Application paléoécologique de la méthode d'analyse factorielle en composantes principales: interprétation des microfaunes de foraminifères planctoniques quaternaires en méditerranée. II. Étude des espèces de méditerranée orientale

The principal component analysis method is applied to the study of associations of different Pleistocene and Holocene planktonic Foraminifera in five cores from the eastern Mediterranean. Comparison of the fossil foraminiferal distribution with the distribution of living species leads to grouping of the fossil microfauna on the basis of paleoecological controls. Factor 1 is interpreted as representing thermal control. We recognize as warm-water species Globigerinoides trilobus, Globigerinoides trilobus sacculifer, Orbulina universa, Globigerinella siphonifera, Globigerinoides ruber. Cold-water species are Globigerina pachyderma, Globorotalia scitula, Globigerina quinqueloba, Globigerinita glutinata. Species considered to be of intermediate character are Globigerina bulloides, Globorotalia inflata and Globorotalia truncatulinoides. Factor 2 also leads to the grouping of these last species and may reflect the contributing influence of productivity phenomena. A quadratic liaison interpreted as the “Guttman effect” relates factors 1 and 2. Factor 3 introduces complications resulting from apparently sporadic, irregular events affecting the distribution of certain species, notably Globoratalia inflata, Globorotalia truncatulinoides and Globigerina dutertrei.