REVISTA CIENCIA E INGENIERÍA ISSN: 1316-7081
Artículo <strong>de</strong> Investigación Revista Ci<strong>en</strong>cia e Ing<strong>en</strong>iería. Vol. 28, No. 1, pp. 55-60, dic.–mar., 2007. ISSN 1316-7081 <strong>Facies</strong> <strong>sedim<strong>en</strong>tarias</strong> <strong>d<strong>el</strong></strong> <strong>pérmico</strong> <strong>en</strong> <strong>el</strong> <strong>flanco</strong> <strong>surandino</strong> <strong>de</strong> V<strong>en</strong>ezu<strong>el</strong>a Permian sedim<strong>en</strong>tary facies at southern region of V<strong>en</strong>ezu<strong>el</strong>an An<strong>de</strong>s Viscarret*, Patxi y Laya, Juan Dpto. <strong>de</strong> Geología G<strong>en</strong>eral. Escu<strong>el</strong>a <strong>de</strong> Ing<strong>en</strong>iería Geológica. Facultad <strong>de</strong> Ing<strong>en</strong>iería. Universidad <strong>de</strong> Los An<strong>de</strong>s. Mérida. V<strong>en</strong>ezu<strong>el</strong>a. *patxi@ula.ve Recibido: 12-03-2004 Revisado: 25-11-2006 Resum<strong>en</strong> En <strong>el</strong> <strong>flanco</strong> <strong>surandino</strong> <strong>de</strong> V<strong>en</strong>ezu<strong>el</strong>a un ciclo <strong>de</strong> sedim<strong>en</strong>tación <strong>de</strong> Paleozoico Superior está repres<strong>en</strong>tado por las rocas <strong>de</strong> Sabaneta y Palmarito, formaciones <strong>de</strong> los An<strong>de</strong>s <strong>de</strong> Mérida al suroeste <strong>d<strong>el</strong></strong> Lago <strong>de</strong> Maracaibo aflorantes <strong>en</strong> las adyac<strong>en</strong>cias <strong>de</strong> la población <strong>de</strong> Mucuchachí y Aricagua. La problemática que se pres<strong>en</strong>ta <strong>en</strong> <strong>el</strong> estudio <strong>de</strong> las cu<strong>en</strong>cas <strong>d<strong>el</strong></strong> Paleozoico <strong>en</strong> V<strong>en</strong>ezu<strong>el</strong>a son <strong>de</strong> innumerables interrogantes, <strong>de</strong>bido a la escasez <strong>de</strong> información para la interpretación veraz e irrefutable <strong>de</strong> una teoría que explique <strong>el</strong> <strong>de</strong>sarrollo <strong>de</strong> los ciclos geológicos <strong>d<strong>el</strong></strong> Paleozoico. En la sección correspondi<strong>en</strong>te a la Formación Palmarito <strong>de</strong> la quebrada El Palmar se analizaron los resultados obt<strong>en</strong>idos a partir <strong>de</strong> la información <strong>de</strong> campo y petrográfica exist<strong>en</strong>te con la finalidad <strong>de</strong> <strong>de</strong>terminar las asociaciones <strong>de</strong> facies, biofacies e icnogéneros <strong>de</strong> la Formación Palmarito, a<strong>de</strong>más <strong>de</strong> sus ambi<strong>en</strong>tes. El <strong>pérmico</strong> <strong>d<strong>el</strong></strong> área estudiada es una unidad sedim<strong>en</strong>tológicam<strong>en</strong>te y estratigráficam<strong>en</strong>te bién <strong>de</strong>finida. A partir <strong>d<strong>el</strong></strong> análisis bioestratigráfico <strong>de</strong> los grupos faunales. se pudo establecer una edad <strong>de</strong> Pérmico (Cisuraliano?-Guadalupiano?) pert<strong>en</strong>eci<strong>en</strong>te a la Formación Palmarito <strong>en</strong> don<strong>de</strong> resaltan calizas tipo Mudstone, Packstone, Wackeston, Rudstone, Dolomitas, a<strong>de</strong>más <strong>de</strong> limolitas y lutitas <strong>de</strong> orig<strong>en</strong> marino muy fosilíferas con alto cont<strong>en</strong>ido <strong>de</strong> materia orgánica que pudies<strong>en</strong> haber g<strong>en</strong>erado hidrocarburos. A<strong>de</strong>más se observaron ar<strong>en</strong>iscas con porosida<strong>de</strong>s excepcionales <strong>de</strong> hasta 30% aproximadam<strong>en</strong>te, pudi<strong>en</strong>do <strong>de</strong> esta manera, servir como roca reservorio. No se observaron r<strong>el</strong>aciones <strong>sedim<strong>en</strong>tarias</strong> <strong>en</strong>tre <strong>el</strong> Paleozoico inferior (Formación Caparo) y superior (Formaciones Sabaneta y Palmarito) tales como concordancias y sedim<strong>en</strong>tación transicional; adicionalm<strong>en</strong>te se evid<strong>en</strong>cian gran<strong>de</strong>s saltos estratigráficos por lo que se concluye que estas secu<strong>en</strong>cias no se pued<strong>en</strong> r<strong>el</strong>acionar como ev<strong>en</strong>tos continuos <strong>en</strong> la misma cu<strong>en</strong>ca. Se recomi<strong>en</strong>da realizar estudios <strong>de</strong> COT (Carbono Orgánico Total) a muestras <strong>de</strong> edad pérmica, bioestratigrafía <strong>de</strong> alta resolución a las muestras recolectadas. Palabras claves: Paleozoico superior, asociación <strong>de</strong> facies, petrografía, An<strong>de</strong>s v<strong>en</strong>ezolanos Abstract An upper Paleozoic sedim<strong>en</strong>tation cycle has be<strong>en</strong> found in the southern region of the V<strong>en</strong>ezu<strong>el</strong>a An<strong>de</strong>s, repres<strong>en</strong>ted by rocks of Sabaneta and Palmarito Formations, located at the southeast of Maracaibo Lake, near to the Mucuchachí and Aricagua towns. Own to the lack of geological data nee<strong>de</strong>d to give, in a g<strong>en</strong>eral way, proper interpretation of Paleozoic geological cycles. This work studies the associations of facies, in the section of Palmarito Formation located along to the El Palmar creek. This analysis is based on fi<strong>el</strong>d and petrography existing data. The Permic of the studied area is a w<strong>el</strong>l <strong>de</strong>fined sedim<strong>en</strong>tical and stratigraphical unit. From the biostratigraphic analysis of faunal group it was possible to establish an age for the Permic (Cisuralian?-Guadalupian?) b<strong>el</strong>onging to the Palmarito Formation, where it is common to find Mudstone, Packstone, wackestone, Rudstone and dolomites limestone’s-like rocks as w<strong>el</strong>l as fossil marine’s limolitas and shale whit a high <strong>de</strong>gree of organic cont<strong>en</strong>t. Furthermore, it was observed sandstones with a <strong>de</strong>gree of almost 30% of porosity. Additionally, it is evid<strong>en</strong>t the stratigraphic discontinuities leading to the conclusion that these sequ<strong>en</strong>ces can be r<strong>el</strong>ated as continuous ev<strong>en</strong>ts of the same geographical basin. It is recomm<strong>en</strong><strong>de</strong>d to make a Total Organic Carbon analysis and a high resolution biostratigraphy of samples from the Permic age in this region Key words: Upper Paleozoic, facies associations, petrography, V<strong>en</strong>ezu<strong>el</strong>an An<strong>de</strong>s Revista Ci<strong>en</strong>cia e Ing<strong>en</strong>iería. Vol. 28, No. 1, diciembre-marzo, 2007
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