Publication information

Geological Survey of Canada
Open File 8851

Thickness record of varves from glacial Ojibway Lake recovered in sediment cores from Frederick House Lake, northeastern Ontario

G.R. Brooks

© Her Majesty the Queen in Right of Canada, as represented by the Minister of Natural Resources, 2022

Permanent link: https://doi.org/10.4095/329275

Publications in this series have not been edited; they are released as submitted by the author.

Recommended citation

Brooks, G.R., 2022. Thickness record of varves from glacial Ojibway Lake recovered in sediment cores from Frederick House Lake, northeastern Ontario; Geological Survey of Canada, Open File 8851, 
1 .zip file. https://doi.org/10.4095/329275

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Contents

The thicknesses of 384 rhythmic couplets were measured along a composite sequence of glacial Lake Ojibway glaciolacustrine deposits recovered in two sediment cores from Frederick House Lake, Ontario.  The visual comparison of distinctive couplets in the CT-scan radiographs of the Frederick House core samples to photographs of core samples from Reid Lake show a match of ±1 varve number from v1656-v1902, and ±5 varve numbers between v1903-v2010, relative to the regional numbering of the Timiskaming varve series.  There are two interpretations for the post-v2010 couplets that fall within the Connaught varve sequence of the regional series.  In the first, the interpreted numbering spans from v2066-v2115, which produces a gap of 55 missing varves equivalent to v2011-v2065, and corresponds to the original interpretation of the Connaught varve numbering.  The second spans v2011a-v2060a, and represents alternative (a) numbering for the same varves.  Varve thickness data are listed in spreadsheet files (.xlsx and .csv formats), and CT-Scan radiograph images of core samples are laid out on a mosaic poster showing the interpreted varve numbering and between-core sample correlations of the varve couplets.

Directory structure

of_8851_readme.rtf (this file)
of_8851.pdf (report)
of_8851_AppendixA – One folder containing spreadsheets in .xlsx and .csv formats listing the measured thicknesses of 384 rhythmic couplets that form the Frederick House Lake varve series.
of_8851_AppendixB – One folder containing a poster-sized figure in pdf format depicting the radiograph images of the two cores recovered from Frederick House Lake. The core radiographs are arranged vertically in relative stratigraphic position.  

Author contact information

G.R. Brooks (greg.brooks@nrcan-rncan.gc.ca)
Geological Survey of Canada
601 Booth Street
Ottawa, Ontario
K1A 0E8

Availability information

This publication is available for free download through GEOSCAN (https://geoscan.nrcan.gc.ca/).

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