德国Palatinat北部爱森贝格盆地早第三纪孢粉组合时代的确定

艾森贝格盆地（Eisenberg Basin)位于梅因茨盆地（Mainz Basin)西南部,为莱茵地堑的一部分,因为化石稀少,这里的地层和梅因茨盆地典型的第三纪地层很难对比,因此,它们的地质时代长期处于争论中。对于Lautersheim 1钻孔及Lautersheim附近地层露头的孢粉地层学研究表明,这一地区的第三纪可以三分,Lautersheim 1钻孔的下部属于中始新统,相当于Krutzsch的SPP 15／16带,该钻吉中部的一部分可置入早渐新世,相当于SPP19带;这部分可以再分为上下两部分;下部含大量始新世微体植物化石,而上部此类化石很少,上部属于下渐新统,与含孢粉的Sandpit “Friedlich”可以对比。Lautersheim 1钻孔最上部属于晚渐新世（早Chattian),与“过滤层”顶部及“淡水层”底部可以对比,其所含的孢粉和Marxheim组合可以比较,相当于SPP 20F／G带。

AGE DETERMINATIONS OF PALYNOLOGICAL ASSEMBLAGES FROM LOWER TERTIARY OF THE EISENBERG BASIN (NORTHERN PALATINAT, GERMANY)

The Eisenberg Basin is situated in the southwestern part of the Mainz Basin and is part of the western shoulder of the Rhinegraben. The Tertiary sediments there are not comparable to the typic sequences of the Mainz Basin and because of the lack of fossils, the age of the layers in the Eisenberg Basin has been under discussion for long time. The palynostratigraphic investigation of samples from drilling core "Lautersheim 1" and from an outcrop northwest of Lautersheim (sandpit "Friedrich") indicates, according to palynological associations, three different time-spans. The lowest part of drill Lautersheim 1 belongs to the Middle Eocene (SPP-zone 15 or 16 after the zonation of Krutzsch 1966, 1970, 1992, which was established in the eastern part of Germany). Some layers of the middle section of the drill (Ebertsheim Formation below the Eisenberg Marine Sand = Eisenberger Meeressand) can be placed in the Lower Oligocene (Latdorfian stage; SPP-zone 19). This part is subdivided in two divisions, the lower part with numerous Eocene microfloristic elements and the upper part with only a few of these elements. This upper part of the Lower Oligocene correlates with the pollen-bearing horizon of the sandpit "Friedrich". The upper section of drill Lautersheim 1 (uppermost part of the Intermedium Layers = Zwischenschichten and basal part of the Freshwater Beds = SuBwasserschichten) yields pollen-spectra comparable with the "Marxheim pollen assemblage" (Marxheimer Pollenbild) or SPP-zone 20 F/G and therefore belongs to the lower Upper Oligocene (early Chattian stage).