Resumo

JORGE-E., Mariño M.  e  ERIKA, Amaya. Lithofacies cyclicity determination in the guaduas formation (Colombia) using Markov chains. Earth Sci. Res. J. [online]. 2016, vol.20, n.3, pp.B1-B9. ISSN 1794-6190.  https://doi.org/10.15446/esrj.v20n3.44429.

Statistical embedded Markov Chain processes were used to analyze facies transitions and to determine the stacking pattern of the lithofacies of the Guaduas formation. Twelve Lithofacies were found and characterized based on lithology and sedimentary structures in four stratigraphic sections. The findings were compared with a previous assemblage of lithofacies, interpretations of sedimentary environments, and depositional systems. As a result, four depositional Systems were established.

Through the statistical analyses of facies transitions it was found that tidal facies are prevalent in the Socota section, more specifically in the upper part. Whereas in the Sogamoso, Umbita and Peñas de Sutatausa sections, fluvial facies are prevalent in the upper part of the sections, and follow a regressivesequence with more continental deposits around the upper part of the sections. For each of these sections the Markov Chain transition matrices illustrate a strong interaction between tidal facies and fluvial facies, especially in the Peñas de Sutatausa matrix, where facies 6, made up of tidal deposits, appears several times.

From the facies model and Markov Chain analyses, it is evident that the Guaduas formation is a cyclic sequence in which the Markov facies repetitions are consistent with the lithofacies analyses conducted in previous stratigraphic studies. The results reveal that the Markov Chain statistical process can be used to predict stratigraphy in order to correlate contiguous geologically unexplored areas in the Guaduas formation, where much work relating the correlation and the continuity of coal beds has yet to be done.

Palavras-chave : Litofacies; Lithofacies; reservoir environment; facies maps; Guaduas; lithofacies maps.

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