Abstract
The Nabón basin is part of several Miocene intermontane basins related to Andean uplift, continental arc formation and coeval deformation during subduction of the Nazca plate under the South American continent. The basin sequence consists of fluvial, alluvial fan, lacustrine, and pyroclastic mass-flow deposits corresponding with intereruptive and syneruptive stages of basin-fill history. Combined zircon fission-track and palaeomagnetic measurements suggest that the series lies within the 4r chron (ca. 8.5–7.9 Ma). It overlies unconformably the ignimbrite basement dated at ca. 26-19 Ma. Synsedimentary tectonic deformation in the basin is manifested by a master reverse fault along the western margin, differential basement block uplift and related sedimentary bedding geometries such as cumulative sedimentary wedges. The spatial orientation of the tectonic and sedimentary features indicates that the basin underwent WNW-ESE maximal shortening during the fill stage. The short-lived sediment-fill history may be explained, either by subduction-related contractional pulses also recognized in the Peruvian and Colombian Andes or, by the particular position of the basin in the central axial part near the weak fault of a regional translational system.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
