| dc.description.abstract | The Patagonia is of interest on climatic studies because is directly influenced the entire year by westerly winds from 40° S to 55° S. During the last 1000 years
there are two climatic anomalies described in Patagonia, the Medieval Climatic Anomaly (MCA) and the Little Ice Age (LIA). These two anomalies are well
described for temperature. MCA is described as a warm period which is from 800 AD to 1350 AD and LIA is described as two cold periods, the first from 1350 AD
to 1750 and the second from 1800 AD to 1900 AD. For precipitation, there are only a few studies that identify MCA and LIA as dry and wet respectively, but many
of the proxies used for precipitation, like pollen, seems not be sensitive enough for these two periods of low magnitude. Long chain leaf wax fatty acids (>C22),
total organic carbon (COT), C/N, and δ C are widely used proxies of terrestrial organic matter. Changes in the average chain length (ACL) of leaf wax fatty acids
mean changes in precipitation and/or temperature. For example, a higher ACL suggest a dry and/or more temperate climate due to the production of higher carbon
chains of leaf waxes in order to maintain water balance in the plant leaf. Here we intend to identify the MCA and LIA along a lake sediment core from lake Tranquilo
(46.6° S, 72.8°W), located in the Chilean north Patagonia using leaf wax fatty acids. Long chain leaf wax fatty acids (>C22) abundance is compared with COT, C/N,
and δ C to asses organic matter origin. ACL is used to identify MCA and LIA along the sediment core and asses the sensitivity of these proxies to MCA and LIA. | |
