Title of article :
Evidence for calcification depth change of Globorotalia truncatulinoides between deglaciation and Holocene in the Western Atlantic Ocean
Author/Authors :
Cléroux، نويسنده , , Caroline and Lynch-Stieglitz، نويسنده , , Jean M. Schmidt، نويسنده , , Matthew W. and Cortijo، نويسنده , , Elsa and Duplessy، نويسنده , , Jean-Claude، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
Abstract :
Measurements of the δ18O in tests of planktonic and benthic foraminifera in the Florida Straits are used to reconstruct the properties of the water column through time over the last 12 ka (Lynch-Stieglitz et al., in press). The isotopic composition of the foraminifera largely reflects the vertical density gradient. We use this reconstruction and δ18O measurements on Globorotalia truncatulinoides in a nearby core to track the depth habitat of this species from the last deglaciation to 1.6 ka B.P. Around 9 ka, G. truncatulinoides was calcifying in much shallower water than during the late Holocene. The downward migration toward its modern habitat is a regional phenomenon over the western tropical Atlantic continental slope. The cause is still unclear but we hypothesize that the shallower calcification depth may be a response to the presence of glacial melt water or to circulation changes. This study points to the value of further study of the ecology, life cycle and calcification depth for G. truncatulinoides and other planktonic foraminifera that are used to reconstruct the history of the thermocline and upper water column structure.
Keywords :
deglaciation , Calcification depth , Deep-dwelling foraminifera , Florida Straits
Journal title :
Marine Micropaleontology
Journal title :
Marine Micropaleontology