IDEAN   23403
INSTITUTO DE ESTUDIOS ANDINOS "DON PABLO GROEBER"
Unidad Ejecutora - UE
artículos
Título:
Cyclostratigraphy of a Tithonian carbonate ramp (Vaca Muerta Formation), Neuquén Basin, Argentina
Autor/es:
D.A. KIETZMANN; J. MARTÍN-CHIVELET; R.M. PALMA,; J.LÓPEZ GÓMEZ; M. LESCANO; A. CONCHEYRO
Revista:
AAPG BULLETIN
Editorial:
AMER ASSOC PETROLEUM GEOLOGIST
Referencias:
Año: 2011 vol. 95 p. 1459 - 1474
ISSN:
0149-1423
Resumen:
Basin to mid-ramp cyclic facies of the Tithonian Vaca Muerta Formation are exposed in the Loncoche creek section of the Neuquén Basin, Mendoza province, Argentina. This unit is characterized by a decimetre-scale rhythmic alternation of marls/shales and limestones, and extends from the early Tithonian to late Berriasian. Cyclostratigraphic studies based on a detailed facies analysis allowed the identification of cyclic patterns with frequencies within the Milankovitch band. According to biostratigraphic data, the dominant cycle in the studied section has a period of 20 ky, which correlates with the Earth’s axis precession element. Spectral analysis based on series of compacted and decompacted cycle thickness identified a subordinate frequency of about 90-120 ky, which we interpret as the modulation of the precessional cycle caused by the Earth’s orbital eccentricity. The strength of the precession signal together with the absence of a well-defined cyclicity attributable to the obliquity orbital cycle (i.e. ~ 40 ky) is in agreement with previous data from the northern hemisphere.