ILLUSTRATIONS Vll 



Grabau : Pa S e 



Figure 1 — Sagging and truncation of Manlius limestone 356 



" 2 — Channeling of Manlius limestone 356 



" 3 — Channeling of Manlius limestone 356 



" 4 — Erosion of Manlius limestone 356 



" 5 — Excavation of Manlius limestone 357 



" 6— Fragment of rock from margin of sandstone dike 358 



Figures 7 and 8 — Sand grains from dike enveloped in secondary quartz. 359 



Washington : 



Figure 1 — Chemical relations and serial character of Magnet Cove rocks. 404 

 Willis : 



Figure 1 — Generalized section of Santa Lucia range and San Antonio 



valley 421 



" 2 — Diagrammatic summary of orogenic movements for the dis- 

 trict of the northern Santa Lucia range from Paleozoic time 

 to the present 431 



Woodworth : 



Figure 1 — Geologic map of the vicinity of Plainville, Massachusetts. . . 451 



" 2 — Batrachiclinus plainvillensis sp. nov 452 



Hopkins: 



Figure 1 — Cross-section of ore nodule from Cambrian slates 478 



" 2 — Section at Pennsylvania Furnace ore bank 485 



" 3 — Ideal section illustrating possible mode of accumulating iron 

 ore underneath the clay by process of segregation and 



leaching 486 



" 4 — Cross-section of ore bank at Hensingerville, Pennsylvania. . . 487 

 " 5 — Map of South Mountain region, Cumberland county, Penn- 

 sylvania 488 



" 6 — Map of portion of Great Valley region, western part of 



Lehigh county, Pennsylvania 490 



" 7 — Cross-section of anticline in Nittany valley, Pennsylvania. . . 493 



(58 plates ; 37 figures. ) 



