%0 Journal Article
%T Evoluci¨®n paleoambiental de la formaci¨®n cubagua (Pen¨ªnsula de Araya) a partir de patrones de distribuci¨®n de morfogrupos de foramin¨ªferos b¨¦nticos
%A FERNANDES
%A JOHANN
%J Revista de la Facultad de Ingenier¨ªa Universidad Central de Venezuela
%D 2006
%I Scientific Electronic Library Online
%X the objective of this work is to define the morphologic distribution of the benthic foraminifera of the cubagua formation, araya peninsula (eastern venezuela). within the paleoecologic study, a total of eight morphogroups were determined by the shape of the test: plano-convex and round biumbilicade, adapted to high o2 and energy environments belonging to a neritic depth; cylindrical, adapted to conditions of low energy and oxygenation (bathyal environments); spherical/ovoid and miliolina, with a variable dominion that oscillates between disoxic and oxic environments between bathyal to external neritic depths; biconvex, related to a softer substrates and euribatic conditions; conical and conical-flattened, associated to conditions of low oxygenation and diverse depths like the previous one. from the analysis q, three morphologic assemblages were : biofacies (i), determined by the dominion of the morphogroups biconvex, spherical/ovoid and cylindrical, next to the association cyclammina cancellata, chillostomela ovoidea, sphaeroidina bulloides and rectuvigerina lamellata. biofacies (ii), corresponding to a greater abundance of the spherical/ovoid and round biumbilicade group and the disappearance of spherical/ovoid and conical-flattened morphogroups, the fossil assemblage of these biofacies are globocassidulina subglobosa, bulimina marginata and plectofrondicularia floridana. biofacies (iii), responds to the greater abundance of plano-convex and round biumbilicade morphogroups and to the set hanzawaia concentrica, amphistegina lesonii, elphidium poeyanum and buliminella elegant¨ªsima. the cubagua formation sequence begins in the late miocene in bathyal environments defined by a tectonic calm, suboxic conditions and temperatures of 5oc in average. later, a bathymetry change to a external shelf environment showed temperatures between 15 and 22oc. the final sedimentation of this formation took place in the early pleistocene with sedimentation between internal shelf to reef
%K benthic foraminifera
%K morphogroups
%K cluster
%K biofacies
%K cubagua.
%U http://www.scielo.org.ve/scielo.php?script=sci_abstract&pid=S0798-40652006000300003&lng=en&nrm=iso&tlng=en