CONODONT BIOSTRATIGRAPHY OF THE LOWER SILURIAN MAPLEWOOD FORMATION, WESTERN NEW YORK STATE

Conodonts from the basal Densmore Creek Phosphate Bed of the Maplewood Formation in Irondequoit, NY include Ozarkodina oldhamensis?, Panderodus unicostatus, Pranognathus tenuis, and all of the elements of the Icriodella discreta apparatus. Ozarkodina oldhamensis, Panderodus unicostatus, Pranognathus tenuis, and Icriodella sp. were recorded from the overlying Budd Road Phosphate Bed in Lockport, NY. The specimens from both beds are indicative of the Pranognathus tenuis zone, giving the Maplewood Formation a middle Aeronian age of approximately 439.21 to 440.77 Ma. The relative abundances of the species found in each locality indicate that the Budd Road Phosphate Bed was deposited under deeper conditions than the Densmore Creek Phosphate Bed. There is no conodont evidence for a significant unconformity between the Maplewood Formation and the Budd Road Phosphate Bed, as proposed by LoDuca and Brett (1994).