The distribution of brick red lutite in the western North Atlantic

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6069461

Barranco, Jr, F T; Balsam, W L

One method used to analyze deep water circulation is to track the path of a unique sediment type input from a point source. A well known point source sediment is the late glacial brick red lutite of the western North Atlantic. Eroded from Carboniferous red beds in the Canadian maritime provinces, red detritus was transported out the Cabot Straits and redistributed to the south and west along the continental margin by the Western Boundary Undercurrent (WBUC). In this paper the authors use visible light spectra (400-700 nm) to characterize the temporal and spatial distribution of brick red lutite in 14 cores off eastern North America. Brick red lutite exhibits increased red reflectance due to an enrichment in Fe/sup 3+/ (4-7%) residing in the mineral hematite. Analysis of the red portion of the visible light spectrum (630-700 nm) has improved identification of the areal extend of red lutite compared to previous studies involving color chart analysis. Spectral values verify that little red sediment is transported out the Gulf of St. Lawrence today, even though measurements have been increasing over the last 6,000 yr. Modern values along the North American continental margin are just slightly higher than the oceanwide average for red reflectance and are similar to other continental margins. During late glacial time spectra in cores from the Cabot Straits are similar to those derived from pure hematite. Glacial age sediments with high red reflectance are also present on the Laurentian Fan and to the southwest along the North American continental margin. These values fall off both downstream and upslope indicating the path of the WBUC and downcurrent dilution.

• OSTI ID: 6069461
• Report Number(s): CONF-880301-
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580500* -- Oceanography-- (1980-1989)
ATLANTIC OCEAN
CHALCOGENIDES
CONTINENTAL MARGIN
DISTRIBUTION
EXPLORATION
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOPHYSICS
HEMATITE
IRON COMPOUNDS
IRON ORES
IRON OXIDES
MINERAL RESOURCES
MINERALS
MISSISSIPPIAN PERIOD
NATURAL GAS DEPOSITS
OPTICAL PROPERTIES
ORES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PALEOZOIC ERA
PENNSYLVANIAN PERIOD
PETROLEUM DEPOSITS
PHYSICAL PROPERTIES
RESOURCES
SEAS
SEDIMENTS
SOURCE ROCKS
SPATIAL DISTRIBUTION
SPECTRA
SURFACE WATERS
TRANSITION ELEMENT COMPOUNDS
VISIBLE SPECTRA