[1] Univ Sao Paulo, Inst Geociencias, BR-05508090 Sao Paulo, Brazil
[2] Univ Albany, Dept Atmospher & Environm Sci, Albany, NY 12222 USA
[3] Univ Fed Fluminense, Dept Geoquim, BR-24220900 Rio De Janeiro, Brazil
[4] Univ Minnesota, Dept Earth Sci, Minneapolis, MN 55455 USA
[5] Xi An Jiao Tong Univ, Inst Global Environm Change, Xian 710049, Peoples R China
[6] Univ Braslia, Inst Geociencias, Braslia, Brazil