690 



DYNAMICAL GEOLOGY. 



is intersected by fractures or crevasses, made by its movement through 

 the irregular valley. 



Glaciers descend slopes of all angles ; and, as with water or pitch. 



Figs. 1100-1104. 



Fig. 1100. — Part of the glacier-district of Mt. Blanc, the lighter middle portion of the map six 

 teen miles long, out of twenty-two miles the whole length ; river on the northwest side, the Arve 

 in the valley of Chamouni, and that on the southeast Mde, the Doire ; B, Mt. Blanc; 6, Aiguille 

 an Geant ; J, the Jardin ; T. Aig. du Tour ; V, Aig. Verte : a, Argentiere Glacier ; ba, Brenva 

 61. ; bn, Bossons Gl. ; bs, Bois Gl ; g, Geant or Tacul Gl. ; /, Lechaud Gl. ; m, Mer de Glace, up- 

 per part of the Bois Gl. ; mg, Miage Gl. ; ta, Talefre Gl. ; tr, Tour Gl. ; tt, Trient Gl. 



Fig. 1101. —Section of the Mer de Glace, near m of Fig. 1100, or opposite Trelaporte; 1102, sec- 

 tion of same, near bs of Fig. 1100, or opposite Montauvert ; 1103, View of the Rhocte Glacier ; 1104, 

 profile of same, c, c, etc., being the transverse crevasses, fading out, and becoming curved after 

 passing the cascade at m «. 



