey at an early date to take up a systematic investigation of the
coal-bearing beds of this portion of the state. Already enough has
been learned in the preliminary examination of the area to convince
the members of the survey that extensive deposits of coal exist there.

GOLD DEPOSITS. —There is undoubtedly a considerable volume of
gold scattered through the crystalline rocks of the Piedmont portion
of Maryland, but it has not hitherto been found in sufficient quantities
at any one point to give assurance of its being worked with profit by
present methods. It is not at all improbable, however, as the various
processes are improved, that the gold deposits of Maryland will come
to have much value, and it is certainly desirable that the character
and distribution of these gold ores should be fully studied by the
State Geological Survey. Such investigations are to-day being
accorded the gold deposits of the adjacent states where the outlook
can be considered to be little better than in Maryland.

SOAPSTONE. —Soapstone quarries have been opened from time to
time in the northern portion of the Piedmont area, and it is desirable
that the distribution of this material should be carefully determined.
Larger and more readily worked deposits may be discovered in the
careful investigation of the crystalline rocks, which will tend to very
largely develop this important industry. It is the intention of the
State Geological Survey to consider this matter as its work proceeds.

MINERAL PAINTS. —Mineral paints in several varieties have been
obtained in various portions of Maryland, and are to-day being worked
to some extent in the region between Baltimore and Washington.
These mineral paints are found in the old crystalline and in the recent
sedimentary rocks. It is probable that further investigations will
reveal other deposits and that this industry may receive much aid
from the work of the survey.

DIATOMACEOUS EARTH (Tripoli). —The deposits of diatomaceous
earth, sometimes known as infusorial earth or tripoli, extend as a
thick bed across the eastern and southern counties of Maryland and
have been worked with profit at several points in the latter area. As
the work of the State Geological Survey proceeds, the extent of these