Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Anais da Academia Brasileira de Ciencias 717-729 lacustrine sediment C and N isotopes pollen Atlantic Forest last millennium Little Ice Age 2010 fdi:010049047 ENG Anais da Academia Brasileira de Ciencias 0001-3765 ISI:000281689200019 3 10.1590/S0001-37652010000300019 https://www.documentation.ird.fr/hor/fdi:010049047 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers16-08/010049047.pdf 82 Horizon (IRD) This study presents paleoenvironmental data based on pollen, elemental and isotopic compositions of organic matter (TOC, N, delta C-13 and delta N-15) and C-14 dating of 170 cm lake sediment record. Samplings have been made in Lagoa Grande at Parque Estadual Turistico do Alto Ribeira - PETAR, Southern Sao Paulo State, Southeastern Brazil. The variations in relative frequencies (in percentage) of arboreal pollen along the core range between 40 and 80%. The d13C values ranged from - 23 parts per thousand h to - 30 parts per thousand h and C/N of similar to 10 to 15, indicating the contribution of terrestrial C-3 plants and algae in the sediment organic matter. The delta N-15 results presented values from 3 to 4.5 h, also suggesting a mixture of algae and terrestrial C3 plants. The 14C dating indicates modern age for the shallow horizons to similar to 1030 BP at the base of the core. A probable wetter climate in the period of similar to 370 BP to similar to 340 BP was inferred from the data set, which corresponds to a part of the period covered by the Little Ice Age (LIA). 021 ; 064 UR203 / UR182 Brésil