SEDIMENTOLOGY

     
RIPPLE MARKS    
 
MODERN RIPPLES:

Ripples formed in sand along a beach. (Sandy Hook, NJ)

  ANCIENT RIPPLES:

Ripple marks in sandstone exposed on the bedding surface of the rock layer. (Pennsylvania)

ENVIRONMENTAL INTERPRETATION: Ripples develop when sediment is carried by a moving current (water or wind).
     
MUDCRACKS    
   
    Polygonal shaped cracks on this bedding surface are related to the cracking that occurs when the original muddy sediment dries and shrinks.