Edad y ambiente de la Serie del Yeso, Valle del Cura, provincia de San Juan.

BARREDA, V. D.

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 1998 vol. 35 p. 321 - 335

0002-7014

ABSTRACT.AGE ANO PALAEOENVIRONMENT OF THE "SERIE DEL YESO", VALLE DEL CURA, SAN JUAN PROVINCE:PALYNOLOGICAL EVIDENCE. A diverse and well preserved palynological assemblage is reported for the first time from the Uppersection of the "Serie del Yeso", San Juan province, Argentina. The assemblage is dominated by herbaceous and shrubby formsof the families Cyperaceae, Poaceae, Malvaceae, Sympocaceae, Asteraceae, Anacardiaceae and Ephedraceae which, on sedimentologicaland palynological grounds, may have developed in the surroundings of a lacustrine environment. Tree components and femsare very sparse. Fresh water algae, mainly Botryococcus, are abundant. A few dinoflagellate cysts and acritarchs are present in thisassemblage which may suggest brackish conditions in the lake. The great development of gypsum seams in the Upper Section of the"Serie del Yeso" is in accord with this assumption. The spore-pollen assemblage suggests warm to warm temperate and dry climateconditions. This assemblage also suggests a Miocene age for this unit, probably Middle Miocene. A new combination, Mutisiapollisviteauensis (Barreda) Barreda combo nov., is here proposed. Cyperaceaepollenites neogenicus Krutzsc 1970 and Tetracolporitesspectabilis Pocknall and Mildenhall 1984 are reported for the first time from Argentina.