Late Cretaceous hybrid (turbidite-contourite) system offshore Argentina: morphology, evolution and paleoceanographic implications

Sara Rodrigues, F. J. Hernández-Molina, Adam Kirby, Karyna Rodriguez, Neil Hodgson

Research output: Contribution to conferencePaperpeer-review

Abstract

Mixed or hybrid turbidite-contourite systems are formed by the interaction between down- and along-slope processes. These systems are characterized by a wide range of erosional and depositional features. Globally, several hybrid systems have been recognized in the Cenozoic record, however their identification in the Mesozoic remains rather modest. This issue is further aggravated by a lack of knowledge of the Mesozoic oceanic circulation patterns.
Argentina has one of the largest continental margins in the world, formed during the E-W breakup of Gondwana and diachronous opening of the South Atlantic Ocean, from south to north. This margin is characterized by a remarkable hybrid turbidite-contourite system formed during the Late Cretaceous, which offers a key sedimentary record to understand past bottom-current dynamics and their interaction with turbidity currents. Thus, the objectives of this work are: 1) to identify significant modifications and physiographic features in the Cretaceous sedimentary stacking pattern, 2) to distinguish the factors responsible for the formation and evolution of each feature and 3) to study the relationship with the main regional and paleoceanographic events. This study is based on newly acquired broadband 2D seismic reflection data provided by TGS and established regional well data.
The hybrid system comprises 23 downslope elongated drifts on the lower continental slope and rise. The drifts are characterized by asymmetric mounded morphologies, with smooth aggradational NE sides and steep, eroded SW sides. The drifts are separated by large, individual channels that start at the continental shelf/upper slope and cut through the margin’s topography. The interpretation of these results aims to propose a conceptual model for hybrid depositional systems and clarify the role and influence of bottom-current versus turbidity currents.
This project is funded by the Join Industry Project supported by TOTAL, BP, ENI, ExxonMobil, Wintershall and TGS, and it was developed in the framework of “The Drifters Research Group” at Royal Holloway University of London (RHUL).
Original languageEnglish
Publication statusPublished - 15 Dec 2019
Event58th BSRG Annual General Meeting - Royal Holloway, University of London, Egham, United Kingdom
Duration: 13 Dec 201917 Dec 2019
https://www.royalholloway.ac.uk/research-and-teaching/departments-and-schools/earth-sciences/research/drifters-bsrg/

Conference

Conference58th BSRG Annual General Meeting
Abbreviated title58th BSRG AGM
Country/TerritoryUnited Kingdom
CityEgham
Period13/12/1917/12/19
Internet address

Keywords

  • mixed systems
  • turbidite
  • contourite
  • Late Cretaceous
  • Argentina
  • seismic stratigraphy

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