000			03717nmc a2200265 4500
005			20260520010450.0
008			260224s xxu
082			_a068.82 553.28 C62 15730
210			_aSimposio sobre la Exploración Offshore en el Sector Sur del Margen Atántico Sudamericano
245	0	0	_aEVOLUCIÓN DEL MARGEN ATLÁNTICO ARGENTINO DURANTE EL CRETÁCICO TARDÍO
270			_a16/11/2023 ; 16/11/2023
300			_a24 p. ; 199-222
520			_aThe Argentine Atlantic margin preserves a passive margin geologic record spanning from Jurassic to Cenozoic times. According to seismic, gravmag and well data, the rifting event that preceded the breakup of the South Atlantic is recorded underneath the shelf. Rifting was followed by a sag stage which finally leads to the development of seaward dipping reflectors (SDRs), located along the transition between continental and oceanic crust. SDR emplacement occurred at surface, fed by faults that propagated along segments bound by fracture zones. Those fracture zones accommodated rotational strain between plates during breakup. By Barremian-Aptian times (120-110 Ma) first marine ingression covered those fractures zones and expanded onto the SDRs and the continental crust. Ongoing transgression promoted development of coastlines and, where clastic supply was reduced, backstepping carbonate factories. During Albian-Cenomanian times, decreasing accommodation rates and increasing sediment supply, a narrow (30-40 km) shelf developed as a consequence of prograding clinoforms on an initial ramp setting, internally marked by a higher frequency alternance of regressions and flooding events. Those clinoforms prograded into a shallow sea, as their height does not exceed 300 m and were dominated by slope related gravity flows, with the development of toe of slope fans and comparatively small gully systems on the slope alternating with grain flows. The boundary between Cenomanian and Turonian times (93 Ma) is marked by a significant deepening of the basin, related to the final split between the Malvinas Plateau and SW Africa. The unconformity record and the following flooding mark the change from a stratigraphic shelfbreak built from a ramp setting to a structurally enhanced shelfbreak. This event marks the onset of a deepwater environment, with slope canyons, levees and basin floor fans, reworked by thermohaline currents. Deep marine conditions coupled to a narrow shelf favoring efficient sediment transfer downslope prevailed until Campanian-Maastrichtian times (ca. 66 Ma), when a regional unconformity developed cutting deep into the shelf and resulting in collapse of the slope. Accumulation of mass wasting along the toe of the slope created a complex topography that ponded deposits of lower density turbidite flows that followed. In addition, erosional scars left behind by mass transport deposits downslope, confined laterally turbidite flows. The transgression that followed connected foreland basins such as the Neuquén Basin, with the South Atlantic as well as the Golfo San Jorge Basin, although highlands separating the basins under the shelf were only flooded by Middle Miocene times
773			_g
942			_cCONGTP
100	1		_aKress, Pedro _95697
100	1		_aSilio, Ofelia _961095
100	1		_aCatuneanu, Octavian _935506
100	1		_aRojas Vera, Emilio _958786
100	1		_aSpäth, Federico _9997
100	1		_aBolatti, Néstor _930198
111	2		_aCongreso de Exploración y Desarrollo de Hidrocarburos (11er : 2022 nov. 8 - 11 : Mendoza) _961064
999			_c196221 _d196221
856			_uhttps://biblioteca.iapg.org.ar/ArchivosAdjuntos/Conexplor2022/Simp.Explor.Offshore/offshore14.pdf