Givetian-Frasnian microfloras from the Tarija Basin, Northern Argentina, and their relationship with the global eustasy and palaeoclimate

NOETINGER, S., DI PASQUO, M.

Jujuy

Congreso; XVII Congreso Geologico Argentino,; 2008

Asociación Geológica Argentina

The microfloras from Bolivia and Argentina have recently provided important evidence to extend the knowledge on the biodiversity and the succession of floristic events during the Middle Devonian (see di Pasquo et al., 2007). Two recently investigated boreholes, San Antonio X-1 (SA) and Tonono X-1 (To) (Figs. 1, 2) contribute with new information about palynofloral changes especially during the Givetian and early Frasnian in northwestern Argentina (Noetinger and di Pasquo, 2007, 2008). The reasons of these changes are briefly discussed in this contribution. A gradual change on the composition of the palynofacies from the Givetian to the early Frasnian palynofloras showing an increase of the content of amorphous organic matter and pyritization of palynomorphs and the dominance of marine microplankton over land-plant miospores, is recorded (Fig. 2).