Mineral and grain-size partitioning in a glacial to marine transect, western Baffin Bay, Canada
Pleistocene and neoglacial tills on the Precambrian shield of Baffin Island are sandy gravels with <10% in the silt/clay fraction. Observations indicate that large amounts of sediments are being carried in suspension by glacial melt water streams. Silts and clays are transported into the proximal marine environment largely as overflows where they flocculate and settle. Mineralogical analysis of the clay and silt-size fraction of one fiord core (SU5) and one shelf core (HU78-37) from western Baffin Bay were completed to investigate mineral partitioning of transport from land to sea. Such studies are commonly conducted on the clay-sized particles, but there are few investigations of the silt-sized fraction, even though silts often make up more than 50% of these marine sediments. X-ray diffraction analyses of two cores show significant differences in mineralogy. Relative to the average composition of the Precambrian shield rocks of Baffin Island the clay-size mineralogy reflects a significant enhancement in mica and depletions in quartz and feldspar. The same trend is observed in the silt-sized mineralogy, where enrichment in mica is still significant, however, the mineralogy of the two size fractions differs markedly. The overall change in mineralogy from the clay-sized to silt-sized particles shows a decrease in mica, kaolinite and chlorite and a significant increase in dolomite and calcite, which are foreign to the area. These results, combined with ongoing studies on sand-sized mineralogy will enable a sediment budget approach to glacial erosion/deposition.
- Research Organization:
- Univ. of Colorado, Boulder (USA)
- OSTI ID:
- 6576955
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Vol. 17; ISSN GAAPB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
CANADA
CENOZOIC ERA
CHALCOGENIDES
COHERENT SCATTERING
CONTINENTAL MARGIN
CONTINENTAL SHELF
DEPOSITION
DIFFRACTION
EROSION
FELDSPARS
GEOLOGIC AGES
GEOLOGY
GLACIERS
KAOLINITE
MICA
MINERALOGY
MINERALS
NORTH AMERICA
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLEISTOCENE EPOCH
QUARTZ
QUATERNARY PERIOD
SAND
SCATTERING
SEDIMENTS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
SILT
STRATIGRAPHY
X-RAY DIFFRACTION