NEW YORK 417 



763. Niagara escarpment without capping of Niagara limestone; looking west 



from a point near Middleport, New York (No. 1750). 



764. Drowned valley of Twelve-mile creek, near Wilson, Niagara county, New 



York. Water lilies grow on submerged alluvial plain (No. 1760). 



765. Head of estuary of Twelve-mile creek, Niagara county, New York. Sub- 



merged alluvial plain supports rushes (No. 1761). 



766. Estuary of Eighteen-mile creek, near Olcott, Niagara county, New York. 



Channel deep, current slow. Submerged alluvial plain supports rushes. 

 (No. 1762). 



767. Valley of Eighteen-mile creek, Niagara county, above head of estuary. 



Channel shallow, current rapid ; alluvial plain dry except during flood 

 (No. 1763). 



768. Post-Glacial anticline, Hopkins creek, Niagara county, New York. The dis- 



placement of the rocks is accompanied by a superficial ridge traversing an 

 alluvial terrace (No. 1761). 

 761). Section of Niagara limestone, Cooks quarry, near La Salle, Niagara county, 

 New York. Shows structure described b} r James Hall, Geology of Fourth 

 District of New York, pages 93 and 94 (No. 1765). 



770. Section in cut of Erie railway, Niagara falls, New York. Shows structure 



described by James Hall, Geology of Fourth District of New York, pages 

 93 and 94 (No. 1766). 



771. Weathering of Niagara limestone by solution. A joint face exposed in quar- 



rying southwest of Middleport, New York (No. 1767). 



772. Weathering of Niagara limestone by solution; old quarry southwest of Mid- 



dleport (No. 1768). 



773. Unconformity by erosion. Sandstones and shales of the Medina formation, 



Niagara gorge (No. 1769). 



774. Isolated limestone mass at base of Niagara shale, containing "transition 



fauna" of Ringueberg (No. 1770). 



775. Section of ripple-mark on Medina sandstone, Lockport, New York. From 



crest to crest, 23 feet; depth of trough, 29 inches (No. 1771). 



776. Flagstone in court-house yard, Elyria, Ohio. Shows reticulated ripple- 



marks (No. 1772), 



777. Trough of large ripple-mark in Medina sandstone, Niagara gorge, New York 



(No. 1773). 



778. Crest of large ripple-mark in Medina sandstone. Quarry near Lewiston, 



New York (No. 1774). 



779. Crest of large ripple-mark in Medina sandstone. Quarry in Lockport, New 



York (No. 1775). 



780. Diverse cross-bedding associated with large ripple-marks in Medina sand- 



stone. Quarry near Lewiston, New York (No. 1776). 



781. Quarry face in Medina sandstone, Lockport, New York (No. 1777). 



782. Quarry face in Niagara limestone, Lockport, New York. The joint face 



shows weather fracture (No. 1778). 



783. Shore of lake Ontario at Wilson, New York. Train of shore drift from right, 



being arrested by bew-pin, begins to accumulate and partly protects bluff 

 from wave attack. Dearth of shore drift under lee of pier favors wave 

 attack ; bluff' eaten back 45 feet, Bluff contains two tills and cover of lam- 

 inated clay, a deposit from lake Iroquois. Boulder pavement at top of 

 lower till, indicated by arrow (No. 1779). 



