LIST OF ILLUSTRATIONS 



PAGE 



Figure 1 (Frontispiece) Rensselaerville Falls, Albany county, 



N. Y. Upper Devonian section: Oneonta red beds. 12 

 Figure 2 Cross section illustrating pinching or lensing out of 



strata 42 



Figure 3 Delta structure 43 



Figure 4 Marine transgressive and regressive overlap 45 



Figure 5 Alluvial cone transgressive overlap 46 



Figure 6 Outcrop of rock illustrating strike and dip 49 



Figure 7 Diagram illustrating homemade clinometer with 



needle attached as a pointer 50 



Figure 8 Folds 52 



Figure 9 Faults 55 



Figure 10 Unconformities 57 



Figure 1 1 Dike, sill, laccolith, batholith 64 



Figure 12 Diagram showing the marine realms (modified after 



Lull) 78 



Figure 13 Exposed rocks at East Point, Nahant, Mass 119 



Figure 14 An abundance of the periwinkle Littorina litorea and 

 the barnacle Balanus on a rock where boulders are 



present, Nahant, Mass 119 



Figure 15 The seaweed Fucus replaced by the sea mussel 

 Mytilus on a rock face exposed to wave action, 



Nahant, Mass 132 



Figure 16 Alga-covered rock face, Nahant, Mass 132 



Figure 17 The barnacle Balanus on a vertical rock wall \ 135 



Figure 18 The periwinkle Littorina in a crevice just above the 



Ascophyllum zone 135 



Figure 19 The Wharf -Pile group in the American Museum of 

 Natural History. Designed and supervised by 



R. W. Miner 173 



Figure 20 Geologic map of New York state 188 



Figure 21 Northeast-southwest section across New York state. 

 From Elmira across the Upper Mohawk valley and 



the Adirondacks to Rouses Point 188 



Figure 22 Precambrian and Cambrian (lower and middle) out- 

 crops 205 



Figure 23 Lower Cambrian rocks, Nassau beds (slate and 

 quartzite) between Brainard and Nassau, Rens- 

 selaer county 235 



Figure 24 Lower Cambrian rocks. " Edgewise " breccia in 

 Schodack shales and limestones, near Snyder's 



lake, Rensselaer county 236 



Figure 25 Lower Ozarkian outcrops 238 



Figure 26 Lower Ozarkian rocks. Potsdam sandstone, Ausable 



Chasm, Essex county 240 



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