2004 Denver Annual Meeting (November 7–10, 2004)

Paper No. 1
Presentation Time: 8:00 AM-12:00 PM

INITIAL POLLEN RESULTS FROM CORE MD03-2620 FROM THE CARIACO BASIN (SOUTH CARIBBEAN SEA)


DELUSINA, Irina, Geology Dept, Univ. of California, Davis, One Shields Ave, Davis, CA 95616, delusina@geology.ucdavis.edu

The Cariaco Basin, off the coast of Venezuela, acts as a depocenter for sediments of marine and terrestrial origin. The high rate of sedimentation in the basin and the anoxic conditions create a favorable setting for studying short-term paleoenvironmental changes. Pollen analyses of fifty-six samples from core MD03-2620, spanning the Last Glacial/Holocene transition and including the Younger Dryas, provide new information for reconstruction of paleoclimate and sea-level oscillations on the northern margins of South America. Dynamic changes in environmental conditions are clearly reflected in the ratio of arboreal to non-arboreal pollen. The record begins with a maximum in forest vegetation at the end of the Last Glacial. Subsequent oscillations in the arboreal to non-arboreal pollen ratio may represent the Bolling/Allerod. The minimum in forest vegetation occurs at the Younger Dryas, which is followed by a gradual increase in arboreal forms into the early Holocene. Variations in both the diversity of species and the pollen concentration correlate well with the marine oxygen isotope record.