Preliminary assessment of the age of the palynoflora of the Red Tanks Member, Madera Formation, Carrizo Arroyo, New Mexico
— Alfred Traverse and Sidney R. Ash

Multiple palynological analyses of two shale samples of Red Tanks Member, Madera Formation, from Carrizo Arroyo, Valencia County, NM, show that the samples represent levels near the Pennsylvanian/Permian system boundary. Sample AR1-8 was deposited rapidly from brackish nearshore water, under conditions favoring anoxic sulfur bacteria and pyritization of the monosaccate-dominated palynoflora, which is Late Pennsylvanian in age. Sample AR 1-8 , about 30 m higher stratigraphically, was deposited rapidly in a deltaic channel or other freshwater environment from which oxygen was excluded. The abundant, well preserved palynoflora is dominated by bisaccate pollen, including forms such as Platysaccus spp. and Limitisporites sp., indicating an Early Permian age. Sample AR 1-1 is probably the closest palynologically to the Pennsylvanian/Permian system boundary of any flora yet described from the southwestern USA.