Paleoecology of an arctic estuary
ABSTRACT. An alternating sequence of black silt and clay units, and coarse sand and gravel units, has been found to depths of 30 ft. below sea level in the sediments underlying an arctic estuary. The black silt and clay units, containing pitted foraminiferal tests, were deposited in an anaerobic env...
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| Format: | Text |
| Language: | English |
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1966
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.598.5137 http://pubs.aina.ucalgary.ca/arctic/arctic19-4-343.pdf |
| Summary: | ABSTRACT. An alternating sequence of black silt and clay units, and coarse sand and gravel units, has been found to depths of 30 ft. below sea level in the sediments underlying an arctic estuary. The black silt and clay units, containing pitted foraminiferal tests, were deposited in an anaerobic environment while the estuary was isolated from the ocean by a gravel bar across its mouth. The sand and gravel units, containing pelecypod fragments, resulted from the destruction and spreading of the gravel bar inland under marine conditions. A radiocarbon date at the base of the sequence indicates these conditions first occurred 6,450 years ago. Rl?,SUMl?,. Paltotcologie d’un estuaire arctique. On a trouve, dans les sediments tapissant un estuaire arctique, une sCquence alternee d’horizons de limon noir et d’argile et d’horizons de sable grossier et de gravier, s’Ctageant jusqu’à une profondeur de 30 pieds (9.14 m.) sous le niveau de la mer. Le limon et l’argile contiennent des tests de foraminifches et se sont dCposks en milieu anaerobic, au moment ou une flèche de gravier accumulCe en travers de l’embouchure isolait l’estuaire de I’ocCan. Le sable et le gravier contiennent des fragments de pClCcypodes et rksultent de la destruction et de l’etalement de cette fltche en milieu marin. Une datation au radiocarbone, au bas de la sCquence, indique que ces conditions sont apparues il y a 6,450 ans. |
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