A new DHRTC publication is out in Basin Research as Early View. It marks the conclusion of a multi-disciplinary effort of both academic researchers as well as industry professionals to tackle seismic-scale features in the chalk. Previously the seismic-scale features in the chalk were labeled ‘Funny Looking Things’, but now have gotten a geological explanation.
The study documents one of the first examples of seismic-scale diagenetic geobodies within carbonate rocks (Chalk Group), with some stunning 3D seismic geomorphological images of these features. By integrating these ‘paleo-seafloors’ with petrographical and geochemical analysis we were able to conclude that the geobodies are of an open-system diagenetic origin caused by ascending basin fluids guided by faults and stratigraphic heterogeneities.
The pathways of the fluids are now highlighted by the occurrence of the diagenetic geobodies, which cause stratigraphy cross-cutting reflectors within the Chalk Group. These features were previously labeled ‘Funny Looking Things’, but now have gotten a geological explanation due to a multi-disciplinary effort of both academic researchers as well as industry professionals. This case study provides interesting insights in (paleo-) fluid movement through carbonates causing seismic-scale diagenesis, which has been observed in outcrop in Spain and Iran by others (Martín-Martín et al., 2015; Sharp et al., 2010). The recognition of seismic-scale diagenetic geobodies can help to re-evaluate some denser parts of the chalk in producing fields, which now can have another geological explanation.
Make sure to check the images of the manuscript for some amazing paleo-seascapes shown with a seismic geomorphological approach! Happy reading!
Behind the publication
Read the whole publication for Early View.
By F.W.H. Smit1*, F.S.P. van Buchem2**, J.H. Holst1, M. Lüthje1, K. Anderskouv3, N. Thibault3, G.J.A. Buijs2, M. Welch1, L. Stemmerik4
1. Technical University of Denmark, Danish Hydrocarbon Research and Technology Centre, Elektrovej Building 375, 2800 Kongens Lyngby
2 Maersk Oil and Gas, Esplanaden 50, 1263 København K.
3 University of Copenhagen, Department of Geoscience and Natural Resource Management, Øster Voldgade 10, 1350 København K
4 University of Copenhagen, Natural History Museum of Denmark, Øster Voldgade 5-7, 1350 Copenhagen K
* Corresponding author: fsmit@dtu.dk
** Now at Halliburton-Landmark, 97 Jubilee Avenue, Milton Park, Abingdon, OX14 4RW, UK.
References:
Martín-Martín, J. D., Travé, A., Gomez-Rivas, E., Salas, R., Sizun, J. P., Vergés, J., ... & Alfonso, P. (2015). Fault-controlled and stratabound dolostones in the Late Aptian–earliest Albian Benassal Formation (Maestrat Basin, E Spain): petrology and geochemistry constrains. Marine and Petroleum Geology, 65, 83-102.
Sharp, I., Gillespie, P., Morsalnezhad, D., Taberner, C., Karpuz, R., Vergés, J., ... & Hunt, D. (2010). Stratigraphic architecture and fracture-controlled dolomitization of the Cretaceous Khami and Bangestan groups: an outcrop case study, Zagros Mountains, Iran. Geological Society, London, Special Publications,329(1), 343-396.