NOTA TECNICA
CHAPAPOTAL MEMBER, NEW NAME FOR CACHIPO MEMBER OF CARAPITA FORMATION
(MIEMBRO CHAPAPOTAL NUEVO NOMBRE DEL MIEMBRO CACHIPO DE LA FORMACION CARAPITA)
by J. A. Sulek[1]
and R. M. Stainforth[2]
In a paper presented at the Fourth Caribbean Geological Conference, 1965, J. L. Lamb and J. A. Sulek described the turbidite sands of the Carapita Format: in Eastern Venezuela and named them the Cachipo Member. Pending publication of the transactions of the Conference, an abridged version of the paper was published in order to make the new name available for the revised edition of the Stratigraphical Lexicon of Venezuela, now in preparation.
In both versions it is stated that the name Cachipo has never appeared in the geological literature, neither in reference to stratigraphy nor to oilfield operations. Very unfortunately, we have now realized belatedly that this statement is untrue. At the III Congreso Geológico Venezolano in 1959, Felix Balda presented a study of the beds outcropping near Chiguana on the Gulf of Cariaco, and his paper was published in 1960 in the Memoria of the Congress. Balda named the beds in question the “formación Chiguana”, but as a sub-unit within the sequence he designated the “lutitas de Cachipo” (p. 930). Although his description is brief, it is adequate to validate Balda’s name, which he states is derived from Punta Cachipo where the best exposures of these shales are encountered.
It follows that the name Cachipo, as applied to a member of the Carapita Formation, was a homonym of a term already existing in the stratigraphic literature of Venezuela, hence it is invalid under the Code of Stratigraphic Nomenclature (1961, Art 11). It is therefore necessary to substitute a new name, and we hereby propose the term Chapapotal Member, to replace the Cachipo Member of Lamb and Sulek.
The name Chapapotal is taken from the group of exploration wells Chapapotal -1, -2, -3 and which were themselves named for tar-seeps (“chapapotales” in the vicinity. These wells, drilled by Creole Petroleum Corporation, are located just outside and northeast of the producing limits of the Jusepín oilfield (see map and. cross section, Fig. 1). Chapapotal -1, drilled in 1936, did not actually encounter sands in the Carapita Formation, but it later became an important control point in delimiting their subsurface truncation below the unconformable La Pica Formation. Chapapotal -2 and -4, drilled many years later, did encounter the sands which we here name the Chapapotal Member, and were instrumental in defining the productive limits of the Northeast Extension of the Jusepín oilfield.
In conclusion, we wish to state clearly that this note is only intended to modify the name of the member. Its type area (Cachipo Block) and type locality (Well Q-297, 5635-8075') remain as defined by Lamb and Sulek.
References
AMERICAN COMMISSION ON STRATIGRAPHIC NOMENCLATURE, 1961
“Code of stratigraphic nomenclature”
Amer. Assoc. Petrol. Geol., Bull., vol. 45, no. 5, p. 645-665
BALDA, F. , 1960
“Estructura geológica de Chiguana, Peninsula de Araya, Estado Sucre”
III Congr. Geol. Ven., Mem., tomo II, p. 928-934
COMISION AMERICANA DE NOMENCLATURA ESTRATIGRAFICA, 1961
“Código de nomenclatura estratigráfica”
Editorial Stylo, Mexico, D.F.
LAMB, J. L. & SULEK, J.A., in press
“Miocene turbidites in the Carapita Formation of Eastern Venezuela”
4th Carib. Geol. Conf., Trinidad, March-April, 1965
— & —, 1965
“Definition of the Cachipo Member of the Carapita Formation”
Asoc. Ven. Geol. Min., Pet., Bol. Inf., vo1. 8, no. 4, p. 111-114