June U, 1907] 



SCIENCE 



947. 



topography appears to have heen carved out of 

 an ancient highland, as is indicated by the 

 striking -uniformity of the summit altitudes, 

 which range from about Y,500 feet in British 

 Columbia to about 5,000 feet in Alaska. Here 

 and there pyramidal peaks rise above the 

 general sky line, as if representing the fast- 

 disappearing remnants of eminences not re- 

 duced to the general regional level in an 

 earlier cycle of erosion. The Endicott range, 

 the most important member of the Eocky 

 mountain province in Alaska, appears to have 

 had a similar history. When viewed from 

 altitudes of 6,000 feet, the summits ' show a 

 remarkably even sky-line and strongly sug- 

 gest that they have been carved from a former 

 plateau.' Here, while the transverse valleys 

 are sharply cut, the longitudinal valleys are 

 broad with gentle slopes. The Central 

 plateau, between the Endicott and the Pacific 

 ranges, is described as a gently rolling upland 

 in which the rivers have trenched broad val- 

 leys; occasional mountains or mountain 

 groups break the continuity of the plateau. 

 All these provinces appear to have been eroded 

 to moderate relief during a lower stand of 

 the land; the contrasts that they now present 

 seem to be due in part to difference in the 

 amount of uplift, and in part to difference 

 in the depth and stage of revived erosion. 

 Although the ranges here considered do not 

 possess even-topped summits, such as occur in 

 certain other mountain ranges lately referred 

 to in these notes, they appear with many 

 others to confirm the law to which Powell gave 

 Bo much emphasis : that plateaiis of uplift are 

 fashioned into mountains by rivers and 

 glaciers. 



I. B. 



THE WOLDS AND VALES OF BELTED COASTAL 

 PLAINS 



The development of longitudinal belts of 

 higher and lower ground in a coastal plain 

 (or other similar structure) that initially pos- 

 sessed a single continuous transverse slope 

 toward the sea, is a question to which sys- 

 tematic attention has been given but recently 

 in books on physical geography. A termi- 

 nology appropriate for the description of 



longitudinal relief of this kind has lately 

 been suggested by A. C. Veatch in connection 

 with the examples that occur in New Jersey 

 and Long Island (' Underground Water Re- 

 sources of Long Island, N. T.,' prof, paper 

 44, U. S. Geol. Survey, 1906, 28-32). He in- 

 troduces the English terms, wold and valej 

 wold, for the upland which is sustained on a 

 belt of more resistant strata; and vale, for 

 the longitudinal depression that is excavated, 

 chiefly by subsequent streams, on a belt of 

 weaker strata. Thus he calls the inner low- 

 land in New Jersey the Hightstown vale; and 

 the enclosing upland the Perrineville wold; 

 the former having its northeastward extension 

 submerged in Long Island Sound; and the 

 latter forming the body of Long Island itself, 

 now ornamented with glacial additions. In 

 this connection, an ingenious explanation is 

 offered for the deflection of the Delaware, 

 Susquehanna and Potomac rivers for short dis- 

 stances southwestward along the vale, before 

 they transect the wold: Direct consequent 

 courses are assumed to have prevailed in the 

 first cycle of coastal-plain erosion (in which 

 the small relief of old age was presumably 

 attained) ; then during a time of depression, 

 the transverse passages through the wold were 

 obstructed by Lafayette deposits; and on 

 reelevation — ^probably with a slight tilt to the 

 southwest — the three rivers deserted their 

 former transverse notches and sought new 

 ones. The problem is necessarily an obscure 

 one, because of the large amount of erosion 

 since the deflected courses were taken. Dar- 

 ton (and later, Newsom) had previously ex- 

 plained these eases of river deflection as 

 caused by coastal sand reefs during a time of 

 submergence; but Veatch points out that this 

 would not account for the occurrence of de- 

 flection only in those rivers where a vale had 

 been eroded on weak Cretaceous beds. 



In my own practise, the forms here 

 designated by wold and vale have been called 

 cuesta and (inner) lowland. Objection has 

 been frequently urged against the Spanish 

 word, cuesta, because it does not mean only a 

 lop-sided ridge, but a hill or slope of any kind. 

 To this my answer has been that, as soon as 

 any other fitting term comes to be generally 



