New evidences of positive tectonic inversion in cretaceus sequences of the block VIII area, Maracaibo basin, Venezuela Nuevas evidencias de inversión tectónica positiva a nivel de secuencias cretáceas en el área bloque quot;VIIIquot;, cuenca de Maracaibo-Venezuela

Martinez, F. J.; Castillo J.F.; Bastardo, M

Abstract

The goal of this research is to define the geometries of structural elements that show evidence of positive tectonic inversion within the Maraca and Apón formations (Lower-Middle Cretaceus) in block "VIII", central part of the Maracaibo basin, Venezuela, in order to clarify the geologic architecture of the substratum. By means of visualization and interpretation of N-S and E-W seismic profiles, time slices from a 3D cube of 253km2 in extension and the integration of seismic data with data of 24 wells (formational tops, electrical curves, checkshot), it was observed as the Cretaceus thrusted slightly and folded along strike-slip faults forming "flower structures" and also in inverted and thrust listric faults forming "harpoon structures". Faults A and B, oblique and parallel to the Lama and Pueblo Viejo ENE faults, are strike-slip dextral overlapping faults that propagate in depth beyond the Jurásic-Cretaceus interface, controlling the inversion of the smaller structures confined between them and creating a compressed zone between the two. It is concluded that the observed tectonic inversion is moderate or partial. Major and minor strike-slip faults and "harpoon structures" are producing the Cretaceus inversion. The observed structures are related in their origin with the escape of the Maracaibo Block during the Late Miocene, and with the Andean Orogenesis of the Early Miocene, as its direction and vergence are similar to Andean NNE-NE structures and the Eocene discrepancy is slightly folded.

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Título según SCOPUS: New evidences of positive tectonic inversion in cretaceus sequences of the block VIII area, Maracaibo basin, Venezuela [Nuevas evidencias de inversión tectónica positiva a nivel de secuencias cretáceas en el área bloque quot;VIIIquot;, cuenca de Maracaibo-Venezuela]
Título de la Revista: INTERCIENCIA
Volumen: 33
Número: 6
Editorial: Asociación Interciencia
Fecha de publicación: 2008
Página de inicio: 424
Página final: 428
Idioma: Spanish
URL: http://www.scopus.com/inward/record.url?eid=2-s2.0-49149088902&partnerID=q2rCbXpz
Notas: SCOPUS