A Pliocene-Pleistocene temperature reconstruction from the tropical Andes of Colombia 

<p>We provide a Plio-Quaternary quantitative temperature record based on the distribution of bacterial membrane lipids; branched glycerol dialkyl glycerol tetraethers (brGDGTs) preserved in lake sediment of the Funza-II core in the Sabana de Bogot&#225; (2500 m.a.s.l.), Eastern Cordillera of Colombia (~4&#176;N). Using a refined age model based on 4 new zircon U-Pb dates from ash layers that place the base of the core at around ~4 Ma, we show that Pliocene temperatures were ~2.2 &#177; 2.0&#176;C warmer than Mid-Late Pleistocene temperatures. If the Pliocene eastern tropical Pacific were as warm as it becomes during major El Ni&#241;o events today, the teleconnection to the Eastern Cordillera of Colombia could account for a warmer Pliocene than present-day climate by 2&#176;C, without a pantropical change in temperature. These temperature estimates are the only terrestrial tropical record within 5&#176; of the equator for Pliocene time.</p>