Deepwater Facies Architecture and Evolution of Middle and Lower Miocene Minibasins in the Onshore Salina Basin, Southeastern Mexico
Ambrose, William A.1, Renaud Bouroullec1, Khaled
Fouad1, Rebecca Jones1, Edgar H. Guevara1,
Emilio Garciacaro1, Alejandro Alberto Sosa Patron2, Jaime
Patino Ruiz2, and Juan de Guadalupe Cardenas Lopez2
1 The University of Texas at Austin, Austin, TX
2 PEMEX Exploración y Producción, Villahermosa, Mexico
Lower Neogene minibasins in the onshore part of the Salina Basin in southeastern Mexico were associated with episodic, northward salt mobilization and withdrawal. These minibasins are penetrated by few wells and are relatively unexplored. They are characterized by cyclic deposition of upper-slope turbidites and debris-flow deposits sourced from the Chiapas Fold Belt to the south.
Middle Miocene sandy slope-channel facies in the Ogarrio area are 10- to 15-m, upward-fining successions of porous, fine- to medium-grained, crossbedded and plane-bedded sandstone with subangular clay clasts and poorly sorted organic fragments at the base. These channel deposits are flanked by thin (<5-cm scale), rippled and laminated, low-porosity, very fine grained sandstones interbedded with burrowed siltstone.
The sparsely drilled lower Miocene minibasin fill is interpreted to
contain numerous intrabasin unconformities that underlie dim-amplitude, 70- to
120-m, chaotic seismic facies. These chaotic zones are interpreted to be muddy
debris-flow and slump deposits, similar in seismic character and geometry to
those of Pliocene strata in the Auger minibasin in offshore Louisiana. These
lower Miocene chaotic zones are overlain by relatively thin, bright
-amplitude,
single-cycle zones, typically 20 to 40 m thick. These
bright
-amplitude zones,
extremely continuous, are interpreted to represent potentially sandy turbidite
lobe and sheet deposits. The overall minibasin fill is relatively dim amplitude
updip to the south, whereas
bright
amplitudes are more common downdip northward,
indicating a muddy bypass slope system grading into sandier, ponded turbidite
facies into the basin.
AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005