Sand and gravel on the continental shelf off the northeastern United States

Circular ◽  
1968 ◽  
Author(s):  
John Stevens Schlee
Keyword(s):  
United States ◽  
Continental Shelf ◽  
Northeastern United States ◽  
Sand And Gravel

Pseudo-Ice-Wedge Casts of Connecticut, Northeastern United States

1983 ◽  
Vol 20 (1) ◽  
pp. 74-89 ◽  
Author(s):  
Robert F. Black
Keyword(s):  
United States ◽  
Water Table ◽  
Physical Environment ◽  
Northeastern United States ◽  
Complex Fracture ◽  
Ice Wedge ◽  
Sand And Gravel ◽  
Coated Sand ◽  
Horizontal Layers

AbstractSince 1965, ice-wedge casts have been reported in deposits of sand and gravel in Connecticut. These are wedge forms up to 1.1 m wide and many meters high. Most are single forms, not in polygonal array. They are found in adjoining states as well. Their distribution, dimensions, structure, and fabric and an assessment of the former physical environment preclude their origin as permafrost features. They appear to be tension fractures produced by the loading of coarse clastics on fine clastics near and below the water table where sediments creep toward a stream or depression. Locally movement started with kettle formation during deglaciation. However, some wedges cut horizontal layers of iron-coated sand and gravel and must be younger than those distinctly postglacial phenomena. Moreover, modern B horizons of the overlying soil have moved down into some wedges more than 2 m, indicating that fracturing is still active today. Complex fracture fillings in bedrock also have been attributed to a permafrost origin, but this too seems unlikely.

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