Palynological analyses of four outcrop and four subsurface sections of the Aptian-Albian siliciclastic-carbonate platform facies of the Aguardiente Formation and the Cogollo Group of the Maracaibo Basin yielded a total of 97 species of miospores 60 species of dinoflagellate cysts, freshwater protists and and acritarchs, and numerous phytoclast.

Corollina, Araucariacites and Afropollis are the most common elements, indicating close resemblance with coeval assemblages from from Brazil and Africa. Quantitative comparison of the dinoflagellate cysts and the occurence of Xenascus plotei, Achomosphaera triangulata, Kiokansium unituberculatum and some species of Subtilisphaera inidicate similirities with low latitude areas. The occurence of several species of Subtilisphaera in tropical and subtropical areas indicates initiation of provincialism of peridiacean dinocysts during the Aptian-Albian.

Four biozones are defined using marine and terrestrial species of palynomosphs. Biozones I (Early Aptian) and II (Early of Middle Aptian) have rich terrestrial assemblages and lesser of absent marine components. Biozone III (Late Aptian) is characterized by the diversification of tricolpate angiosperm pollen in northern South America and increasingly diverse dinocysts. Biozone IV is defined by the first occurrence of Elaterosporites klaszi and Xenascus plotei, determining the base to be Early Albian. The Aguardiente Formation is Aptian-Albian, the Apón Formation is restricted to the Aptian, the Lisure Formation is Late Aptian to Albian and the Maraca Formation is Albian. Regional palynostratigraphic correlation indicates major facies changes related to carbonate dominance northwards away from the siliciclastic influx from the south.

The palynofacies and palynological assemblages of the Aguardiente Formation are dominated by terrestrial organic matter. Size statistical variations of terrestrial phytoclasts and the compositional variation of the palynofacies are related to relative sealevel changes and o paleoenvironmental oxidation. Five sedimentary phases are defined indicating transgressive and regressive pulses, correlated torelative sea-level changes.

The miospore assemblages of this study are inferred to represent mainly coastal plant communities.Dinoflagellate cysts are dominated by a few by a few generalist species. Seven new species of miospores are described and new taxonomic combinatios and emendation arealso proposed. Many species of rare miospores and dinocysts are described in open nomenclature and may be new.

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¹ Universidad de Toronto, Departamento de Geología, 1994.