The Genera Globigerina and Globorotalia in the Paleocene-Lower 

 Eocene Lizard Springs Formation of Trinidad, B.W. I. 



By Hans M. BoUi ' 

 Introduction 



Authors of previous papers on the foraminiferal 

 ■l\- fauna of the Lizard Springs formation restricted 

 their observations entirely to surface sections. Because 

 of complex tectonic conditions in Central and South 

 Trinidad, most of the Lizard Springs outcrops are small 

 isolated slipmasses that are often confined to a single 

 zone and therefore are not suitable for comprehensive 

 stratigraphic and evolutionary studies. The Lizard 

 Springs formation as encountered in wells often consists 

 of similar slipmasses. In a few boreholes, however, 

 continuous and apparently imdisturbed sections of over 

 1,000 feet in thicloiess have been penetrated. These 

 sections, combined with surface information, now allow 

 a much more complete and reliable study of the foram- 

 iniferal species and their stratigraphic ranges than was 

 previously possible. 



Although the planktonic Foraminifera are strongly 

 predominant in many samples of the Lizard Springs 

 formation, not much attention was paid to them until 

 Bronnimann's paper on the Globigerinidae appeared in 

 1952. The usefulness of planktonic Foraminifera for 

 zoning has already been proved in older and younger 

 sediments (Upper Cretaceous, Eocene-Miocene). The 

 present study of Olohigerina and Oloborotalia shows that 

 a similar pattern of comparatively short ranges for 

 most species also prevails in the Paleocene-lower Eocene 

 Lizard Springs formation of Trinidad. 



On the basis of benthonic Foraminifera, the Lizard 

 Springs formation was previously subdivided into a 

 lower and an upper zone. The stratigraphic distribu- 

 tion of the planktonic Foraminifera in the more com- 

 plete sections now available allows eight well-defined 

 zones to be distinguished, five of which are regarded as 

 of Paleocene age (lower Lizard Springs) and three as of 

 lower Eocene age (upper Lizard Springs). As a rule 

 the fauna of the basal part of the Lizard Springs forma- 

 tion is entirely arenaceous. The arenaceous Lizard 

 Springs facies, which is given zonule rank, may however 

 also occur in higher parts of the Paleocene portion of 

 the Lizard Springs formation. Beds almost indistin- 

 guishable from this facies may possibly also replace 

 part of the calcareous Upper Cretaceous Guayaguayare 

 formation. Furthermore it is a time and facies equiva- 

 lent of the Chaudiere formation of the Central Range. 



Preliminary examination of Paleocene and lower 

 Eocene samples from widely separated regions such as 

 Venezuela, the United States Gulf Coast area, Peru, 

 North Africa, and Europe suggests that a zonation of 

 the Paleocene-lower Eocene on the basis of planktonic 

 Foraminifera can be a useful tool for interregional 

 correlation. 



Stratigraphy 



For the history and earlier zonation of the Lizard 

 Springs formation, reference is made to Cushman and 

 Renz (1946). On the basis of benthonic smaller 

 Foraminifera, these authors subdivided the formation 

 into a lower and upper zone and a probable late Maes- 

 trichtian to Danian age was suggested for both. A 

 short account of a subsequent controversy on the 

 Cretaceous age of the Lizard Springs formation was 

 given by Bolli (1952), who regarded the age as Paleo- 

 cene. Bronnimann (1952) maintained the subdivision 

 of the formation into a lower and upper zone, both of 

 Paleocene age. 



These authors restricted their observations on the 

 Lizard Springs formation to the type locality as 

 described by Cushman and Renz, and to a few other 

 surface samples. The type locality represents a slip- 

 mass within a sjTiorogenic clay-boulder bed of Miocene 

 age. It was already stressed by Cushman and Renz 

 that this section, measuring about 250 feet, is strongly 

 disturbed and incomplete. Other Lizard Springs out- 

 crops in central and south Trinidad have the same 

 shortcomings and often consist of only a single zone. 

 Similar conditions were previously mentioned for Upper 

 Cretaceous sediments (BoUi, 1956). It is therefore 

 fortunate that there is available a number of carefully 

 recorded favorable subsm-face profiles which allow the 

 study of fairly continuous sections of Paleocene and 

 lower Eocene sediments. 



The most complete of these profiles was found in the 

 subsurface section of Trinidad Leaseholds, Ltd., well 

 Guayaguayare 159. This well is situated in southeast 

 Trinidad, in the same general area as the original 

 Lizard Springs type locality. Here, six of the nine 

 established subdivisions are represented by cores in 



' Trinidad Oil Company, Ltd. (formerly Trinidad Leaseholds, Ltd.), Polnte-4- 

 Plerre, Trinidad, B. W. I. 



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