902 EMILIANI AND FLINT [CHAP. 34 



missing in the region studied by Pfannenstiel, but sea-level may have risen to 

 + 3-4 m about 5000 years ago. Such a high stand of the sea-level in the recent 

 past has been recognized by some authors (Fairbridge, 1958; Hopkins, 1959; 

 Schofield, 1960) but not by others (Shepard and Suess, 1956; Godwin et al., 

 1958; Graul, 1959; Jelgersma and Pannekoek, 1960). 



Sea-level rise during the last 15,000 years can be seen also in the stratigraphy 

 of the Mississippi delta (Fisk and McFarlan, 1955; McFarlan, 1961), but the 

 situation is complicated by the large amount of subsidence and sediment com- 

 paction that has occurred (cf. Broecker, 1961). 



During the Pleistocene, the Po Valley was filled with marine sediments 

 grading into continental ones upwards and landwards. In limited areas the 

 combined marine and continental Pleistocene sediments attain the remarkable 

 thickness of 2000 m (Perconig, 1956). Preliminary work by Selli (1949), Perconig 

 (1956), Ruggieri and Selli (1950), and others has revealed the repeated occurrence 

 of warm and cold stages. Through most of the Po Valley there is continuity of 

 sedimentation between Pliocene and Pleistocene, the boundary being recog- 

 nized on the basis of Foraminifera (Perconig, 1956). 



Classical Plio-Pleistocene sections of marine epicontinental deposits occur in 

 Calabria, southern Italy. It was in this area that Gignoux (1913) established the 

 Calabrian stage, the base of which is accepted by many as marking the beginning 

 of the Pleistocene Epoch (Intern. Geol. Cong., 1950). In many sections there is 

 continuity of sedimentation between Pliocene and Pleistocene, and the boun- 

 dary is identified by the sudden appearance of northern species of marine 

 mollusks and Foraminifera (esp. Cyprina islandica and Anomalina haltica). 

 Oxygen-isotopic analyses of shells of pelagic Foraminifera collected at close 

 stratigraphic intervals from the section at Le Castella, near Crotone, has re- 

 vealed the occurrence of marked temperature oscillations, present in the 

 Pliocene but becoming especially large in the Pleistocene (Emiliani et al., 1961). 

 In addition, a progressive decrease of the secular maxima and minima was 

 observed, but no sudden, large temperature decrease was noticed across the 

 sharply defined paleontological boundary. Important temperature changes 

 were observed to take place across stratigraphic intervals as short as a meter or 

 two, suggesting that, because of rapidly changing conditions during the Pleisto- 

 cene, marine-epicontinental deposits of Pleistocene age should be sampled in 

 far greater stratigraphic detail than has generally been done. 



Excellent sections of marine-epicontinental sediments exist in East Anglia 

 and the Netherlands. In parts of the Netherlands, marine Pleistocene sediments 

 follow conformably marine Pliocene sediments. The boundary, recognized from 

 the gradual advent of foraminiferal faunas adjusted to cooler conditions, lies as 

 deep as 600 m below sea-level in the area of Haarlem (Pannekoek, 1954, 1956). 

 The foraminiferal faunas have been described in detail by ten Dam and Rhein- 

 hold (1942), Pannekoek and van Voorthuysen (1950), van Voorthuysen (1950, 

 1953), and others. The marine Pleistocene deposits pass upwards and eastwards 

 into estuarine facies, making it difficult to recognize temperature variations 

 other than the cooling that marks the beginning of the Pleistocene. 



