Stalagmite based paleoclimate reconstruction, northern Venezuela: A record of Caribbean Holocene climate change

Northern Venezuela stalagmites from Cueva Zarraga were analyzed for their delta 18O and delta13C values and dated using U/Th disequilibrium. Goals included producing a terrestrial record of Caribbean/South American climate change; determine the expressions of Northern Hemisphere climate change in the tropics; and tracking the migration of the Inter-Tropical Convergence Zone (ITCZ) throughout the Holocene. The record extends from 11,000 yBP to present and captures the early Holocene transition from the cooler climate of the Last Glacial Maximum to the warmer wetter Holocene, correlating well with regional and high-latitude records. Insolation driven migration of the ITCZ controls climate change for the majority of the Holocene, up until ∼ 3,000 yBP when climatic change and insolation are decoupled. The decoupling has been attributed to less migration of the ITCZ or higher variability in El Nino activity. Timing is suggestive of an anthropogenic cause from increased population and/or changes in agricultural practices.