Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Crampton, J. S. Articles by Roncaglia, L. Search for Related Content GeoRef GeoRef Citation

Detection of Late Cretaceous eustatic signatures using quantitative biostratigraphy

James S. Crampton^,1, Poul Schiøler² and Lucia Roncaglia³

¹ GNS Science, P.O. Box 30-368, Lower Hutt, New Zealand
² The Geological Survey of Denmark and Greenland, Ø. Voldgade 10, DK-1350, Copenhagen K., Denmark
³ Danish Oil and Natural Gas A/S, Agern Alle 24-26, DK-2970 Hørsholm, Denmark

This study tested the potential for high-resolution quantitative biostratigraphic methods to distinguish tectonic from supposedly eustatic sequences. The study employed automated multidimensional graphic correlation using constrained optimization (program CONOP). Our analysis was based on 15 onshore sections in eastern New Zealand spanning the Coniacian to Maastrichtian stages (Upper Cretaceous), and 398 well-constrained lowest- or highest-occurrence records derived from 245 dinoflagellate species. The age of the resulting composite section was calibrated using six dated bioevents; two of these events were tied to geochemical or paleomagnetic datums. Following calibration, the composite section had an average relative temporal resolution of less than 130 k.y. through the study interval, although the succession of events was not dated to this level of precision in an absolute sense. Although the CONOP composite will not resolve unconformities or condensed intervals that occur across all studied sections, such "global" unconformities can be identified using clusters of events that are placed at a single composite level. Fifteen major event clusters were identified, 10 of which coincided closely with sequence boundaries identified in the Northern Hemisphere; the probability of this coincidence arising by chance alone is 8%. Although these results must be regarded as provisional, they suggest that high-resolution quantitative stratigraphy can provide a potent tool for the identification and correlation of stratigraphic sequences. Furthermore, our findings add significant support for recent studies that have argued for the presence of Late Cretaceous eustasy.

Key Words: biostratigraphy • correlation • eustasy • Late Cretaceous • New Zealand • quantitative analysis • sequence stratigraphy • unconformities

This article has been cited by other articles:

				T. O. Somme, W. Helland-Hansen, and D. Granjeon Impact of eustatic amplitude variations on shelf morphology, sediment dispersal, and sequence stratigraphic interpretation: Icehouse versus greenhouse systems Geology, July 1, 2009; 37(7): 587 - 590. [Abstract] [Full Text] [PDF]

				C. A. LANDIS, H. J. CAMPBELL, J. G. BEGG, D. C. MILDENHALL, A. M. PATERSON, and S. A. TREWICK The Waipounamu Erosion Surface: questioning the antiquity of the New Zealand land surface and terrestrial fauna and flora Geological Magazine, March 1, 2008; 145(2): 173 - 197. [Abstract] [Full Text] [PDF]