106 



UNITED STATES NATIONAL MUSEUM BULLETIN 215 



Stratigraphic Correlation of Cipero and Lengua 

 with Other Formations 



Trinidad 



Stratigi-aphic con-elations of the Cipero and Lengua 

 formations with formations of the same age have been 

 offered by several authors, most recently by Stainforth 

 (1948b), Suter (1951) and Kugler (1953). In several 

 of the age equivalents, e. g., the Brasso formation, 

 we find the same characteristic planktonic foraminiferal 

 markers, though often in smaller numbers. Others, 

 such as the Nariva or Karamat formations may be 

 completely void of planktonic Foraminifera. Inter- 

 fingering or over- and underlying beds containing 

 planktonic faunas have, however, identified their 

 stratigraphic position in relation to the Cipero and 

 Lengua zones. The arenaceous Cipero facies is a clay 

 characterized by an arenaceous foraminiferal fauna. 

 It is lithologically almost indistinguishable from the 

 Nariva clay, which is characterised by Gravellina 

 narivaensis Bronnimann and Alveovalvulinella pozonensis 

 (Cushman and Renz) . This Nariva f aima is commonly 

 of Catapsydrax dissimilis zone age but it may also be 

 sUghtly older {Globorotalia kugleri zone) or shghtly 

 younger {Catapsydrax stainforthi zone). The arena- 

 ceous Cipero facies may occur throughout the entire 

 Cipero formation. Geographically, the Nariva forma- 

 tion is largely restricted to the Central Eange area, 

 where it underlies the Brasso formation. 



Intercalations of sands of mostly lenticular nature 

 occur in certain areas in the Globigerinatella insueta and 

 Catapsydrax stainforthi zone of the Cipero formation. 

 They are known as Retrench sands, a name that origi- 

 nates from the Retrench trigonometrical station, south 

 of San Fernando, where the Globigerinatella insueta zone 

 is developed in a radiolarian facies and is known as 

 Retrench beds. Radiolarian-rich assemblages have 

 also been found in the Globorotalia Johsi barisanensis 

 zone, e. g., at the type locality (see p. 101). 



The Herrera sands and conglomerates range in age 

 from the Globorotalia johsi johsi zone to the lower part 

 of the Globorotalia johsi robusta zone. Occasional thin 

 sands which may be attributed to the HeiTera are also 

 found in the Globorotalia johsi barisanensis zone. The 

 Karamat formation with Jarvisella karamatensis Bron- 

 nimann as marker fossil ranges from the upper part 

 of the Globorotalia johsi robusta zone (top Cipero) into 

 the Globorotalia mayeri zone (lower Lengua). 



It is of interest to note that formations such as the 

 Karamat or Nariva, which may attain several thousand 

 feet in thickness, were deposited within a comparatively 

 short time interval. 



The Brasso formation, in contrast to the Cipero 

 formation contains more calcareous benthonic Foram- 

 inifera, though planktonic forms commonly occur 

 in sufficient numbers to allow correlation with the 

 fa\mal zones of the Cipero and Lengua formations. 

 The Brasso formation consists predominantly of clays 

 with their main development in the Central Range 



area. Renz (1948, p. 89) recognized the following 

 members from top to bottom: Los Atajos, Navarro 

 River, Tunnel HiU, and Esmeralda. These members 

 are here tentatively considered to range in age from the 

 Globigerinatella insueta zone to the Globorotalia mayeri 

 zone (see text-fig. 20). 



Recently the Los Atajos member has been placed in 

 the lower part of the ManzaniUa formation, which 

 starts with the Brasso conglomerate. The Tamana 

 formation consists of a coralliferous algal reef limestone 

 interfingering with the Globorotalia mayeri and Globo- 

 rotalia menardii zones of the Lengua formation. 



The Ste. Croix formation, originally described as a 

 series of foraminiferal silts and clays with minor beds 

 of sand, is now regarded as a member of the Brasso 

 formation. It is slightly older than the Esmeralda 

 member and represents an extension to the south of 

 the Central Range where it is commonly foimd iater- 

 bedded in the Cipero formation. Cushman and Renz 

 (1947) described the foraminiferal fauna of the Ste. 

 Croix formation, recording 10 planktonic species, in- 

 cluding Globigerinatella insueta Cushman and Stain- 

 forth from the Trinidad Point calcareous clay locality. 

 On the basis of this species, this part of the Ste. Croix 

 formation was correlated with Cushman and Stain- 

 forth's Globigerinatella insueta zone (Zone II), whereas 

 the Ste. Croix calcareous clay from the type locality 

 was considered to be slightly yoimger. In addition to 

 Globigerinatella insueta, Bronnimann (1950, p. 81) also 

 reported Catapsydrax dissimilis from the Ste. Croix 

 calcareous clay locality; hence these beds are in the 

 Catapsydrax stainjorthi zone. 



Caribbean and Gulf Coast Region 



Correlations of the Cipero and Lengua formations 

 with formations of the Caribbean region outside 

 Trinidad are here restricted to sections either studied 

 by the author himself or discussed with other workers. 



One of the most complete and best described sections 

 is doubtless that of the Agua Salada group in the State 

 of Falc6n, Venezuela (Renz, 1948). The general 

 aspect of the rich foraminiferal faima is more like 

 that of the Brasso formation of Trinidad, which is rich 

 in benthonic Foraminifera. However, no diSiculties 

 have been found in correlating Renz's Agua Salada 

 zones with those of the Cipero and Lengua formations 

 (see text-fig. 20). 



Beckmann (1953) described the Foraminifera from 

 the Eocene-Oligocene Oceanic formation of Barbados. 

 Discussions with this author indicate that the OHgocene 

 part of the Oceanic formation, which is rich in plank- 

 tonic Foraminifera, can readily be correlated with the 

 zones of the lower part of the Cipero formation (see 

 text-fig. 20). The Bissex Hill formation is an age 

 equivalent of the Globigerinatella insu£ta zone and the 

 overlying Globigerina marls of the lower Globorotalia 

 johsi zone, sensu lato. 



Several samples from the Antigua limestone of 

 Antigua were found to contain Globigerina ciperoensis 

 BoUi, sensu lato. These beds may therefore be cor- 



