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TitleLate Quaternary changes in sediment sources in the Labrador Sea
AuthorAndrews, J TORCID logo; Piper, D J WORCID logo
SourceCanadian Journal of Earth Sciences vol. 60, 2022 p. 189-213,
Alt SeriesNatural Resources Canada, Contribution Series 20220193
PublisherCanadian Science Publishing
Mediapaper; digital; on-line
File formatpdf
ProvinceNewfoundland and Labrador; Northwest Territories
NTS26; 16; 25; 15; 24; 14; 23; 13; 3; 22; 12; 2; 21; 11; 1
AreaBaffin Island; Greenland
Lat/Long WENS -70.0000 -35.0000 70.0000 45.0000
Subjectsmineralogy; sedimentology; sediments; detrital minerals; carbonate; carbonates; marine sediments; glacial deposits; x-ray diffraction; statistical analysis; Baffin Bay Basin; Davis Strait; Labrador Sea; Quaternary
Illustrationslocation maps; tables; diagrams; plots; pie charts; bar graphs
ProgramMarine Geoscience for Marine Spatial Planning
Released2022 09 15
AbstractQuaternary sediment in the Labrador Sea was derived from many proglacial sources in Greenland and eastern Canada. Understanding the spatial and temporal changes in sediment provenance provides information on ice extent and sediment dispersal patterns. Variations in mineral composition of sediment from late Quaternary cores has been determined by a whole pattern of quantitative X-ray diffraction procedure. Mineral facies were extracted statistically by a supervised analysis of 90 samples from bedrock and ice-rafted clasts, which were then used to predict the most probable mineral facies in 1443 marine sediment samples. We used a non-parametric Classification Decision Tree (CDT) to validate that decision. Only 26% of the samples weremisclassified in the CDT. The six facies identified consisted of four facies reflecting differences in the composition of Canadian and Greenland Precambrian igneous and metamorphic bedrock, a set of samples dominated by high weight percentages of calcite and dolomite (detrital carbonate (DC) and Hudson Strait Heinrich (HS-H) events), and a “shale” facies. We isolated 284 sediments from the HS-H DC facies and determined that they could be divided into four categories based on differences in their mineral proportions. These categories vary geographically, based on non-carbonate sediment supply during these events from Greenland, the Canadian Shield, the Appalachians, and the outer continental shelf. In the Holocene of the Labrador Sea, dolomite is derived from Baffin Bay and abundance of calcite is influenced by both biogenic productivity and dissolution.
Summary(Plain Language Summary, not published)
We present the first comprehensive data set on variation in mineral composition of glacial and post-glacial sediments in the Labrador Sea. Statistical analysis of mineral composition is used to track changes in sediment sources and dispersal patterns through time.

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