Los foraminíferos de los sedimentos cuaternarios en los alrededores de Puerto Quequén (provincia de Buenos Aires)

Abstract

The Quaternary sediments of the vicinity of Quequén are represented by Ensenadense (Pleistocene) and Platense-Lujanense (Holocene). 18 samples of the former stratum and 10 of the latter have been studied. Only 4 Ensenadense samples
and 4 Platense-Lujanense samples contained foramini/eral tests, The total number of species encountered is 31 in Ensenadense and 42 in Platense-Lujanense. The foraminiferal assemblages found in all the samples, except n2 51 (Ensenadense), are composed of the undersized specimens of the same which live now on the near shore zone of Quequén itself. This testifies to more or less the same ecological conditions which existed at that time. The sample n* 51 had some species typical of the Recent Malvin currrent, which proves that during the sedimentation of this material a lower temperature existed in the area studied. This conclusion does not agree with the generally accepted point of view on the elimate during the time of Ensenadense on the Argentine shelf. As all the species recorded in this paper were already described by the same author in the preceding ones on the Recent foraminiferal Argentine fauna, no special illustration is given here.