A lake sediment-based proxy of floods in the Rocky Mountain Front Ranges, Canada

Erik Schiefer, Robert Gilbert, Marwan A. Hassan

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

We analyzed lake sediment deposits and local hydrometric records to assess the potential for developing a high-resolution record of sediment delivery from the Rock Lake catchment, situated in the non-glacierized Front Ranges of the Rocky Mountains, Canada. Rhythmic couplets of silt-clay characterized the clastic sediments recovered from the deep central basin of the lake. Contemporary sediment yield to Rock Lake (10.7 ± 1.8 Mg km-2 year-1) is comparable to other studied Canadian Cordillera lakes that have sedimentary lithologies and absence of glacier cover, but distinct rhythmic deposition is relatively unique to this basin. Spatial patterns of deposition within the lake were assessed by correlating rhythmites between multiple sediment cores and by sub-bottom, acoustic profiling. Bracketed dates for a spatially continuous sequence of eight thick rhythmites were established by correlating laminations between core samples collected more than 30 years apart. We identified a consistent pattern between the rhythmite and hydrometric data series between 1975 and 2006 and determined that specific flooding events caused by summer rainstorms are associated with each of the eight thick rhythmites. We observed a good relationship between rhythmite thickness and total flood volume that exceeded a threshold discharge. Acoustic profiling showed that the lake could be a good candidate for longer-term proxy development. We discuss how some of the methods used in this study could benefit ongoing paleoenvironmental assessments based on lacustrine rhythmite series.

Original languageEnglish (US)
Pages (from-to)137-149
Number of pages13
JournalJournal of Paleolimnology
Volume45
Issue number2
DOIs
StatePublished - Jan 1 2011

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Keywords

  • Flood proxy
  • Lake sediment
  • Rhythmites
  • Rock Lake

ASJC Scopus subject areas

  • Aquatic Science
  • Earth-Surface Processes

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