Geologic and Archæologic Time -- By: Warren Upham
BSac 72:286 (April 1915) p. 421
Geologic and Archæologic Time
Recent researches and publications by two eminent glacialists of Sweden, Dr. Nils Olof Holst and Baron Gerard De Geer, present estimates and measurements of the” Postglacial period in northern Europe quite nearly like the estimates earlier published by Professors N. H. Winchell, G. F. Wright, and the present writer, for this latest period of geology in America. Because many other geologists, however, hold widely different views of the duration of time since the Ice Age, magnifying it several times beyond the 5,000 to 10, 000 years ascribed to it by these glacialists, we may profitably review for general readers the evidences on this question for both the European and the North American ice-sheets.
In a memoir by Hoist, published in 1909 by the Geological Survey of Sweden (Series C, No. 216, pages 74), on the length of the Postglacial period, he argues, from his lifelong work on the glacial geology and archæology of Sweden, and from the work of his associates in that country, that the time since the ice-sheet was melted away in Scania, the southmost district of Sweden, has been 6, 900 years; and that the earliest trace of primitive man in Scandinavia, belonging to a Neolithic culture stage, was 6, 150 years ago. This first advent of
BSac 72:286 (April 1915) p. 422
man in the south end of the peninsula was during the middle part of the existence of the Ancylus lake, as the Baltic sea (with the gulfs of Bothnia and Finland) is called for the time while the earth movements attending the departure of the ice-sheet raised the present mouth of that sea, between Sweden and Denmark, above the sea level. The Baltic basin then held for some time, estimated by Hoist as 1, 675 years, a vast fresh-water lake, known by its shells of Ancylus fluviatilis, with an outlet in southern Sweden on the latitude of the present lakes Vetter and Vener, where the Gota canal crosses the peninsula watershed, 300 feet above the present Baltic sea and the ocean.
Previous to this Ancylus lake, the Baltic basin and all this peninsula had stood lower than now, during the early part of the final melting of the ice-sheet, so that the earliest Postglacial (or more correctly Late Glacial) sea beaches and other marine deposits of that time have been since uplifted (with all the land area and sea bed) to altitudes that increase from near the sea level in eastern and northern Denmark and in Scania to several hundred feet about Stockholm and northward: Arctic marine shells, species of Yoldia and other genera, in these deposits, give the name Yoldia Sea to the waters then laving Sweden and Norway.
The depression of this large tract of the earth crust, recorded by the Yoldia clays, se...
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