Facies sedimentarias del pérmico en el flanco surandino de Venezuela

Abstract

An upper Paleozoic sedimentation cycle has been found in the southern region of the Venezuela Andes, represented by rocks of Sabaneta and Palmarito Formations, located at the southeast of Maracaibo Lake, near to the Mucuchachi and Aricagua towns. Own to the lack of geological data needed to give, in a general 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 field and petrography existing data. The Permic of the studied area is a well defined sedimentical and stratigraphical unit. From the biostratigraphic analysis of faunal group it was possible to establish an age for the Permic (Cisuralian?-Guadalupian?) belonging to the Palmarito Formation, where it is common to find Mudstone, Packstone, wackestone, Rudstone and dolomites limestone’s-like rocks as well as fossil marine’s limolitas and shale whit a high degree of organic content. Furthermore, it was observed sandstones with a degree of almost 30% of porosity. Additionally, it is evident the stratigraphic discontinuities leading to the conclusion that these sequences can be related as continuous events of the same geographical basin. It is recommended to make a Total Organic Carbon analysis and a high resolution biostratigraphy of samples from the Permic age in this region.