STUDIES IN FORAMINIFERA 



107 



TRINIDAD 



MJVm a MRAMAT 



FORMATIONS 

 ARtlUC. CIPIHO, 



CATAPSrORAX 

 DISSIHILIS 



SLOBieCRINA 

 CIP£ROeNSIS 

 CIPEROENSIS 

 SLOBOROTALIA 

 OPIMA OPIHA 



SLOBISERINA 

 AUtPLIAPeRTURA 



BRASSO FORMATION 

 (RCNZ 1948) 



HgRRCRA 

 MEUBER <. 



ARENACEOUS 

 CIPERO 

 MEMBER 



NAVARRO 



RIVER 



MEMBER 



TUNNEL HILL MB. 

 ESMERALDA 

 MEMBER 



VENEZUELA 



VALVULINERIA 

 HERRICKI 



SLOBOROTALIA 

 FOHSI 



SIPH06ENERINA 

 TRANSVERSA 



UVISemHELLA' 

 SPARSieOSTATA 



BARBADOS 



ISEHN I94»; 

 BECKMANN, 

 PRIVATE REPORT) 



SLOBISERINA 

 MARLS 



NOT YET RECORDED 

 WITH PLANKTONIC 

 FORAMINIFERA 



OCEANIC 

 FORMATION 



ANTieUA 

 LIMESTONE 



SULF COAST 

 (AKERS, PRIVATE 

 REPORT AND ISSS) 



TEXTULARIA 

 STAPPERI 



CIBICIDES 



CARSTENSI 



OPIMA 



AMPHISTESINA SP. 



ANAHUAC 

 FORMATION 



CHICKASAWHAY 

 FORMATION 



Figure 20, — Stratigraphic correlation of the Cipero and Lengua formations with other formations in Trinidad, the Caribbean, and 



the Gulf Coast region. 



related with the Globigerina ciperoensis ciperoensis 

 or the Globorotalia opima opima zones of the Cipero 

 formation. 



An attempt has also been made to correlate Gulf 

 Coast sediments of Oligocene-Miocene age with the 

 Cipero formation (see text-fig. 20). This is based 

 on discussions with W. H. Akers and on his (1955) 

 report on the subject. Samples from the Vicksburg 

 stage which con-elate with the Globigerina ampliaper- 

 tura zone have also been examined by the present 

 author. 



It is well known that the Oligocene-Miocene plank- 

 tonic Foraminifera which are here described from 

 Trinidad are not restricted to the Caribbean and Gulf 

 Coast region. For example, identical forms have been 

 described from Colombia (Fetters and Sarmiento, 



1956) and from Peru (Stainforth, 1948a). An attempt 

 has recently been made by Drooger (1956) to arrive 

 at a transatlantic correlation of the Oligo-Miocene by 

 means of Foraminifera. He places special emphasis 

 on the planktonic Foraminifera and some encoiu-aging 

 preliminary results have already been obtained. 



Such studies as Le Roy's (1948, 1952) indicate that 

 similar or identical planktonic foraminiferal assemblages 

 also occm- in Oligocene-Miocene sediments of the Far 

 East. Thus, it may safely be concluded, as with the 

 Cretaceous and lower Tertiary forms, that the Oligo- 

 cene-Miocene planktonic Foraminifera have a world- 

 wide distribution, limited only by locally adverse 

 environmental conditions. They offer, where present, 

 an excellent means for age determination, zonation 

 and long range correlation. 



Systematic Descriptions 



Sixty planktonic foraminiferal species and subspecies 

 belonging to fifteen genera are described or listed. A 

 full description is given only for the new species and 

 subspecies. Synonymy lists are restricted to the 

 original description and to species or subspecies de- 

 scribed from the Caribbean and Gulf Coast region. 



The stratigraphic range within the Cipero and 

 Lengua formations is given for each species or sub- 



species. Several species occur also in the upper 

 Eocene, and this is mentioned in the specific descriptions. 

 With the change of the ecologic conditions at the 

 end of the Lengua time all planktonic Foraminifera 

 disappeared locally. Some of them may have become 

 extinct at this time, but it is known that many species 

 continued to live in other more favourable regions, and 

 several of these species are known from Recent seas. 



