Comment on "Tethyan calpionellids in the Neuquen Basin (Argentine Andes), their significance in defining theJurassic/Cretaceous boundary and pathways for Tethyan-EasternPacific connections" by R. Lopez-Martínez, B. Aguirre-Urreta,M. Lescano, A. Concheyro,

KIETZMANN, DIEGO A.; IGLESIA LLANOS, MARÍA PAULA

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2018 vol. 84 p. 444 - 447

0895-9811

In this contribution, Lopez-Martínez et al. (2017) state that they achieved to define the position of the Jurassic- Cretaceous (J-K)boundary from the finding of Tethyan calpionellids in the VacaMuerta Formation at Las Loicas section, Neuquen Basin. The authorsanalyzed ten samples in a reduced interval of the Vaca MuertaFormation where the boundary would lie.Las Loicas section represents a basinal section of c. 270 m withlarge covered intervals (c. 90 m) bearing ammonites of the LowerTithonian Virgatosphinctes mendozanus Zone to at least the UpperBerriasian Spiticeras damesi Zone (Aguirre-Urreta et al., 2014). Theupper part is covered.We do consider that the data presented by Lopez-Martínez et al.are important for the discussion on the J-K boundary in Argentina,provided that the knowledge of calpionellids in the Neuquen basinis very poor. The aim of this Comment is to better explain some dataderived from previous biostratigraphic and magnetostratigraphicstudies (i.e. Fernandez Carmona and Riccardi, 1999, Kietzmannet al., 2011a; Kietzmann, 2017; Iglesia Llanos et al., 2017) thatLopez-Martínez et al. (2017) failed to interpret correctly.