DOI: 10.5061/dryad.8cz8w9gpw
title: A 520-year paleolimnological grain size and ITRAX record from Harvey Lake, New Brunswick, Canada

description: This grain size data was derived from a 250 mm long gravity Glew Maxi core
 (HL-2017-GC-2) collected from near the mouth of Herbert's Cove,
 Harvey Lake, New Brunswick Canada (45°43’42.535” N; 67°01’23.739” W) at a
 water depth of 4.5 m.  The core was subsampled on-site at 2 mm
 resolution using a Glew core extruder before transport to Carleton
 University for subsequent analysis. Subsamples were analyzed using a
 Beckman Coulter LS 13 320 laser diffraction grain size analyzer equipped
 with a universal liquid module.  The resultant triplicate grain
 size data were averaged using a script within Matlab which generated the
 data archived here.  The data was then analyzed using End Member
 Mixing Analysis and three distinct end members were recognized EM01, Mode
 = 05 μm; EM02, Mode = 27μm; EM03, Mode = 58 μm). Subsequent radiocarbon
 dating revealed that deposition spanned the last 520 years of deposition.
 During this interval there were 12 major storms (EM03) and analysis of
 precipitation data from the Harvey climate station indicated that ~110 mm
 of rain was required for the deposition of EM01 in Harvey Lake. The
 deposition of EM02 was derived from the yearly spring freshet runoff.
description: In preparation for grain-size analysis, 118 sediment subsamples
 from core HL-2017-GC-2, collected in July 2017, from 4.5 m water depth
 were processed at mm-stratigraphic resolution. 30%
 H<sub>2</sub>O<sub>2</sub> was added to subsamples
 and then placed in an 80<sup>o</sup>C water bath to oxidize
 organic matter. Analysis of randomly selected samples treated using 10%
 HCl indicated that sediment carbonate content was insignificant so an HCl
 pretreatment was deemed unnecessary and not used. Following the
 H<sub>2</sub>O<sub>2</sub> pretreatment,
 subsamples were analyzed using a Beckman Coulter LS 13 320 laser
 diffraction grain size analyzer equipped with a universal liquid module.
 Subsamples were hand agitated to suspend the sediments and then pipetted
 into the analyzer until an obscuration of 10±3% was achieved. This slurry
 was then circulated within the module for sixty seconds prior to the first
 of three replicate runs. Each sample was analyzed in triplicate resulting
 in grain size distributions potentially ranging from 0.4-1500 µm. The
 triplicate analyses were averaged for each sample and Gradistat v8 was
 subsequently used to generate summary statistics for the grain-size
 distribution data.  The grainsize data were used as inputs for subsequent
 End Member Mixing Analysis (EMMA) where three recognized end members
 (EM01, Mode = 05 μm; EM02, Mode = 27μm; EM03, Mode = 58 μm) were derived
 from particle size data. ITRAX XRF results characterizing Glew Core 2
 (2017.HC.HL.GC-2) from Herberts Cove, Harvey Lake were also measured for
 each subsample horizon. The Bacon age model estimated dates of deposition
 for each analyzed horizon are also presented, and those associated with
 major storms (EMO3) are shaded gray. Due to age model uncertainties there
 may be errors associated with the derived dates.  Rainfall totals during
 the open water season (April-November), where &gt;75 mm fell during
 single or multi-day events, were recorded from three sequential Government
 of Canada Climate Stations positioned in Harvey Station Station, New
 Brunswick spanning from 1920-2004. Lesser amounts associated with
 hurricane remnants known to have tracked across the area are also
 included.
description: There were some sampling gaps in the core at 0, 96, 170, 186,
 190, 192, 212, 214 mm.