Distribution of calcareous nannofossils in the Miocene interval of DSDP Hole 94-608 in the north Atlantic (Fig. 1) ...
DSDP North Atlantic Site 608 yielded an excellent Miocene pelagic section which affords a further opportunity for elucidating the chronology of the calcareous nannofossil succession in the framework of magnetostratigraphic control. Most of the conventional (zonal) markers have been documented for th...
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Format: | Dataset |
Language: | English |
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PANGAEA
1992
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Online Access: | https://dx.doi.org/10.1594/pangaea.687629 https://doi.pangaea.de/10.1594/PANGAEA.687629 |
Summary: | DSDP North Atlantic Site 608 yielded an excellent Miocene pelagic section which affords a further opportunity for elucidating the chronology of the calcareous nannofossil succession in the framework of magnetostratigraphic control. Most of the conventional (zonal) markers have been documented for this site and some of the earlier results are confirmed and refined. In addition several unconventional and less known markers have been added. The first two are the highest (last) occurrence of Sphenolithus delphix and Sphenolithus capricornutus at 23.6 Ma, which is immediately above the Oligocene-Miocene boundary as identified by the last occurrence of Reticulofenestra bisecta at 23.7 Ma. The next unconventional datum is the highest (last) occurrence of Ilselithina fusa at 22.8 Ma, which is also the highest (last) occurrence of Helicosphaera recta. Calcidiscus tropicus' lowest (first) occurrence is at 19.5 Ma, which is also the lowest occurrence of Sphenolithus belemnos, and Calcidiscus leptoporus' lowest (first) ... : V = very rare (<1 specimen per 50 fields (<0.04 %), R = rare (1 specimen per 11-50 fields, ~0.04-0.18 %), F = few (1 specimen per 2-10 fields (~0.18-0.9 %), C = common (1-5 specimens per 1 field (~1.8-9 %), A = abundant (6-25 specimens per 1 field (~9-45 %), W = very abundant (>25 specimens per field (>45 %) ... |
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