COMBINING ORGANIC PETROGRAPHY, PALYNOMORPH ASSEMBLAGES AND LITHOLOGIC OBSERVATIONS TO RECONSTRUCT THE PALEOENVIRONMENT OF THE COOS BAY BASIN, SOUTHWEST OREGON, USA
Results from organic petrography analysis indicate that all 40 samples are type III kerogen, and are rich in the humodetrinite maceral, with minor, variable amounts of liptodetrinite and sporonite macerals. This suggests that the majority of sediments from the eight rock units were deposited proximal to the terrestrial paleoshoreline, with influxes of strong to weak marine influences. Based on the palynomorph assemblages, the Middle Coaledo, Lower Coaledo and the Beds of Sacchi Beach formation contain an abundant, diverse assemblage of Eocene dinoflagellates, and therefore exhibit the strongest marine influence out of the eight formations. Lithologic interpretations for the Lower Coaledo suggest a distributary fed shelf with lower shoreface to distal prodelta depositional environments, as suggested by the palynomorph assemblages. For this research, we present the integration of various data and possible depositional models.