POLLEN, MACROFLORAL, AND DIATOM ANALYSIS FROM PIPE SPRING NATIONAL MONUMENT, ARIZONA

Two sediment samples collected from a black, organic layer exposed in a trench at Pipe Spring National Monument, Arizona, were examined for pollen, diatoms, and/or macrofloral remains. This layer is believed to represent an intact, natural organic stratum that formed when water ponded at the mouth of the spring. Pollen, macrofloral, and diatom analyses will be used to define environmental information and local vegetation at the time this stratum was deposited. Pollen analysis provides evidence for both local and regional plants, while macrofloral analysis focuses on identification of local plants through recovery of seeds and woody fragments. Diatoms are often useful in providing paleoenvironmental information about aquatic habitats associated with springs and spring-fed lakes and streams. With the exception of high temperature hot springs, benthic diatoms are almost always present, attached to rocks, sand and pebbles, on the surface of silt and mud, and epiphytic on the surface of submerged algae and other aquatic vegetation.