Application of the Graphic Correlation method to Pliocene marine sequences

摘要: Abstract Biostratigraphy — the use of paleontological evidence to establish relative chronologies, forms cornerstone many sedimentary geological investigations. Several different approaches biochronology are available. Traditional interval zones, defined on lowest and/or highest occurrences selected taxa, used place bodies rock in a chronological framework. Fossil datum levels, which more numerous than often as chronohorizons for correlation purposs. The Graphic Correlation method, like zonations, synthesizes information from number taxa but does not assume synchrony any one taxon. A magnetobiostratigraphic model deep-sea Pliocene sequences has been constructed by graphic Deep Sea Drilling project cores North Atlantic (606), Caribbean (502), South (516), Tasman (590), Equatorial Pacific (573) and (577). All hydraulic piston contain abundant planktonic foraminifers, calcareous nannofossils record magnetic reversals expected Pliocene. is based internally consistent paleontologic data gathered author. This study demonstrates advantages over conventional biostratigraphic procedures. Accurate inter-regional correlations can be made between core sites without resorting multiple microfossil zonations invoking fossil events. Important results this are: (1) foraminifer nannofossil events diachronous 0.20 m.y., (2) Globorotalia truncatulinoides first occurs Southwest Ocean, approximately 0.50 m.y. earlier previously reported, (3) undetected hiatus short duration (0.38 m.y.) exists just above Cochiti subchron at DSDP 577A.