Silva, Gabriel L. X.
Nagy, Andre Istvan M.
Número total de Autores: 6
Afiliação do(s) autor(es):
 Univ Sao Paulo, Inst Oceanog, Sao Paulo - Brazil
 Univ Roma Tre, Dipartimento Sci, Rome - Italy
 Univ Brasilia, Inst Geociencias, Brasilia, DF - Brazil
 INPE Inst Nacl Pesquisas Espaciais, Sao Jose Dos Campos SP, SP - Brazil
 Fac Amer, Dept AI, Goiania, Go - Brazil
Número total de Afiliações: 5
Tipo de documento:
APR 21 2020.
Citações Web of Science:
The Middle Eocene Climatic Optimum (MECO) is a global warming event that occurred at around 40Ma and lasted about 500 kyr. We study this event in an abyssal setting of the Tasman Sea, using the IODP Core U1511B-16R, collected during the expedition 371. We analyse magnetic, mineralogical, and chemical parameters to investigate the evolution of the sea bottom conditions at this site during the middle Eocene. We observe significant changes indicating the response to the MECO perturbation. Mn oxides, in which Mn occurs under an oxidation state around +4, indicate a high Eh water environment. A prominent Mn anomaly, occurring just above the MECO interval, indicates a shift toward higher pH conditions shortly after the end of this event. Our results suggest more acid bottom water over the Tasman abyssal plain during the MECO, and an abrupt end of these conditions. This work provides the first evidence of MECO at abyssal depths and shows that acidification affected the entire oceanic water column during this event. (AU)