Oceanographic and eustatic control of carbonate platform evolution and sequence stratigraphy on the Cretaceous (Valanginian–Campanian) passive margin, northern Gulf of Mexico

Abstract

An integrated sequence stratigraphic study based on outcrop, core and wireline log data documents the combined impact of Cretaceous eustacy and oceanic anoxic events on carbonate shelf morphology and facies distributions in the northern Gulf of Mexico. The diverse facies and abundant data of the Comanche platform serve as a nearly complete global reference section and provide a sensitive record of external processes affecting Cretaceous platform development. Regional cross-sections across the shoreline to shelf-margin profile provide a detailed record of mixed carbonate-siliciclastic strata for the Hauterivian to lower Campanian stages (ca 136 to 80 Ma). The study window on the slowly subsiding passive margin allows the stratigraphic response to external forcing mechanisms to be isolated from regional structural processes. Three second-order supersequences comprised of eight composite sequences are recognized in the Valanginian-Barremian, the Aptian-Albian and the Cenomanian-Campanian. The Valanginian-Barremian supersequence transitioned from a siliciclastic ramp to carbonate rimmed shelf and is a product of glacial ice accumulation and melting, as well as variable rates of mid-ocean ridge volcanism. The Aptian-Albian supersequence chronicles the drowning and recovery of the platform surrounding oceanic anoxic events 1a and 1b. The Cenomanian-Campanian supersequence similarly documents shelf drowning following oceanic anoxic event 1d, after which the platform evolved to a deep-subtidal system consisting of anoxic/dysoxic shale and chalk in the time surrounding oceanic anoxic event 2. Each period of oceanic anoxia is associated with composite sequence maximum flooding, termination of carbonate shelf sedimentation and deposition of condensed shale units in distally steepened ramp profiles. Composite sequences unaffected by oceanic anoxic events consist of aggradational to progradational shelves with an abundance of grain-dominated facies and shallow-subtidal to intertidal environments. Because they are products of eustacy and global oceanographic processes, the three supersequences and most composite sequences defined in the south Texas passive margin are recognizable in other carbonate platforms and published eustatic sea-level curves. Maraca Lisure A g u a rd ie n te Apon Rio Negro M o rr o n e d i P a c e n tr o Va lle de ll' In fe rn o T r e G r o t t e Cima Dell Murelle

Type and evolution of carbonate platforms in Jixian Period Mesoproterozoic: southwestern margin of Ordos Basin

“…The impacts of tectonism on carbonate platform Sea-level fluctuations can influence the type of carbonate platform and characteristics of gravity flow deposits (Read 1985;Reijmer et al 2012;Phelps et al 2014). Many studies have been focused on the sea-level changes of the Jixian Period of Mesoproterozoic at the eastern North China plate, but few studies try to address the problem from the southern margin of the North China plate.…”

Response and recovery of the Comanche carbonate platform surrounding multiple Cretaceous oceanic anoxic events, northern Gulf of Mexico

“…Following a Valanginian unconformity (Ewing, 2010), two mixed carbonate-siliciclastic rimmed-shelf systems, which are separated by Aptian ramp clinoforms, developed during the Hauterivian-Barremian and Albian stages (Rose, 1972;Loucks, 1976;Bebout, 1977;Scott, 1993;Phelps et al, 2014). Subtidal, mud-dominated carbonates and shales overlie the drowned Albian shelf and form the Cenomanian through lower Campanian interval (Scott et al, 1978;Dravis, 1980;Dawson, 1997;Lock and Peschier, 2006;Lock et al, 2007).…”

“…Terminal locations of the Sligo (HauterivianBarremian) and Stuart City (Albian) shelf margins formed a prominent shelf-slope break observable on regional seismic lines (Winker and Buffler, 1988;Tyrrell and Scott, 1989), and likely had shelf to basin relief on the order of hundreds of meters. Phelps et al (2014) presented a regional sequence-stratigraphic framework for the Comanche Platform by constructing a series of regional cross-sections from subsurface core descriptions, outcrop measured sections, and wireline log data. Published biostratigraphic data from the San Marcos Arch (Young, 1986), East Texas Basin (Jiang, 1989;Scott and Kerans, 2002) and shelf margins (Coogan, 1977;Waite et al, 2007) were combined with new nannofossil data to constrain regional correlations and ages of stratigraphic units.…”

“…Prior establishment of a detailed sequence-stratigraphic framework (Phelps et al, 2014) allows regional sedimentologic analysis of each OAE and its effect on the shallow-marine carbonate platform. Integration of isotopic data with lithofacies cross-sections extending from the paleo-shoreline to shelf-margin enables twodimensional analysis of the demise and recovery of the carbonate system surrounding each anoxic event.…”

Albian rudist biostratigraphy (Bivalvia), Comanche shelf to shelf margin, Texas

“…1.A & 3), is 79 m thick and is divided into lower and upper parts by an intraformational unconformity (Fig. 11) (WAITE et al, 2007;PHELPS et al, 2014). The lower part of the Stuart City below 4500 m (14,763 ft) is mainly comprised of peloid-rudist grainstone that grades up into rudist bioclastic packstone and wackestone.…”