Ups and downs of the Mississippi delta

Michael D. Blum, Jonathan H. Tomkin, Anthony Purcell, Robin R. Lancaster

Research output: Contribution to journalArticlepeer-review

Abstract

During the last glacial period, when sea level was low, meltwater discharge drove incision of the lower Mississippi valley, with valley filling and delta construction during Holocene sea-level rise. Isostatic modeling shows that sediment volumes removed and replaced were sufficient to induce uplift of >9 m along valley margins followed by subsidence of the same magnitude, with effects dissipating only over distances of >100-150 km along the Gulf of Mexico coast. Recognition of cyclical uplift and subsidence refutes recent interpretations of delta stability, and suggests that late Holocene relative sea-level curves from the delta region are instead a record of subsidence of the pre-Holocene depocenter. More broadly, incised valley cutting and filling is a common fluvial response to glacio-eustasy, and cyclical uplift and subsidence should be common to large alluvial-deltaic systems elsewhere.

Original languageEnglish (US)
Pages (from-to)675-678
Number of pages4
JournalGeology
Volume36
Issue number9
DOIs
StatePublished - 2008

Keywords

  • Holocene sea-level change
  • Incised valley
  • Isostatic uplift and subsidence
  • Mississippi delta

ASJC Scopus subject areas

  • Geology

Fingerprint Dive into the research topics of 'Ups and downs of the Mississippi delta'. Together they form a unique fingerprint.

Cite this