58 W J MCGEE — UNIFORMITARIANISM AND DEFORMATION. 



lines were once horizontal, but now they are warped in such manner as 

 to demonstrate differential vertical movement of the earthcrust. The 

 differential movement recorded in the warped beaches amounts to scores 

 of yards; yet there is no shadow of record of any horizontal movement 

 connected therewith. The region of the Great lakes is similarly traversed 

 by terraces and strands marking several stages in the development and 

 destruction of interior lakes and ocean-connected bays. From these 

 shore-marks an elaborate history of the later episodes of the Pleistocene, 

 of the melting of ice and the birth of rivers, of the formation of lakes and 

 the draining of basins, has been read ; yet no part of the record is of 

 greater interest than that which tells of the warping of the earthcrust as 

 the ice retreated. This warping reached scores, and in some cases hun- 

 dreds, of feet ; but so far as known it was entirely vertical, and there is 

 nothing to attest and everything to disprove horizontal movement of 

 appreciable amount. 



These instances of earth-warping recorded in ancient beaches and ter- 

 races might be multiplied indefinitely, and all are consistent and point 

 in the same direction — all tell of vertical movement, none tell of hori- 

 zontal movement. The inferences by which the record is interpreted are 

 direct. The wave-work inferred is like the wave-work observed, and the 

 oscillation inferred is in no way different from the oscillation observed. 

 So the testimony of the ancient beaches is in harmony with the observa- 

 tions of laymen and surveyors, and attests corporeal movement in the 

 earthcrust which is chiefly or wholly vertical, only subordinately if at 

 all horizontal. 



MOVEMEjyrS INFERRED FROM LATER FORMATIONS AND UNCONFORMITIES. 



The coastal plain of southeastern United States is built of a succession 

 of formations, each commonly separated from its neighbors b}^ uncon- 

 formities, and under the consistent interpretation of all students the 

 formations are records of submergence beneath oceanic waters, the un- 

 conformities records of emergence above tide and of sculpture b}^ rain 

 and rivers. The latest record of the past is one of higher level than the 

 present, when the rivers cut channels that are now partl}^ drowned by 

 the encroaching Atlantic ; and there are indications that the subsequent 

 sinking of the land was not everywhere the same, but that the earth- 

 crust warped in some measure. The recent subsidence reaches scores or 

 even hundreds of feet, yet there is no measurable record of concurrent 

 horizontal movement. The next earlier episode recorded by the deposits 

 and unconformities of the coastal plain is one of submergence, during 

 which the Columbia formation (or the earlier portion of that deposit, if 

 it be divided) was laid down. This submergence varied in different 



