Memorial and Biographical History of Dallas County, Texas. Page: 138 of 1,110

HISTORY OF DALLAS COUNTY.

are seldom seen, owing to their rapid disintegration.
Usually they are seen only in ravines,
creeks or fresh diggings. They are of a fine
consistency, unconsolidated and apparently
unlaminated until exposed to the weather,
when their laminated character is developed.
They are light blue before atmospheric exposure,
but rapidly change into a dull yellow,
owing to the oxidation of the pyrites of iron
in them. Their chief accessory constituent
is lime in a chalky condition, and they are
more calcareous at the bottom than at the top.
Near the top of these and other exposures
there is to be seen a rapid transition into the
black, calcareous, clay soil, characteristic of
chalk and chalky clays whenever their excess
of lime comes in contact with vegetation.
They are m6re calcareous and fossiliferous at
their base.
The economic value of these chalky clay
marls is in the fact that they are the foundation
and source of the rich soil of the main
black, waxy prairie, the largest continuous
area of residual agricultural soil in the
United States, apparently inexhaustible in
fertility; for as the farmer plows deeper and
deeper he constantly turns to light the fertile
marls which renew the vitality of the surface.
These soils can be much improved by further
geologic study.
5. THE UPPER ARENACEOUS OR GLAUCONITIC
DIVISION.
This is the continuation of the Ponderosa
marls, exhibiting itself chiefly in northeastern
Texas and southwest Arkansas.

Dallas county also borders upon the Grand

prairie or Fort Worth section, the features
of which are reported at length by the State
Geologist, so far as studied; but as it comes
outside of our district, we omit it here.
INDIANS.
The beautiful and fertile section of Texas
now comprising the populous and wealthy
county of Dallas, was occupied by the Indians
when first approached by the white
settlers. While they were not as numerous
as in other sections, they were found scattered
through the timbers, especially on the
Trinity river, to such an extent as to cause
the earlier settlers much trouble and annoyance
as well as damage.
There have been many conjectures as to
the time this race of people had lived here,
but whether for a long or short period one
fact is said to be very evident, namely, that
the Indians were originally the first people
that ever trod the soil of Dallas county.
There are not here any traces of that memorable,
conjectured race of people; the moundbuilders,
as can be seen in other States. If
this mysterious and unknown, but evidently
intelligent prehistoric race had ever populated
this county, or even country, they would
have left some of their remarkable impressions,-some
traces,-yes, some "foot-prints
on the sands of time," as they left in other
sections of North America.
Whence the origin of this peculiar race
called the Indian, found here as well as in all
new countries of America, is certainly a very