Neogene palynostratigraphic zonation of the Marañon basin (Western Amazonia, Peru)

DI PASQUO, M.M.; BABY, P.; PARRA, FRANCISCO JAVIER; RODDAZ, M.; NAVARRETE, R.E.; CALDERÓN, Y.

PALYNOLOGY

AMER ASSOC STRATIGRAPHIC PALYNOLOGISTS FOUNDATION

Año: 2019 p. 1 - 35

0191-6122

The palynology (150 species of pollen grains, 43 species of spores, eight species of dinoflagellate cysts,five genera of algae, two genera of fungal spores, foraminiferal linings and copepod eggs) of theNeogene succession in the Maranon Basin, north Peru, was thoroughly investigated for the first time ~from six industrial wells (Arabela-1X, Maynas-1, Tucunare-1X, Tigrillo-30X, Nahuapa-24X, and LaFrontera-1). Six palynozones spanning the Early Miocene to the Early Pliocene were defined. The zonesin stratigraphically ascending order are as follows: the Mar-A Corsinipollenites oculusnoctis Zone(Aquitanian to early Burdigalian: 23.03?17.71 Ma), limited by the appearance of Acaciapollenites myriosporites, Retitricolporites wijmstrae and/or Corsinipollenites oculusnoctis and/or the disappearance ofCicatricosisporites dorogensis at the base; the Mar-B Malvacipolloides (Echitricolporites) maristellae Zone(Burdigalian: 17.71?16.1 Ma), from Malvacipolloides maristellae at the base to the disappearance ofRetitricolporites wijmstrae at the top; the Mar-C Mauritiidites crassibaculatus Zone (latest Burdigalian toLate Langhian: 16.1?14.2/13.9 Ma), from the appearance of Grimsdalea magnaclavata at the base tothe disappearance of Retitriporites dubiosus and/or the appearance of Crassoretitriletes vanraadshooveniand/or Psilastephanoporites tesseroporus; the Mar-D Crassoretitriletes vanraadshooveni Zone (LateSerravallian: 14.2?11.62 Ma), from the appearance of Crassoretitriletes vanraadshooveni and/orPsilastephanoporites tesseroporus to the disappearances of Mauritiidites crassibaculatus, Bombacaciditesnacimientoensis, and Cyathidites congoensis; and the Mar-E Psilastephanoporites tesseroporus Zone (EarlyTortonian to Late Messinian: 11.62?5.48 Ma) from the disappearance of Corsinipollenites oculusnoctisand/or Cyathidites congoensis to the disappearance of Psilastephanoporites tesseroporus and/or SiltariaQ1 santaisabelensis. These zones were corroborated by means of events ordination pointed out usinggraphic correlation. The Mar-F Ctenolophonidites suigeneris Zone (latest Messinian to Zanclean) isdescribed only in the Frontera-1 well from the disappearance of Psilastephanoporites tesseroporus tothe last record of Ctenolophonidites suigeneris and/or Siltaria hammenii. This study suggests thatPliocene sedimentation is also recorded in the Western Amazonia of Peru, and provides new palynological information compared with the Mio?Pliocene Solimoes, Acre, and eastern Amazonas basins