A mid-Cretaceous palynoflora with Tucanopollis crisopolensis from D-129 Formation, San Jorge Gulf Basin, Argentina

Abstract

-New data from the palynomorph assemblage with angiosperm pollen grains found in lacustrine sediments belonging to the terminal part of the D-129 Formation are herein presented. The fossiliferous section is included in the uppermost part of a thick lacustrine stratigraphic unit, which is widely distributed in the subsurface of the productive San Jorge Gulf Basin. The presence of the paleoequatorial marker Tucanopollis crisopolensis (Regali) in the studied sediments is emphasized and biostratigraphic as well as biogeographic aspects are discussed. Based on the information provided by the fossil record, a late Barremian?/early Aptian age is suggested for the end of the great-lake episode in the present district.

First Report of a Maastrichtian Palynoflora from the Golfo San Jorge Basin, Central Patagonia, Argentina

“…The Pozo D-129 Formation, which represents the main hydrocarbon source rock in the basin, includes late Barremian?-early Aptian palynoflora recovered from sediments exposed in the Sierra Silva. Such palynoflora, with primitive angiosperm pollen grains, includes the significant presence of the paleotropical marker Tucanopollis crisopolensis (Regali et al, 1974) Regali, 1989(Vallati, 2013a. A middle Cretaceous microflora was previously reported from the Caleta Olivia Member of the Cañadón Seco Formation (subsurface of the Santa Cruz Province in the southern flank of the basin) by Archangelsky et al (1994).…”

“…Previous Cretaceous palynological studies in the productive Golfo San Jorge Basin involve both subsurface and exposed units (Van Nieuwenhuise and Ormiston, 1988;Archangelsky et al, 1984Archangelsky et al, , 1994Vallati, 2013a). Based on the stratigraphic distribution of selected species, Archangelsky et al (1984) defined several palynological assemblages in the Lower Cretaceous (Berriasian-Aptian) of the basin.…”

First megafloristic record for the Chubut Group at Somuncurá-Cañadón Asfalto Basin: An angiosperm dominated flora from the Upper Cretaceous Puesto Manuel Arce Formation, Patagonia Argentina

“…Romero and Arguijo, 1981;Romero and Archangelsky, 1986;Papú, 1989;Romero, 1993;Passalia et al, 2001;Llorens, 2003;Cúneo and Gandolfo, 2005;Gandolfo and Cúneo, 2005;Quattrocchio et al, 2005;Barreda and Archangelsky, 2006;Iglesias et al, 2007;Passalia, 2007;Narv aez and Sabino, 2008;Povilauskas et al, 2008;Puebla, 2009;Vallati, 2010Vallati, , 2013Perez Loinaze et al, 2012;Archangelsky and Archangelsky, 2013;Povilauskas, 2013). Most of these Cretaceous records are concentrated in two time intervals: the Aptian (late Barremian?)…”

“…Palynological studies of the Chubut Group include assemblages from outcrops of Pozo D-129 Formation (Aptian) and subsurface deposits of Cañad on Seco (¼Bajo Barreal Formation, Cenomanian) (Archangelsky et al, 1994;Vallati, 2013). Moreover, in the Somuncur a-Cañad on Asfalto Basin, the palynological record of the Chubut Group is restricted to subsurface assemblages of the lower Albian Los Adobes Formation (Marveggio and Llorens, 2013) and an unpublished report from the Albian-mid Cenomanian Cerro Barcino Formation (Pothe de Baldis, 1976in Page, 1987.…”

Cretaceous angiosperm pollen from the Kachaike Formation, south-western Santa Cruz Province, Argentina

“…The earliest known angiosperms appeared in a landscape dominated by Cretaceous gymnosperms and ferns. Primitive angiosperms have been the subject of intensive study in the northern hemisphere, but records of primitive angiosperms in southern South America remain scarce despite recent efforts to improve it (Vallati 2001(Vallati , 2013; Barreda and Archangelsky 2006;Archangelsky et al 2008;Medina et al 2008;Archangelsky and Archangelsky 2013, among others).…”