In sequence stratigraphy, condensed sections are strata that are thin, yet span a large time interval. They are associated with the maximum flooding surfaces, represented by sedimentary intervals deposited during the maximum marine transgression.[1]
Characterization and identification
editDuring the maximum marine transgression, shoreline advances landward furthest and the marine environments generally become widespread and deep. With terrigenous sediment supply being farther away, sediments are in thin bed characterized by fine-grain particles of distal facies with low rates of sedimentation, and with relative less dilution by terrigenous influx, sediments are highly fossiliferous and contain rich organic contents. These characters allow condensed sections to be readily recognized by identifying maximum flooding surfaces on seismic profile,[2] analyzing the sedimentary intervals with maximum faunal abundance and diversity in outcrops and cores[3] , and by finding the gamma-ray peaks in well-log data.[4][5]
Application
editCondensed sections, as the best chronological markers, are primary important in stratigraphic correlation, between shallow and deep marine depositional environments. Furthermore, they play a fundamental role in identifying systems tracts to predict depositional facies changes and the associated lithological variations [6] .[7]
References
edit- ^ Catuneanu, Octavian (2011). "Sequence stratigraphy: methodology and nomenclature". Newsletters on Stratigraphy. E. Schweizerbart'sche Verlagsbuchhandlung.44(3): 190
- ^ Van Wagoner, J.C., 1988. AN OVERVIEW OF THE FUNDAMENTALS OF SEQUENCE STRATIGRAPHY AND KEY DEFINITIONS.SEPM Special Publication ISBN 0-918985-74-9
- ^ Armentrout, J M, Echols, R J, and Lee, T D. Patterns of foraminiferal abundance and diversity: Implications for sequence stratigraphic analysis. United States: N. p., 1991.
- ^ Milton, N.J., Bertram, G.T., and Vann, I.R., 1990. Early Palaeogene tectonics and sedimentation in the Central North Sea. In Hardman, R.F.P., and Brooks, J. (Eds.), Tectonic Events Responsible for Britain's Oil and Gas Reserves. Geol. Soc. Spec. Publ. London, 55:339-351.
- ^ Armentrout, J.M., Malecek, S.J., Fearn, L.B, Sheppard, C.E., Naylor, P.H., Miles, A.W., Desmarais, R.J., and Dunay, R.E., 1993. Log-motif analysis of Paleogene depositional systems tracts, Central and Northern North Sea: defined by sequence stratigraphic analysis. In Parker, J.R. (Ed.), Petroleum Geology of Northwest Europe: Proceedings of the 4th Conference. Geol. Soc. Spec. Publ. London, 45-57.
- ^ Bruce E. Bowen, Bernard L. Shaffer, D. L. Dunn, Jory A. Pacht, and John H. Beard, (1989), "Seismic identification and use of condensed sections in the Plio‐Pleistocene, Gulf of Mexico," SEG Technical Program Expanded Abstracts : 801-802.https://doi.org/10.1190/1.1889777
- ^ TOM S. LOUTIT, JAN HARDENBOL, PETER R. VAIL AND GERALD R. BAUM(1988)CONDENSED SECTIONS: THE KEY TO AGE DETERMINATION AND CORRELATION OF CONTINENTAL MARGIN SEQUENCES. In Sea-level changes – An integrated approach. SEPM Special Publications No. 42