LOBECK, NEW. YORK CITY. A PHYSIOGRAPHIC CENTER 



19 



studied at Delaware Water Gap (Fig. 17). At Harrisburg, Pennsylva- 

 nia (Fig. 19), the zig-zag ridges developed on pitching anticlines and 

 synclines are of classic renown, and throughout central Pennsylvania the 

 folded Appalachians provide examples of infinite variety and perfection. 

 This whole belt in Pennsylvania, Maryland, and Virginia is so replete 

 with material for the study of folded mountains that it hardly seems 

 feasible to draw any further examples in particular from it. That por- 

 tion forming the Wyoming syncline or the anthracite coal basin (Fig. 

 27) might receive especial mention as well as two or three other coal 



hoo/ey Mfn. 



RENERLANE 



A, / - 1 •*/ 1 -- 1 ^ N / _i ' -v 



The <sa//enf features of the Hackeffsfown region 



Fig. 15. — Diagrammatic representation of the essential relief features of the 

 HaeTcettstown, New Jersey, region 



The infolded, or down-dropped, belts of limestone and shale determine the position 

 of such valleys as that of the Musconetcong River (M) and German Valley next to the 

 east, while the resistent Archean crystallines still preserve the Cretaceous peneplane on 

 the New Jersey Highlands. H indicates the position of Hackettstown, just outside of 

 but within actual view of the terminal moraine. The geological column in descending 

 order is as follows : Martinsburg shale, Jacksonburg limestone, Kittatinny limestone. 

 Hardyston quartzite, Byram gneiss, all of which may be recognized in the cross-section 

 by their symbols and relationship to each other. 



basins of the east when attention is given to the economic side of the ques- 

 tion. This topic would touch also upon the extent of the Great Valley 

 from Lake Champlain along the Hudson Eiver, through Kittatinny Val- 

 ley, Lebanon Valley, Cumberland Valley, and Shenandoah Valley south- 

 ward. It would also take up the location of towns and railroads in the 

 longitudinal valleys, the character of the soil and related matters. 



Complex Mountains. — Complex mountains carved out of a foundation 

 of crystalline, metamorphic or highly contorted strata find excellent ex- 

 amples in the Adirondack Mountains, the White Mountains, the Green 



