What feeds shelf-edge clinoforms over margins deprived of adjacent land sources? An example from southeastern Brazil

Uri Schattner, Francisco José Lobo, Adrián López-Quirós, Jorge Luiz dos Passos Nascimento, Michel Michaelovitch de Mahiques

Research output: Contribution to journalArticlepeer-review

Abstract

In southeastern Brazil, the Serra do Mar coastal mountain range blocks the sediment influx from arriving at a ca. 1,500 km long continental margin comprising Santos and Pelotas basins. Despite this deprivation, the margin accumulated a ca. 1 km thick sedimentary succession since the Mid-Miocene. Examination of seismic reflection and oceanographic data indicates that shelf-margin clinoform formation exhibits a regional variability, with major sigmoidal clinoforms developed in the transitional area between both basins. Laterally, poorly developed oblique clinoforms constitute isolated depocenters along the shelf margin. The continuous clinoform development in the transitional area is attributed to the major influence on sediment transport patterns of several ocean bottom currents flowing along the margin, such as the Brazil Coastal Current, the Brazil Current and the Intermediate Water Brazil Current. These currents erode, transport and distribute sediments across the shelf break and upper slope from distant sediment sources located either north or south of the study area. The progressive southward strengthening of the Brazil Current could be responsible for a major southward sediment redistribution from the northern Campos Basin, and/or for sediment entrainment from northward-induced transport by the Brazil Coastal Current, originally derived from the De la Plata Estuary. In the transition between Santos and Pelotas basins, the Intermediate Water Brazil Current splits forming the Santos Bifurcation, allowing for a continuous depositional process and clinoform generation. We suggest that ocean bottom currents may shape other shelf-edge ‘contouritic clinoforms’ in continental margins mainly constructed by along-strike sediment transport largely driven by long-term geostrophic currents.

Original languageEnglish
Pages (from-to)293-301
Number of pages9
JournalBasin Research
Volume32
Issue number2
DOIs
StatePublished - 1 Apr 2020

Bibliographical note

Publisher Copyright:
© 2019 The Authors. Basin Research © 2019 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists

ASJC Scopus subject areas

  • Geology

Fingerprint

Dive into the research topics of 'What feeds shelf-edge clinoforms over margins deprived of adjacent land sources? An example from southeastern Brazil'. Together they form a unique fingerprint.

Cite this