Abstract

A quantitative palynological study of the Paleocene/Eocene transition in western Venezuela was undertaken to detect and analyze possible cyclic patterns. Two different methodologies were used, palynocycles and ecologs, and their results are compared. A total of 237 outcrop samples from three formations deposited in continental to coastal environments were analyzed for pollen and fern spores.

Several palynological cycles are recorded and correlated with third-order global eustatic cycles. A high-frequency cyclicity of ca. 220,000-year period also was found. Both methodologies recorded the same cyclic patterns and can be considered complementary. Ecologs are easier to use, but have less interpretative potential. Palynocycles are more complex, but also more descriptive and help detect small hiatuses. Diversity values reach maxima at cycle boundaries and their minima in the middle of cycles. This distribution has been interpreted in terms of different palynomorph sources under conditions of high and low sea level. During the Paleocene/Eocene transition, diversity shows a constant ascending trend, probably due to a long-term, worldwide climatic warming.

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