LATE HOLOCENE PALEOXYGENATION AND PALEOPRODRUCTIVITY OF THE PANAMA GULF
Por:
Patarroyo, G.D., Martínez, J.I.
Publicada:
1 abr 2016
Categoría:
Earth and Planetary Sciences (miscellaneous)
Resumen:
Paleocenographic conditions in the Panama Bight for the past 4000 years
were inferred by using the micropaleontological record from the deep sea
core KNR176-2-MC4 (7.27 degrees N, 78.24 degrees W; water depth 2121 m).
The epifauna-infauna relationship of deep-sea benthic foraminifera and
their diversity gradually increase up-core, which is interpreted as a
result of: (1) a decrease in the dissolved oxygen content towards the
recent and, (2) higher taphonomic effects which modify the original
composition of the microfauna. Indicative taxa of moderate oxygen
conditions, such as Uvigerina proboscidea and Oridorsalis umbonatus were
found at the base of the core. In contrast, lower oxygenation and higher
productivity conditions are inferred by the common presence of
Globobulimina affinis and Uvigerina proboscidea. Additional
paleoproductivity indicators such as Epistominella spp. and Uvigerina
peregrina were more common in the middle part of the core.
The comparison of the MC4 core micropaleontological record with several
paleoclimatic records from the Panama isthmus (the Woodhouse Lake, and
the Chilibrillo stalagmite) illustrates that a higher recurrence of El
Nino events since 5000 years BP, could be related to a higher frequency
and intensity of upwelling processes in the Panama Gulf. However, the
magnetic susceptibility of the MC4 core presents variations which cannot
be related with to a reduction in local rainfall.
Filiaciones:
Patarroyo, G.D.:
Departamento de Geología, Universidad EAFIT, Colombia
Martínez, J.I.:
Departamento de Geología, Universidad EAFIT, Colombia
gold, All Open Access, Gold
|