Arthur Winslow
Published: 2015-06-30
Total Pages: 26
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Excerpt from The Geology and Mineral Products of Missouri The State of Missouri is located in the central portion of the United States, in that region known as the Mississippi valley. It is bounded on the east by the Mississippi river, on the south by the lines 36 and 30 30 of north latitude, and on the west by the meridian which passes through the mouth of the Kansas river at latitude 39 7', and longitude 94 37'. Thence the boundary line follows the Missouri river in a northwesterly direction to a point at about latitude 40 34 2/3', longitude 95 . This is the northwestern corner of the State, and thence the northern boundary line extends eastwards approximately along the line of same latitude to the Des Moines river, which it intersects at longitude 91-1, about 25 miles above the mouth of that stream. The area of the State, according to the figures of the eleventh census of the United States, is 69,415 square miles. Physiography. Generally speaking, the whole State is an incised plain; no great mountain ranges traverse it. The maximum difference of absolute elevation within the whole area is only 1,500 feet; the local and relative differences are still less, and do not exceed 700 feet. More closely speaking, the following four topographic divisions may be recognized: (1.) A plain or prairie country. (2.) A plateau country. (3.) A highland or semi-mountainous country. (4.) An alluvial or swamp country. (1.) The Prairie Country. - The prairie country of the State is principally represented in the northern portion, and in that part north of the Missouri river; it also occupies, however, nearly all of the two tiers of counties south of that stream which extend along the Kansas line. Adjacent to the Missouri river and to other large streams this country loses its prairie features and is rugged and characterized by steep, timbered slopes and bluffs adjacent to and bordering the flood plains of these streams. Away from the channels, however, the country assumes the character of a broad plain, sometimes flat, but generally undulating. In fact the local differences of elevation often amount to 100 feet or more, but the slopes are so gentle that the country does not lose the aspect of a plain. The growth of trees is here not abundant, excepting along the streams. It must, however, be understood that, though a comparatively level and treeless country, it is of a very different type from the great flat plains of Western Kansas. (2.) The Plateau Country. - The plateau country of the State occupies the central southern part, south of the Missouri river. This is the area known as the Ozark Mountains, and is essentially a dome-shaped uplift, with very gentle quaquaversal slopes. It differs from the prairie country chiefly in its greater relative altitude, and in that it is not covered by a protecting and modifying coat of glacial material. As a result the land is more pronouncedly sculptured. The valleys are cut deeper, and the slopes are more abrupt; the area is made up of a series of long ridges and hills, divided by deep narrow valleys, often oi carbon-like dimensions. Timber is abundant, but, on the other hand, the land is generally less fertile than that of the northern portion of the State. Near the crest of the Ozarks the type of topography is not nearly so pronounced, and we have here quite a large expanse of undulating country; thence, in all directions, however, the streams cut deeper and deeper, and the profile becomes more serrated. (3.) The Highland Country. - What we term for convenience the highland or semi-mountainous country, lies in Southeastern Missouri, and includes what we have named the St. Francois mountains. These are a series of knobs and domes of Archean porphyry and granite which rise to altitudes of from 1,700 to 1,800 feet, A.T., and some 700 feet above the surrounding valleys. The whole area covered by these mountains is not over 1,000 square miles. These are d."