Three palynological assemblage zones, based on two major floral changes, are established within the upper Lance (Late Cretaceous) and Fort Union (Paleocene) Formations in and adjacent to the type Lance area in southeastern Wyoming. The lower palynological change essentially coincides with the Cretaceous-Paleocene (Maestrichtian-Danian) boundary, which is based on the vertebrate, fossil leaf, and foraminiferal evidence of previous workers. The upper palynological change occurs in the lower part of the Lebo Shale Member of the Fort Union Formation. The oldest palynological assemblage (Assemblage A) is of Maestrichtian age and is characterized by diverse and abundant angiosperm pollen, particularly species of the genera Gunnera, Proteacidites, Aquilapollenites, and Cranwellia. The middle assemblage (Assemblage B) is, in part, of Danian age and is composed mostly of fern and moss spores and small tricolpate and tricolporate angiosperm pollen. The youngest assemblage (Assemblage C) is of Paleocene age and consists primarily of taxodiaceous-cupressaceous pollen with secondary but significant quantities of betulaceous and juglandaceous pollen. These defined floral assemblages occur regionally and are considered to be synchronous. The Assemblage A-Assemblage B boundary coincides with the Hell Creek (Lance) -Fort Union contact in the Cave Hills area of South Dakota (Stanley, 1965; this study), in the type area of the Hell Creek Formation in Montana (Norton, 1963; Tschudy, 1968, oral commun.), and in the type area of the Cannonball Member of the Fort Union Formation in North Dakota. The Assemblage B-Assemblage C boundary occurs in the lower part of the Tongue River Member of the Fort Union Formation in the type Cannonball area and in the lower Fort Union Formation in central and western Wyoming. Occurrences of Assemblage B in the lower Tongue River Member in the Cave Hills and type Cannonball areas of northwestern South Dakota and central North Dakota indicate that the lower Tongue River in these areas is older than the lower Tongue River in the Powder River Basin of Wyoming. Two new genera, Maceopolipollenites and Insulapollenites, and sixteen new species have been described, and the generic description of Kurtzipites has been emended.

Palynological analyses of microfossil assemblages from Upper Cretaceous and lower Tertiary rocks in British Columbia and adjacent Alberta indicate major differences in the evolution of floras between coastal and interior locales. The Santonian-Campanian assemblage on the coast is dominated by an assemblage of ferns, herbaceous angiosperms, and Proteacidites, whereas the assemblage from beds of similar age in western Alberta is typified by different species of ferns, probable herbaceous angiosperms, and Aquilapollenites. These differences suggest the existence of two floral provinces during Santonian-Campanian time, possibly separated by the western cordillera. A late Maestrichtian-Danian assemblage from the Rocky Mountain trench contains a taxodiaceous-angiosperm complex that differs from an assemblage of essentially the same age in the western interior region (eastern Montana-western South Dakota) of the United States, suggesting again the presence of two different floral provinces at this time. A comparison of middle Eocene assemblages on the coast with those of the interior plateau regions of southern and central British Columbia shows a coastal assemblage composed of ferns and mainly herbaceous angiosperms, whereas the comparable assemblage east of the Coast and Cascade Mountains contains a predominantly coniferous-hardwood flora.

ABSTRACT Campanian, Maestrichtian, and Danian strata of the northern San Joaquin portion of the Great Valley forearc basin form a complex assemblage of varied siliciclastic lithofacies derived from the Mesozoic Sierran magmatic arc to the east. Along the eastern margin of the basin, two major deltaic complexes prograded southwestward into the deeper parts of the basin and record final filling of the basin to sea level. The older deltaic complex, the Starkey Formation, is of middle Campanian to middle Maestrichtian age, reaches almost 3,000 feet thick, restricted to the subsurface, and consists of four principal stacked progradational wave-dominated deltas separated by transgressive shale intervals. The younger deltaic complex, the Garzas Formation, is of middle Maestrichtian to Danian age, is as thick as 1,750 feet, is present as a progradational sequence over the entire basin and crops out along the western flank of the basin, and is truncated by a regional post-Danian unconformity.

Abstract A biostratigraphic, chronostratigraphic, and magnetostratigraphic model has been calibrated to produce a new time scale for the Paleogene. The model gives the biostratigraphic position and duration represented by significant unconformities in three areas of the Atlantic and Gulf Coastal Province: 1) western and central Alabama; 2) South Carolina; and 3) central Virginia to southwestern Maryland. In these areas, the most significant unconformity, in terms of duration represented and lateral extent, is found in the lower Eocene. In Alabama, this unconformity centers around 51.4 m.y. and represents a hiatus of about 1.4 m.y. In South Carolina, this unconformity centers around 50.3 m.y. and represents a hiatus of about 10.0 m.y. In Virginia-Maryland, the lower Eocene unconformity centers around 49.0 m.y. and represents a hiatus of about 7.3 m.y. A significant unconformity exists between the Cretaceous and Tertiary in all three areas. On the Atlantic coast the Cretaceous-Tertiary unconformity represents some missing Danian and significant missing Maestrichtian. In Alabama, however, there is virtually a complete Danian section and it is only most of the upper Maestrichtian that is missing. There are significant regional unconformities in all three areas.