Along
the steep cliff at the western edge of New York State, Ripley Beach on the Lake
Erie shoreline contains an outcropping of Canadaway Group lithologies which
provide insight to the depositional environment of the Early Famennian of the
Upper Devonian. The outcrop at Ripley Beach shows portions of the Gowanda
Member and the Laona Member of the Canadaway Group. The Gowanda Member is
dominated by fine grained shales, but interbeds of silt and sand within the
Gowanda Member exhibit hummocky cross stratification and some beds contain sole
structures such as groove casts and hypicnial burrows which all are present in
tempestite deposits. The alternation between fine grained planar stratification
and hummocky cross stratification in coarser grained material points to a
depositional environment on a shallow marine shelf battered by frequent storms.
The Laona Member is representative of a larger accumulation of tempestite
deposits on this shelf, with fine sand and silt as the dominant deposited
grains, whereas the Gowanda Member represents a period on the shelf where
storms were less frequent, and muds and clays were deposited along this shallow
marine shelf.
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