Agassiz, Lake(ăg`əsē), glacial lake of the Pleistocene epochPleistocene epoch
, 6th epoch of the Cenozoic era of geologic time (see Geologic Timescale, table). According to a classification that considered its deposits to have been formed by the biblical great flood, the epoch was originally called the Quaternary.
..... Click the link for more information. , c.700 mi (1,130 km) long, 250 mi (400 km) wide, formed by the melting of the continental ice sheet beginning some 14,000 years ago; it eventually covered much of present-day NW Minnesota, NE North Dakota, S Manitoba, central E Saskatchewan, and SW Ontario. The lake was named in 1879 in memory of Louis AgassizAgassiz, Louis
(Jean Louis Rodolphe Agassiz) , 1807–73, Swiss-American zoologist and geologist, b. Môtiers-en-Vuly, Switzerland. He studied at the universities of Zürich, Erlangen (Ph.D., 1829), Heidelberg, and Munich (M.D., 1830).
..... Click the link for more information. for his contributions to the theory of the glacial epoch. Lake Traverse, Big Stone Lake, and the Minnesota River are in the channel of prehistoric River Warren, Lake Agassiz's original outlet to the south. As the ice melted, the water drained E into Lake Superior, and after the ice disappeared, N into Hudson Bay. The lake's disappearance (c.8,400 years ago) left lakes Winnipeg, Manitoba, and Winnipegosis, Red Lake, Lake of the Woods, and other smaller lakes. The bed of the old lake, the Red River valley, has become an important crop-growing region due to its rich soil.