Onshore to offshore anatomy of a late Quaternary source-to-sink system (Po Plain-Adriatic Sea, Italy)

Alessandro Amorosi*, Vittorio Maselli, Fabio Trincardi

*Corresponding author for this work

Research output: Contribution to journalLiterature review

67 Citations (Scopus)

Abstract

In understanding the evolution of siliciclastic systems, Late Quaternary analogs may enable reliable predictive models of facies-tract architecture. The Po Plain-Adriatic Sea system, where a wealth of research has been conducted during the last 20 years, represents one of the most intensively investigated late Quaternary successions. With the aid of a chronologically well-constrained stratigraphy, paleoenvironmental evolution is tracked for the first time from fluvial to deep-marine realms, over 1000 km in length. Vertical stacking trends (onshore) and stratal terminations (offshore) are the key observations that allow identification of surfaces with sequence-stratigraphic significance (systems tract boundaries) in the distinct segments of the system. Recurring motifs in stratigraphic architecture, showing tight coupling of sedimentary responses among source area, catchment basin, and coastal and marine depocenters, reveal a cyclicity driven by glacio-eustatic fluctuations in the Milankovitch band. Due to high rates of subsidence, middle Pleistocene forced regressive systems tracts are exceptionally expanded, and the MISSe-MIS2 interval (Late Pleistocene) preserves a nearly continuous record of fourth-order (100 kyr) stepwise sea-level fall. The stratigraphic architecture of Last Glacial Maximum deposits highlights the genetic relations between channel-belt development pedogenesis, and sediment delivery to the lowstand delta, through narrow incised-valley conduits. The late glacial-Holocene succession records the last episode of sea-level rise and stabilization through well-developed patterns of shoreline transgression/regression (TST/HST) that can be readily traced updip, from offshore to onshore locations. Architectural styles across the whole system reflect a dominance of allogenic forcing in the TST, as opposed to a predominantly autogenic control on stratigraphic development in the HST. External drivers of facies architecture were also effective on millennial timescales: the Younger Dryas cold reversal, which marks the transgressive surface on land, records a short-lived episode of subaqueous progradation that is correlative onshore with widespread, immature paleosol development and small-sized channel-belt formation. Quantitative assessment of sediment budgets over different time intervals requires precise positioning of the key bounding surfaces. Based on this approach, we outline for the first time over the entire Po-Adriatic Basin an estimate of the sediment volumes stored in each systems tract. (C) 2015 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)212-237
Number of pages26
JournalEarth Science Reviews
Volume153
Early online date28 Oct 2015
DOIs
Publication statusPublished - Feb 2016

Keywords

  • source-to-sink analysis
  • sequence stratigraphy
  • sediment budget
  • Late Quaternary
  • Po Plain
  • Adriatic Sea
  • Italy
  • sequence stratigraphic analysis
  • forced-regression deposits
  • modern sediment dispersal
  • late-holocene
  • Late Pleistocene
  • coastal-plain
  • dense water
  • Mediterranean Sea
  • incised-valley
  • level change

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