Stratigraphic context: cyclostratigraphy and magnetostratigraphy of the Vaca Muerta Formation

LEANZA, H.A.; KIETZMANN, D.A.; IGLESIA-LLANOS, M.P.; KOHAN MARTINEZ, M.

AAPG MEMOIR

The American Association of Petroleum Geologists

Lugar: Tulsa; Año: 2020 vol. 121 p. 39 - 60

0271-8529

The Vaca Muerta Formation belongs to a retro-arc setting, with a fast flooding episode at its very base, probably favored by an under filled depocenter and uplifted peripheral zones, in which the oceanic water penetrated through sudden ruptures along the incipient Andean arc, as a consequence of the Late Jurassic inversion. The Vaca Muerta Formation forms part of the Lower Mendoza Subgroup, and is defined as the highly bituminous shales (2-8 % TOC) deposited between the sharp contact with the continental Tordillo and/or the Quebrada del Sapo Formations or equivalent subsurface units and the Huncalican (Intravalanginian) unconformity. Its age span is encompassed between the late Lower Tithonian Virgatosphinctes andesensis to the Lower Valanginian Lissonia riveroi ammonite Zones. In association with classical stratigraphic characteristics of this unit, this chapter presents for the first time a ciclostratigraphic and magnetostratigraphic column, displaying an accurate time table for the Vaca Muerta deposition. Recent relevant cyclo- and magnetostratigraphic data is provided