High-resolution multiproxy records of sedimentological changes induced by dams in the Sept-Îles area (Gulf of St. Lawrence, Canada)
| Autor: | Ursule Boyer-Villemaire, Jacques Labrie, Patrick Lajeunesse, Guillaume St-Onge, Pascal Bernatchez |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
010504 meteorology & atmospheric sciences
Flood myth Sediment High resolution Climate change Geology 010502 geochemistry & geophysics Oceanography 01 natural sciences Coring Paleontology Geochemistry and Petrology Sedimentary rock Submarine pipeline Geomorphology 0105 earth and related environmental sciences Chronology |
| Zdroj: | Marine Geology. 338:17-29 |
| ISSN: | 0025-3227 |
| DOI: | 10.1016/j.margeo.2012.11.012 |
| Popis: | A multiproxy approach was performed on two sediment box cores sampled in the NW Gulf of St. Lawrence in order to better understand the impacts of recent climatic or land-use changes on the sedimentary regime in the proximal offshore zone. Multibeam and seismic surveys allowed for the careful selection of coring sites. The chronology of the cores was established by 210 Pb measurements and validated with coinciding historical weather events recorded in both cores, confirming that the sediments are recent (last 370 years). The lithological variations in the cores were quantified using 1) stratigraphic markers and grain size measurements, 2) high-resolution X-ray micro-fluorescence (XRF), and 3) physical and magnetic tracers. The grain size measurements allowed the identification of a major flood around AD 1844 ± 4 years, whereas a drastic decrease in variations and in the median grain size (d50) occurred around AD ~ 1900, highlighting the offshore impact of the SM1 dam construction on the Sainte-Marguerite River in the early 1900s. Sedimentological variations have been investigated by wavelet analysis using XRF data and the sharp disappearance of high frequencies ( |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect