Conodontes ludfordianos de la Formación Los Espejos, Precordillera Central de San Juan.

ALDO L. BANCHIG; RAÚL CARDÓ; GUILLERMO L. ALBANESI; LUIS P. FERNÁNDEZ; JUAN L. ALONSO

Tucumán

Congreso; XX Congreso Geológico Argentino; 2017

Asociación Geológica Argentina

The present contribution analyzes the conodont biostratigraphy for the uppermost strata of the Los Espejos Formation, which are exposed at the section of Poblete norte creek, in the Central Precordillera of San Juan Province. The stratigraphic interval of the study unit is made up of greenish shales interbedding sandstone beds with calcareous coquinoid layers at the base, which were sampled for conodonts. These strata are characterized by synsedimentary deformation that represents slumping processes. The bearer beds yielded hundreds of conodont elements referred to the ?Ozarkodina? parasnajdri Zone of the upper Ludfordian Stage of the Ludlow Series from a classical European scheme and North American equivalent. The virtual absence of coniform species, which are frequent in correlative strata of the Precordillera, suggests a relatively shallow open platform marine paleoenvironment for the study succession. The conodont elements are well preserved, showing a CAI 2 that indicates up to 140ºC overburden paleotemperatures for the bearer strata.