| In this thesis, pollen data is presented from Mission Cross Bog in the Jarbidge Mountains in northeastern Nevada. This region contains few paleoecologic sites, and this study contributes to reconstructing a more complete history of climate change in the Great Basin. The site was previously analyzed at a low resolution (one sample per 250 years). I re-cored and reanalyzed the site with the intent to do high-resolution sampling. This thesis focuses on the last 2000 years of vegetation and climate change at Mission Cross.; A 13-meter long core was recovered with a basal date of 3940 years before present. Accelerator mass spectrometry radiocarbon dates suggest a rapid sedimentation rate, 0.2–1 cm per yr. Thirty-four samples were analyzed for pollen with a sampling interval of 40 to 50 years. The results indicate at 1700 cal yr. B.P. much of the northern and central Great Basin was dry. A summer rainfall signal was apparent centered around 1200 cal yr. B.P. for much of the region, but by 800 cal yr. B.P. the northern and central Great Basin returned to drier conditions regionally. At 650 cal yr. B.P. conditions at Mission Cross Bog appear to be out of phase with the rest of the region as the climate was dry at this site but wet throughout most of central Nevada. The site appears to have remained out of phase through 550 cal yr. B.P. up until the historic period. The pollen record for the historic period appears to be largely affected by human induced environmental change, with increased shrubs on the landscape (Artemisia), and an increase in Cyperaceae on the fen, possibly in response to hydrologic changes associated with mining activity. |
