108 Nature Vol. 279 10 May 1979 One or more Eemian interglacials? IN a recent paper (Nature 277, 189; there are other more probable can facies approach. 1979) we described the Fj0sanger didates (RUgen, Domnitz/Wacken) to Discrimination of specific inter (interglacial) Stage in western Nor fill the milder intervals (see Weigank glacials on the basis of either being way, and correlated it with deep sea op. cit.; Erd Palaeogeogr., -clim., covered by till or not in relation to oxygen isotope stage 5e and the -ecol. 8, 129; 1970; Frenzel Eiszeitalter postulated glacial limits is no im Eemian of continental Europe. Bowen alter u. Gegenw. 23/24, 321; 1973; provement on 'count from the top' (News & Views 277, 171; 1979) Menke & Behre Eiszeitalter u. methods criticised by Kukla. In this accepted the former correlation but Gegenw. 23/24, 251; 1973; Cepek Ber. way the current conventional wisdom, criticised the latter, because he agrees deut5ch. Ges. geol. Wiss., A. Geol. or model chronostratigraphic schema, wi.th Kukla's proposal (Earth Sci. Rev. Paliiont. 12, 375; 1967) than the is maintained. Data are not only in 13, 307, 1977) that the Eemian Eemian, even if Kukla's interpreta terpreted on such model terms but are represents three different interglacials. tion is correct. frequently acquired and systematised The vegetational development in The main evidence in support of according to its pigeon-holed ready different interglacials may have been our thesis that the typical Eemian made classification-the 'reinforce so similar that a separation on pollen sequence represents only one ment syndrome' of the late Norman palynological evidence is impossible. interglacial can be summarised as Watkins (Comments on Earth Sci. However, this is not necessarily so, follows. Many known Eemian sites Geophys. 2, 36; 1971). In the case of and the crucial point in the present are located inside the Weichselian ice Weigank's work the significant point discussion is whether other inter border; all of them are situated below re,Jates to his demonstration that the glacials repeated the distinct pollen till or disturbed by ice. More than 100 foraminiferal faunas of the Eemian sequence so far being considered as Eemian sites are known outside the and Rtigenian Interglacials show only the criterion for the Eemian. Weichselian ice border, and, as far as minor differences. We fully agree with Bowen's state we know, not a single sequence is re The fact is that, according to ment that the deep sea oxygen isotope ported to be below till, or below an present interpretation (Shackleton & stratigra.phy proves that the classical other interglacial. However. many Opdyke Quaternary Res. 3, 39; 1973) subdivisions of the Quaternary of 'not Eemian interglacials' are known and defining the base of the Middle Europe are incomplete. That is our b~low till outside the Weichselian ice Pleistocene at the Brunhes-Matuyama challenge! However, an incomplete border. boundary (Butzer Quaternary Res. 4, continental stratigraphy does not We conclude that our present 136; 1974), some eight interglacials imply that all previously defined units knowledge strongly suggests that the occurred from that time to the are ambiguous. Eemian pollen sequence of Europe present. It is pertinent to note that Bowen olaimed that Weigank represents only one interglacial. which one of the UK working parties on (Geologie 21, Beiheft 77, I; 1972) has is the Last Interglacial. International Geological Correlation described two Eemian interglacials in JAN MANGERUD Programme Project 24 is examining superposition in northern Germany. EIVIND S0NSTEOAARD evidence to determine how many in On the contrary, however, he stated HANS-PETTER SEJRUP terglacials there have been since the that these two interglacials can be Department of Geology, Hoxnian. Conventionally there is identified on the basis of their pollen Allegt. 41, only one-the Tpswichian (Eemian)! stratigraphy, the younger being the 5014 Bergen-U niversitetet, In the search for greater com Eemian, and the older the Rtigenian Norway. plexity in cor.• ment,al records it is ( = Kap Arkona in Frenzel's classifica inevitable that some degree of data tion). manipulation will occur initially be Most important Bowen stated that D. Q. BOWEN REPLIES: The points cause many of the basic facts regard Kukla (op. cit.) has demonstrated that raised by Mangerud et a/. are only ing Pleistocene geology are still in the classical Eemian sites in Europe valid in so far as the chronostra adequately known. For too long has it were deposited during three different tigraphy advocated by Kukla and been assumed that the Pleistocene interglacials. No doubt, Kukla made others is incapable of direct validation geology of most formerly glaciated an extremely interesting analysis of at present. But the fact remains that areas is known-perhaps it is, at least the Quaternary stratigraphy of the system they advocate and defend according to the terms of existing Et~rope, but we cannot accept his in the case of 'Eemian' is based on models. But in terms of modern litho evidence for more than one Eemian. assemblage floras, a biofacies basis stratigraphic standards (Hedberg Int. Chiefly on the basis of geomorpho inherently unreliable as a result of its Stratigraphic Guide, New York, 1976) logical observations he postulated diachronous nature. Indeed by advo this work. with some notable ex that the Saalian s.l. is composed of cating that Woillard's (Quaternary ceptions (Willman & Frye Illinois three distinct glacials, and he used Res. 9, I; 1978) St Ge.rmain Inter Geol. Surv. Bull. 94, 1970), has hardly Eemian sites for the presumptive glacials, I and IT, are time-equivalent commenced. In the meantime, other interglacials so created. Most West to interstadials in the Netherlands than by rare geochronometric dating, German geologists (Duphorn et a/. and Denmark, also urged by Wijmstra progress will inevitably include some Eiszeitalter u. Gegenw. 23/24, 222; (in Climatic Change (ed. Gribbin) manipulation born out of an ex 1973) reject the existence of an inter Cambridge, 1978), they tacitly ac pediency dealing with inadequate glacial within the Saalian s.l., but knowledge the fragility of this bio- data.
some time. The public mind both in who know something on the subject A hundred years ago this countrv and abroad has been must find it difficult to make up their WE need not insist on the extreme im recently mtich agitated on the ques minds. Hence the importance of bring portance and interest of the exhibition tion of electric lighting, and. as might ing together the various systems of which was opened last night at the be expected. people are much confused electric lighting in such a way as to Albert Hall, and for which extensive among the many systems which have make comparison possible. preparations have been making for been brought forward, and even those From Nature 20, 8 May, 39; 1879.
0028--C836/79/0279----0108SOJ .CO C Macmillan Journals Ltd 1979