G. menardii Abundance and Thermocline Ventilation in the Florida Straits over the Deglaciation

Abstract:

Sexton and Norris (2011) proposed that the absence of Globorotalia menardii in the Atlantic Ocean during glacial maximums was caused by high oxygen levels in the thermocline. In this paper we determine the relative abundance of G.menardii over the last 20,000 years in a high sedimentation rate thermocline depth core, off the coast of Florida. We compare the G.menardii abundance record to the benthic foraminiferal carbon isotope record from the same core which provides information about thermocline ventilation at the core location. We show that G.menardii population is not directly linked to ventilation at this core site. It is still unclear what controls the abundance of the G.menardii in the Atlantic Ocean.