History of Linn County Iowa

irth

. It was the name first applied to the great treeless plains of North America b

he prairies. Different theories have been advanced, but the int

wrote; "hers the first shores washed by the ocean that enveloped all the earth besides; and while Europe was represented only by

vin, state geologist, says that "geological records, untampered with, and unimpeachable, declare that for uncounted years Iowa, together with the great va

tion of the ice in what is known as the glacia

was not invaded by glaciers. Allamakee, parts of Jackson, Dubuque, Clayton, Fayette, and Winneshiek counties belong to the driftless area. During the last two decades deep wells have been bored through the loose surface deposit, and down into the underlying rocks. The record of these wells shows that the rock surface is very u

liffs that rise almost vertically from three to four hundred feet, while from the summit of the cliffs the land rises gradually to the crest of the divide, three, four or five miles back from the stream. Tributary streams cut the lateral slopes and canyon walls at intervals. These again have tributaries of the second order. In such a region a

They are not oxidized or leached, but retain the carbonates and other soluble constituents that contribute so largely to the growth of plants. The physical condition of the materials is ideal, rendering the soil porous, facilitating the distribution of moisture, and offering unmatched opportunities for the employment of improved machinery in all of the processes connected with cultivation. Even the driftless area received great benefit from the action of glaciers, for although the area was not invaded by ice, it was yet

quality of the soils in a given locality must necessarily be determin

ippi Valley have contributed something to making our soils what they are, and every later formation laid down over the surface of Iowa, or regions n

f the material so taken down into the ground decays and enriches the ground to a depth of several inches. The pocket gopher has done much to furnish a surface layer of loose, mellow, easily cultivated and highly productive soil. Like the earth worm, the gopher for century after century has been bringing up to the surface fine material, to the amount of several tons annually to the acre, avoiding necessarily the pebbles, cobbles and coarser constituents. The burrows collapse, the undermined boulders and large fragments sink downwards, rains and winds spread out th

100,000 to 170,000 years ago-somewhat prior t