TEMPORAL AND SPATIAL VARIABILITY OF HIGH RESOLUTION POST-LAST GLACIAL MAXIMUM (LGM) CLIMATE RECORDS, SOUTHERN SAN JUAN MOUNTAINS, COLORADO

Terrestrial paleoclimate records are commonly derived from alpine/sup alpine bog and lake cores. Although duplicate records are commonly described in a single bog or lake; it is rare for duplicate records to be compared between bogs located within the same region. We are examining cores with contrasting geomorphological and microclimatological characteristics to determine to what extent their paleoclimate records are representative of regional climate verses the microenvironment of the bog itself. Three cores were extracted from filled kettle ponds located within ~35 km of each other in the Conejos River region of southern Colorado. Core 1 is from an exposed bench on the north flank of Conejos Peak ( 3316 m elevation, core sample recovery ~470 cm), and Core 2 is from the incised Conejos River Valley bottom (2853 m elevation, core sample recovery ~120 cm). A third core (Core 3) was described by Johnson (2010) and is located in moderate relief topography near the headwaters of the Chama River (3050 m elevation, core recovery ~700cm). Ten days (July 11^th- July21st) of initial temperature data confirms microclimate variability between sites. Core 1 site was consistently ~2-4°C colder than the Core 2 site, and the Core 3 site experienced intermediate but more variable temperatures. All three cores are characterized by peat/laminated silty muds/ basal gravel stratigraphy. C-14 dates provide basal ages of 16,875 ± 172 (Cal ybp) for Core 1, ~12,500 (Cal ybp) for Core 2 and ~18,303 (Cal ybp) for Core 3. Initial pollen, grain size, organic content and magnetic susceptibility data from Core 3 reveal a cold Younger Dryas, warm early Holocene and increased climate switching frequency in the late Holocene. Analysis of Core 1 and 2 is ongoing. Geomorphic observations at Core 1 site suggest ice retreated at high elevations while lower elevation valley glaciers were still present; which accounts for the older age of the higher elevation Core 1 bog.