Iowa Geological Survey, Volume 13Published for the Iowa Geological Survey, 1903 - Geology |
Common terms and phrases
1/4 of section Acervularia Albion township Atrypa beds blue clay bluffs bottom Buchanan gravels Butlerville calcareous calcite Cedar river chert Chickasaw county Coal Measures color corner of section creek crinoid dark deposits depth Devonian diameter dolomite drainage east erosion exposed exposures feet fine-grained Florenceville fossils fragments FREMONT COUNTY Fusulina Geol geological glacial hills horizon Howard county inches indurated rocks Iowa river Iowan ice Iowan plain Kansan drift Kinderhook Kossuth Kossuth county layers ledges lime Lime creek limestone Little Cedar loess Loess-Kansan magnesian Maquoketa material matrix miles Mitchell county Moines moraine northeast northwest occurs oölite Osage outcrops overlying pebbles places Pleistocene portion prairie preglacial Productella Productus quarry quarter of section region sand sandstone seams seen shale shaly sheet side slopes soil southeast southwest species Spirifer streams stromatoporoids surface Tama county thickness thin tion topography tree upland upper valley Vernon Springs yellow zone
Popular passages
Page 316 - ... ranging from a fraction of an inch to more than a foot in diameter, are now standing at every possible angle (Fig. 50). In some cases a certain amount of continuity may be traced from fragment to fragment of the same bed, the pieces showing very clearly that they are the constituent parts of a collapsed arch, but in general the displaced and FJo.
Page 53 - Devonian appearing in some places qiuite conspicuously above the Maquoketa, well up on the steep hillsides. It is the Productella beds that are seen at the level of the water below the mill, at the old town of Lime Springs. Above this point the dip of these beds soon carries them below the level of the stream. 2, The member of the Devonian series which follows the Productella beds in Howard county is the equivalent of the Acervularia davidsoni beds of Buchanan county. It is made up of a succession...
Page 46 - One very important matter in testing of this order of delicacy is the cleaning and washing out of the apparatus, and it should be borne in mind that all glass surfaces which have been exposed to the air for any length of time are liable to contract traces of ammonia from the air ; and the rule which has to be observed, in order to ensure accuracy, is to wash out with clean water immediately before use. Furthermore, it may be remarked that for these washings it is unnecessary to employ distilled water;...
Page 401 - ... two separate outlets, separated by natural strata of not less than one hundred feet in breadth, by which shafts or outlets distinct means of ingress and egress are always available to the persons employed in the mine ; but...
Page 260 - He must think himself fortunate if he can reach, at night, a few scattered oaks to plenish his fire, and boil his camp kettle ; and he may consider it a special instance of good luck, if, in return, he can catch a glimpse of a rock exposure once or twice a day.
Page 194 - The drift is of the typical lowan character. It is yellowish brown in color. The iron which it contains is not fully oxidized and the calcareous matter is not leached from the surface. It carries but few pebbles or small bowlders as compared with the Kansan and of these there is but a small percentage of the dark colored trap or greenstones.
Page 418 - Two fairly distinct types may be recognized; the modified loess-Kansan of the upland and the alluvial of the bottom and "second bottom" lands. The first covers much the greater area, while the latter is the more tractable and may be the more productive. Near the divides the clay constituent may be so great in the loess-Kansan as to render it mucky and imperfectly drained. In such instances the land is cold when wet and tends to bake when it dries, qualities not favorable to the growth of cereals....
Page 37 - sloughs," in place of eroded creek beds, serve to collect the waters from the adjacent slopes. While the drainage courses seem to have been determined by the position of preglacial valleys, the streams of the southwestern part of Howard county have accomplished very little in the way of erosion. They have neither valleys nor flooded plains in the ordinary sense. They run in simple shallow trenches cut only a few feet below the level of the surface on which they began to flow after the withdrawal...
Page 197 - ... materials that is found over its surface. The cause or causes which resulted in the early cessation of the flow of ice over this lobe did not produce their full effect at once. The movement probably ceased quite suddenly over the southern half of the area, but its withdrawal from the northern...
Page 84 - We have plains wide extended, so level that for the passing traveler no inequality can be perceived ; towns may hail towns across the unbroken fields and houses dot the distant landscapes like blocks upon a sheet of cardboard. We have precipitous hills rising like miniature mountains directly out of the plain, some of them in groups two or three hundred feet high enclosing lakes, like mountain lakes far above the general level, mantled in native forest and looming blue along the prairie horizon visible...