Figure 58. Composite stratigraphic column for Ojo Alamo type area showing relative stratigraphic levels of samples collected for biochronologic and 40Ar/39Ar sanidine-crystal dating from Ojo Alamo Sandstone and uppermost Kirtland Formation. Samples from different localities are projected into one column for ease of portrayal, however, localities are dispersed throughout Ojo Alamo type area as shown on Figure 4 and Figure 51.