Translator Disclaimer
1 May 2014 Evidence for Changes in Paleoenvironments along the Lower Cap-Rouge River, Québec (Canada), in Relation to a High Water Stand during the Mid-Holocene Laurentian Transgression
Jean-François Verville, Louise Filion, Patrick Lajeunesse
Author Affiliations +
Abstract

Verville, J.-F.; Filion, L., and Lajeunesse, P., 2014. Evidence for changes in paleoenvironments along the lower Cap–Rouge River, Québec (Canada), in relation to a high water stand during the mid-Holocene Laurentian transgression.

At the outlet of the Cap-Rouge River, upstream of the Québec sound on the St. Lawrence north shore, a 5-m-high stratigraphic section was excavated within an urban area, specifically, in a schoolyard located on the 14 m terrace on the east side of the river. Our stratigraphic and high-resolution macrofossil data show that major paleoenvironmental changes occurred along the lower Cap-Rouge River during the mid-Holocene. Macrofossil assemblages indicate that during a low water stand between 6320 and 6230 cal YBP, eastern hemlock (Tsuga canadensis [L.] Carr.) and white pine (Pinus strobus L.) formed mixed stands on the sandy terraces flanking the river. They also indicate that these mesophytic forests shifted to hydrophytic plant communities (eastern larch and aquatic plants) ca. 6230 cal YBP. These rapid changes in plant communities occurred during a mid-Holocene high water stand. Whether waters flowing at the Cap-Rouge River's outlet were brackish or soft waters during this highstand cannot be determined with certainty in absence of halophytes in the macrofossil records. Similar paleoenvironmental changes in plant cover have been well documented at several locations on the south shore of the St. Lawrence Estuary, where they were attributed to a rise in sea level coinciding with the Laurentian transgression. We also discuss the possibility that ice jams played a role in fluvial inundation and sedimentation over the last centuries at the mouth of several tributaries of the St. Lawrence River.

Jean-François Verville, Louise Filion, and Patrick Lajeunesse "Evidence for Changes in Paleoenvironments along the Lower Cap-Rouge River, Québec (Canada), in Relation to a High Water Stand during the Mid-Holocene Laurentian Transgression," Journal of Coastal Research 30(3), 465-473, (1 May 2014). https://doi.org/10.2112/JCOASTRES-D-13-00039.1
Received: 15 February 2013; Accepted: 13 May 2013; Published: 1 May 2014
JOURNAL ARTICLE
9 PAGES


Share
SHARE
KEYWORDS
Cap-Rouge River
mid-Holocene
Paleoenvironments
plant macrofossils
Québec
relative sea-level changes
St. Lawrence River
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top