Transgressive/Regressive (Second Order) Facies Cycles: The Effects of Tectono-Eustasy
Published:January 01, 1999
Thierry Jacquin, Pierre-Charles de Graciansky, 1999. "Transgressive/Regressive (Second Order) Facies Cycles: The Effects of Tectono-Eustasy", Mesozoic and Cenozoic Sequence Stratigraphy of European Basins, Pierre-Charles de Graciansky, Jan Hardenbol, Thierry Jacquin, Peter R. Vail
Download citation file:
Transgressive/regressive facies cycle analysis combines the approaches of sequence stratigraphy at outcrop/core/well-log scales and seismic stratigraphy at seismic scales (large-scale stratal pattern and termination), to determine the facies stacking pattern and the partitioning of sediments following long-term changes in shelfal accommodation. Thus, it is an interdependent approach with the main purpose being to build a hierarchy of stratigraphic cycles.
The building blocks of transgressive/regressive (T/R) facies cycles are 3rd-order depositional sequences. Four types of 3rd-order depositional sequences may develop within a 2nd-order transgressive/regressive facies cycle: infilling and forestepping during the regressive phase and aggrading and backstepping during the transgressive phase. These four types of sequences do not occur systematically together within a second-order cycle. Four end-members of T/R cycles can be defined depending on (1) the capability of sediment deposition to keep up with relative sea-level rises; (2) the rates at which accommodation space changes. The four end-members will include (1) T/R cycle with or without aggrading sequences and (2) T/R cycles with or without forestepping sequences.
About 18 T/R cycles have been found within the Western European Mesozoic stratigraphic successions. At the craton scale, some of the characteristic surfaces and events are very synchronous. This synchroneity suggests a tectono-eustatic control. Cycles which are not synchronous within a basin usually result from variations in local sea-floor subsidence/uplift. This can be seen particularly in the syn-rift and syn-compressional successions.
Both the type and occurrence of 3rd-order sequences (in respect to stratigraphy, depositional environments, reservoirs, source rocks and facies) depends of the type of 2nd-order cycle to which they belong. A full understanding of these characteristics observed in the data is essential to the analysis of the stratigraphic signature of a basin.
Figures & Tables
Mesozoic and Cenozoic Sequence Stratigraphy of European Basins
Mesozoic and Cenozoic Sequence Stratrigraphy of European Basins - This project was designed to build a documented chronostratigraphic and outcrop record of depositional sequences calibrated across European Basins. Data on standard stages, magnetostratigraphy, and geochronology integrated with high resolution biostratigraphy calibrate the stratigraphic position of depositional sequence boundaries. Higher order eustatic sequences show a significant increase in the number identified. A good portion of the European Mesozoic and Cenozoic succession is set in a sequence stratigraphic context with a better stratigraphic record of its bonding surfaces.