■388 E. C. AXDREWS THE HYPOTHESIS OF MOUXTAIX FORMATIOX 



today, rej^resent merely the exposed core of an ancient range or set of 

 ancient ranges whose original surfaces may well be expected to have re- 

 sembled those of the Andes, Himalayas, or western Cordillera of western 

 Xorth America. The turmoil and tumult of mountain folding passed 

 gradually from the continental nucleus to the ring including both the 

 Appalachians and the western Cordillera, but at a still later stage this 

 intensity of mountain-making had become lopsided or eccentric and had 

 passed toward the Pacific, leaving the Orient, or Atlantic, side almost 

 moribund, so far as folding phenomena were concerned. Xevertheless, 

 the two are comparable, the difference being one mainly of degree. Had 

 the Appalachians, during the closing Tertiary, been raised to heights 

 equivalent to those of the Himalaya or of the Western Cordillera, their 

 margins would have crept and have folded their own outwash gravels in 

 the process. Could the core of the mighty plateau of the Himalaya be 

 exposed to view today, doubtless it would be seen that the surface, with 

 its faulted and warped margins, passes downward into zones of rock 

 foldino- and llowao-e of the same a^-e as the pleateau surface. 

 Of the Tian Shan. Davis- says that the — 



^'contrast between the earlier Tian Shan system and the present ranges is 

 ^imihir to that pointed out by Gilbert between the Appalachians and the Basin 

 Hanges of Vtah and Nevada."' 



In this connection the remarks of Ellsworth Huntinston^ concernins: 

 the Tian Shan during the Cenozoic are worthy of the utmost consider- 

 ation : 



"Coupled with the uplifting of the peneplain by which it was deformed into 

 basins large and small, with intervening swells or ridges, as far as was ob- 

 .served. this warping does not seem to have initiated new lines of stress, but 

 to have conformed to old ones of Tertiary age. In the old movements faulting 

 takes place abundantly : in the new movements warping was the rule and 

 faulting took place rarely. The Quaternary basins seem to be revivals of 

 former basins. . . . The scale of the Quaternary warping was large, for 

 some of the ridges, such as the main crests of the Tian Shan Plateau and of 

 the Alai Range were raised over lO.O^K) feet above the bottoms of the neighbor- 

 ing basins." 



"Apparently, the Kashgar Basin has long been growing smaller by a process 

 of continuous folding along the edges, and as it has grown smaller the locus 

 of deposition of the gravels which accumulated along its edge has gradually 

 been pushed inwards'" (p. 170). 



"Along the section"' the profile is essentially a very broad anticline of the 



* Explorations in Turkestan. Pumpelly Expedition. Carnegie Inst., 1905. p. SI. 

 ^ Explorations in Turkestan, rumpelly Expedition. 190.3. 

 I'^Tian Shan (.E. C. A.j. 



