Eustatic changes during the last 20,000 years and a method of separating the isostatic and eustatic factors in an uplifted area
Abstract The present paper (presented at the VIII INQUA Congress in Paris 1969) deals with the eustatic changes since the maximum lowering of the ocean level during the glaciation maximum about 18,000 B.C. (20,000 B.P.). The eustatic curve is believed also to depict the climatic changes quite closely. For the period 11,750 B.C.– 200 B.C., the eustatic curve is derived from southern Scandinavia by a calculation of the eustatic and isostatic factors, respectively, in shorelevel displacement curves from several points in the direction of tilting from strongly uplifted to slightly subsided isobase latitudes ( Morner 1969a). The eustatic curve obtained is highly fluctuating, though with a small amplitude. The present position was reached 1,700-1,400 B.C. (PTM-7 at + 0.4 m). With information from Vendsyssel (in comparison with other parts of the Kattegatt area), the Gulf of Mexico and the shelf off northeast America (excluding the isostatic factor) the eustatic curve was extended back in time to the glaciation maximum about 18,000 B.C., where a eustatic sea level of about — 85–90 m was found. At about 13,000–12,800 B.C. a 10 m drop in sea level was found, corresponding to the second glaciation maximum during the Late Wurm-Weichsel-Wisconsin.