Paleoceanography and glacial runoff along the St. Lawrence valley system

Conference · Wed Jan 01 00:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5808737

Rodrigues, C G ^[1]; Vilks, G ^[2]

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1. Univ. of Windsor, Windsor, Ontario (Canada). Dept. of Geology
2. Bedford Inst. of Oceanography, Dartmouth, NS (United States)

Radiocarbon-dated foraminiferal zones in cores from the Gulf of St. Lawrence show that cold saline bottom-water was present in the Goldthwait Sea between 13.6 and 12.9 ka BP and was followed by a salinity minimum from ca. 12.1 to 8.6 ka BP, and then increasing salinity and temperature resulting in the modern, deep, watermass layer by 8 ka BP. During the salinity minimum, glacial Lake St. Lawrence drained east into the Goldthwait Sea before the beginning of the Champlain Sea (11.6--11.4 ka BP). Meltwater flowed through the Champlain and Goldthwait seas between 11 and 10 ka BP when Lake Agassiz water was diverted to the North Atlantic Ocean through Ottawa and St. Lawrence valleys and Gulf of St. Lawrence; this coincides with the decrease in salinity of the Champlain Sea between 10.7 and 10.4 ka BP. A later discharge of meltwater to the North Atlantic Ocean (9.5--8 ka BP) occurred during the final stage of the salinity minimum in the Goldthwait Sea and postdates or coincides with the end of the Champlain Sea. The discharge of meltwater to the North Atlantic Ocean may have cause the freshening of the Champlain Sea. However, it does not appear to have affected the deep water in the Goldthwait Sea and was probably part of the surface outflow to the North Atlantic Ocean through the Gulf of St. Lawrence. The variations in salinity of the deep water of the Goldthwait Sea are related to changes in the composition of the water entering the sea from the North Atlantic Ocean.

• OSTI ID: 5808737
• Report Number(s): CONF-921058-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
GLACIERS
RUNOFF
ST LAWRENCE RIVER
DRAINAGE
AGE ESTIMATION
ATLANTIC OCEAN
CARBON 14
FORAMINIFERA
GEOLOGIC HISTORY
ISOTOPE DATING
OCEANOGRAPHY
SALINITY
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON ISOTOPES
ENVIRONMENTAL TRANSPORT
EVEN-EVEN NUCLEI
INVERTEBRATES
ISOTOPES
LIGHT NUCLEI
MASS TRANSFER
MICROORGANISMS
NUCLEI
PROTOZOA
RADIOISOTOPES
RIVERS
SARCODINA
SEAS
STREAMS
SURFACE WATERS
YEARS LIVING RADIOISOTOPES
580000* - Geosciences