898 



EMILIANI AND FLINT 



[chap. 34 



Time-strati- 



grophic units 



(Zagwijn, 1957) 



(?) Elsterion 



Cromerian 



Menaplon 



Waalion 



Eburonian 



Tiglian 



Pre-Tiglian 



CLIMAT 



S.E. NETHERLANDS 



Fig. 1. Pleistocene temperature fluctuations inferred from pollen data. Left: Fluctuations 

 between late Pliocene and early middle Pleistocene time, estimated from pollen content 

 in strata in 8.E. Netherlands (Zagwijn, 1957, p. 240). Right: Fluctuations between 

 earliest (?) Pleistocene and middle Pleistocene time, estimated from pollen content 

 of two cores from points 500 m apart in a single lacustrine sequence near Leffe, Italy 

 (From an unpublished version, kindly furnished by Fausto Lona, of the curves in 

 Lona, 1950. p. 169; Lona and Follieri, 1957, p. 93.) 



The Leffe curves were fitted by R. F. Flint to the Netherlands curve by correlatmg 

 the temperature minima as suggested by Zagwijn (1957, p. 243), who first noticed the 

 similarities. The parts of the Leffe curves between those minima were fitted to the 

 intervening spaces by proportional reduction. Columnar sections show character of 

 sediments: black = peat and lignite; shading = inorganic sediments, chiefly marl and 

 clay. 



The vertical scale is not time calibrated in either curve; hence variations in local 

 rates of sedimentation are not compensated for. The troughs and peaks are significant 

 for relative amplitude only. 



succession of fluctuations, but as neither column is time-calibrated, spacing of the 

 peaks and troughs of the curves is dependent on rate of sedimentation at each 

 locality, so that curve slopes cannot be compared. 



Besides these three sequences there are two paleobotanical sequences in 



