Abstract
In a recent article, Pazos et al . (2008, p. 343) claim that ‘the Zanja del Tigre Formation (Uruguay) represents a glacial influenced succession deposited during the Neoproterozoic, correlative with one of the glaciations described in the Kalahari Craton, prior to Kalahari–Rio de la Plata assembly in the proto-western Gondwana margin'. However, we question the two lines of evidence that Pazos et al . (2008) put forth in their paper to constrain the age of this unit and to support a glacial event. Pazos et al . (2008, p. 350, and fig. 4) consider the Zanja del Tigre Formation as part of the Lavalleja Group. This view, however, is incompatible with existing interpretations. According to the latest compilations of the geology of Uruguay (Bossi et al . 1998; Bossi & Ferrando 2001), the Zanja del Tigre Formation is part of the Carape Group, which is stratigraphically below the Lavalleja Group. In fact, the Carape and the Lavalleja groups have long been considered independent lithostratigraphic units (e.g. Bossi & Navarro 1991), perhaps even belonging to different ‘terranes' or ‘blocks' (Gaucher et al . 2004). A recent geochronological study (not available to Pazos et al . 2008, at the time of writing) based on detrital …
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.