
Thickness record of varves from glacial Ojibway Lake recovered in sediment cores from Frederick House Lake, northeastern Ontario
Author(s) -
Greg Brooks
Publication year - 2022
Language(s) - English
Resource type - Reports
DOI - 10.4095/329275
Subject(s) - varve , geology , glacial period , numbering , sequence (biology) , sediment , paleontology , algorithm , chemistry , computer science , biochemistry
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-scanradiographs 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 forthe 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 varvenumbering. 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 varvenumbering and between-core sample correlations of the varve couplets.