ARTHUR WINSLOW, STATE GEOLOGIST. SHEET REPORT No. 1. A REPORT ON THE HIGGINSVILLE SHEET Lafayette County ACCOMPANIED BY A Geologic and Topographic Map and a Sheet of Sections. FROM FIELD WORK PROSECUTED DURING THE YEARS 1890 AND 1891. BY ARTHUR WINSLOW, STATE GEOLOGIST PUBLISHED BY THE GEOLOGICAL SURVEY. JEFFERSON CITY, April, 1892. PREFACE. This report, with the accompanying map and section sheet, is the first of a series of similar reports which will be issued by the Geological Survey. They will contain the results of detailed examination in the respective areas. The localities selected for such work are those which are of prominent economic importance, or which are of great geologic and scientific interest. The scope and functions of such area work have already been described in a previous publication,* and will not be farther discussed here. Suffice it to say that such work deals with all contained in a certain area, in distinction to subject work, which deals with special subjects for the whole State. The maps of these reports embody in themselves a great mass of important information, and much time and care have been given to their preparation. The map accompanying this report is termed the Higginsville sheet, is a quarter of a degree long on each side, and occupies an area of one-sixteenth of a square degree of latitude and longitude, or about 230 square miles. The scale of the map is very nearly one mile to an inch. The reasons for selecting this unit of area are that it is a fixed and permanent one, not subject to change by sub. division or otherwise, as in a county; that it can be represented on a sheet of a moderate and convenient size for reference, and that all sheets can be made of the same size and ultimately united in an atlas if desired. This same sheet unit is adopted by the U. S. Geological Survey, and the most recent maps of foreign government surveys are published on sheets of about *Biennial report of the State Geologist, transmitted by the Bureau of Geology and Mines to the 36th General Assembly, pp. 34 to 38. †The scale of the map is of nature, whereas a map on a scale of one statute mile to the inch is 360 of nature. The object in adopting the former scale is to harmonize the work with the scheme of publication of similar maps of the U S. Geological Survey, which are published on the former scale or on scales which are in simple ratio to this. the same size or less. The tendency of modern map publication is toward the adoption of a small sheet. The universal applicability of the degree, or fraction of a degree, as a unit of publication commends the plan here adopted for general use. The projection of the sheet was taken from the previously published Lexington sheet of the U. S. Geological Survey, which was based on the triangulations of the Coast and Geodetic Survey of the Missouri River Commission in this and adjacent counties: that is, the positions of the township and range lines with reference to the meridians and parallels were thus fixed. Within each cadestral township, so outlined, the section lines were located from the land office sheets, discrep ancies within such townships being distributed. The railway lines were plotted from the maps of the respective roads, and these, together with the section and other land division lines, served as lines of horizontal control. The drainage has been plotted in part from the land office sheets; at least the points of intersection of streams and section lines have been generally obtained in this way. Such locations are, however, checked by frequent intersections with the meander lines of the topographic work. Vertical control for contouring was obtained primarily from the precise leveling of the Missouri River Commission along the river, and, secondarily, from the profiles of the various railways. In addition to these, lines of level have been run by the Geological Survey through each township, thereby furnishing frequent bench-marks, and, in addition, fixing with exactness the relative elevations of coal beds and topographic features of special importance. Between these lines altitudes have been determined by aneroid barometer measurements along the lines of meander surveys. Such meander work was performed with hand compass and paced distances following along roads or along section or other land lines, and in all cases checked by frequent intersection with such lines. In these surveys the topography was sketched at the same time directly into the note-book, and all observed geological occurrences were located in their proper topographical positions. |