CHAP. 34] THE PLEISTOCENE KECORD 913 



Ericson et al, 1961; Ewing et al, 1958; Parker, 1958; Phleger, 1939, 1942, 1947, 

 1948, 1951, 1955; Phleger and Hamilton, 1946; Phleger et al, 1953; Schott, 

 1935, 1952, 1954; Todd, 1958) revealed the occurrence of alternating warmer 

 and colder stages numbering up to nine or ten each in the stratigraphically 

 longest cores. Whenever the climatic record offered by the micropaleontology 

 is of sufficient detail, correlations can be made or attempted among the various 

 cores and between the core stages and the continental-Pleistocene stages. In 

 some cores, the correlations based on changing foraminiferal abundances have 

 been substantiated by correlations based on the changing ratio of left-to-right 

 coiled specimens of Globorotalia truncatulinoides (Ericson and Wollin, 1956; see 

 also Chapter 31). 



Oxygen-isotopic analysis of deep-sea cores from the Atlantic, the Caribbean 

 and the Mediterranean have yielded temperature records which correlate closely 

 with each other, as shown in Fig. 5 (cf. Emiliani, 1955, 1955a, 1958; Rosholt 

 et al., 1961, 1962), and also with the microjDaleontology (Ericson and Wollin, 

 1956a; Emiliani, 1957). A typical temperature graph (Fig. 6) shows a number 

 of warm units (identified by increasing odd integers in order of increasing 

 age) alternating with a number of cold units (identified by increasing even 

 integers in order of increasing age). One warm unit (no. 3) does not attain a 

 temperature as high as the other warm units, and two cold units (nos. 8 and 

 12) do not attain temperatures as low as the other cold units. One can thus dis- 

 tinguish major and minor warm and cold units. Within any given region, all 

 major warm units reach about the same temperature extremes, and so do all 

 major cold units. The measured temperature difference between major maxima 

 and minima in cores from low latitudes is about 8° or 9°C, but a correction 

 accounting for the greater concentration of i^O in sea- water during glacial ages 

 reduces this difference to about 6° or 7°C. An average, uncorrected temperature 

 difference of about 12°C is shown by Mediterranean core 189 (Emiliani, 1955a), 

 whereas a difference in surface temperatures of only about 4°C may be inferred 

 from oxygen-isotopic analyses on Globorotalia menardii tumida from cores raised 

 in the eastern equatorial Pacific (Emiliani, 1955). Thus it appears that, as ex- 

 pected, temperature oscillations of the surface waters of the oceans during 

 the Pleistocene were smallest in the equatorial Pacific, were larger at corres- 

 ponding latitudes in the Atlantic, and were still larger in the more northern 

 Mediterranean basin. 



Arrhenius (1952) and Olausson (1960a, 1961) published chemical ana- 

 lyses on a number of Pacific cores and included data on the micropaleontology 

 and other features of the sediments. As previously mentioned, carbonate per- 

 centages were found to vary markedly and repeatedly in a suite of five cores 

 from the eastern equatorial Pacific, possibly reflecting productivity changes 

 associated with major climatic fluctuations. Correlation among these cores was 

 made using the cumulative amounts of TiO-a in the sediments, and the last four 

 major carbonate maxima were correlated with the four major glaciations 

 (Arrhenius, 1952). If this correlation is correct, the occurrence of earlier car- 

 bonate maxima in two of the cores (nos. 58 and 62) would suggest that 



