National Geographic : 1894 May 23
80 Hayes and Campbell-Appalachian Geomorphology. In order to represent in as graphic a manner as possible the present form of this Cretaceous peneplain a contoured map of the deformed surface has been constructed. Upon this map are assembled all available data derived from a careful comparison of the various known remnants of the plain within the province. The result appears as plate 5, and although regarded by the writers as preliminary, it embodies all the information at present attainable. Although imperfect, the map is highly suggestive, and it is hoped that it may lead to the construction of similar maps of other regions in which equally important results would undoubtedly be obtained. Different portions of the map repre sent widely different proportions of fact and hypothesis, and hence differ in value. Thus in the southern part of the province the peneplain, as already described, is well preserved; also the map of this portion is based upon a large number of personal observations and may be considered fairly accurate. In some regions in the northern portion of the province only scanty re mains of the peneplain can be found, and the evidence of its existence is so indefinite that while the present map is unsatis factory it is doubtful if anything better can be constructed even with fuller field observations. Other portions are based upon a study of imperfect topographic maps or railroad profiles and verbal descriptions of topography, so that the results are corre spondingly unsatisfactory. As already indicated, the deformations of the Cretaceous pene plain represented by the contour map (plate 5) are not the result of a single elevation or a single system of orogenic movements, but the algebraic sum of'all movements both of elevation and depression which have affected the region since the peneplain was formed. Not only have the movements been in opposite directions and at different periods, but the axes of maximum motion have not always been the same nor even parallel; they have intersected at various angles, and the surface has been warped accordingly. The data are not sufficient for mapping all the details and a description of the principal axes only will be attempted. LongitudinalAxes of Elevation.-Thereare three principal longi tudinal axes, and so far as known, these are axes of elevation alone, though depression of which no record is left may have taken place along them also. They are indicated by broken lineson plate5 and marked by theletters CD,EFand GH.
1894 Jun 22
1894 Apr 25