About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract

AAPG Bulletin, V. 88, No. 8 (August 2004), P. 1069-1082.

Copyright copy2004. The American Association of Petroleum Geologists. All rights reserved.

Ground-penetrating radar imaging of carbonate mound structures and implications for interpretation of marine seismic data

Lars Nielsen,1 Lars Ole Boldreel,2 Finn Surlyk3

1Geological Institute, University of Copenhagen, Oslashster Voldgade 10, DK-1350 Copenhagen K, Denmark; [email protected]
2Geological Institute, University of Copenhagen, Oslashster Voldgade 10, DK-1350 Copenhagen K, Denmark; [email protected]
3Geological Institute, University of Copenhagen, Oslashster Voldgade 10, DK-1350 Copenhagen K, Denmark; [email protected]

AUTHORS

Lars Nielsen received a Ph.D. in geology from Aarhus University, Denmark (1998). Since then, he has worked as an assistant professor at the Geological Institute, University of Copenhagen. His work includes ground-penetrating radar and seismic studies of near-surface geological structures, wavefield modeling, joint inversion of seismic and gravity data, and deep seismic investigation of the crust and upper mantle.

Lars Ole Boldreel received a Ph.D. in applied geophysics from Lulearing Technical University, Sweden (1988), followed by 10 years with the Geological Survey of Denmark and Greenland. Since 1998, he has been an associate professor at the Geological Institute, University of Copenhagen. His work includes interpretation of seismic reflection data and wire-line logs mainly offshore Faroe Islands, northeast Atlantic.

Finn Surlyk received his Ph.D. (1971) and his Dr. Scient. (1978) from the University of Copenhagen. He has been head of the Petroleum Geology Department of the Geological Survey of Greenland and is currently professor of geology at the University of Copenhagen. His interests include sequence stratigraphy, basin analysis, the great period boundaries, Cretaceous carbonates, and Jurassic clastics of the North Atlantic region.

ACKNOWLEDGMENTS

This study is supported by the Danish Natural Science Research Council. The full-wavefield calculations were initiated on the supercomputing facilities of the Danish Center for Scientific Computing. The finite-difference modeling results were computed using the software of Tesseral Technologies. The Geological Survey of Denmark and Greenland kindly provided the marine seismic data from the sea of Kattegat. Discussions with Hans Thybo, Mads Huuse, Holger Lykke-Andersen, and Erik Thomsen about high-resolution seismic data and interpretation of carbonate mounds in the Danish–Swedish area are highly appreciated. John McBrice, Carlos Pirmez, Robert Milici, an anonymous reviewer, and AAPG Editor John Lorenz commented on an earlier version of this manuscript and gave constructive comments that helped improve the paper.

ABSTRACT

Images of carbonate mound structures in Denmark and Sweden are obtained from ground-penetrating radar (GPR) reflections and outcrop analysis. The GPR data are collected in limestone quarries and provide a depth penetration of about 10 m (33 ft) and a vertical resolution of about 0.5 m (1.6 ft). The mounds are part of the northwest European Upper Cretaceous–Danian (lower Paleocene) Chalk Group, and they are similar to each other in terms of architecture, spatial distribution, and size, with widths and lengths of 30–60 m (100–200 ft) and heights of 5–10 m (16–33 ft).

Seismic reflection images from the sea of Kattegat between Sweden and Denmark and the North Sea show large (sim500–1000-m [sim1640–3280-ft]-wide and sim50–100-m [sim160–330-ft]-high) moundlike carbonate structures. Interpretations of such large mounds conflict with the GPR and outcrop observations. We address these conflicting observations. We construct realistic reference models of carbonate mound complex geometries based on the results of the GPR measurements and outcrop analysis and calculate synthetic seismic sections for the models. The modeling results show that the size of individual mounds is below the seismic resolution of 10–25 m (33–82 ft), and that interference effects caused by stacks of mounds may explain the observed large moundlike structures.

Our findings are important for the interpretation of seismic images of carbonate mound structures. Carbonate mound buildups may form traps, and correct seismic interpretation of mound complex geometry may be essential for evaluation of the nature and reservoir Previous HitpotentialTop of such structures.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].