%0 Journal Article
%T Estratigraf¨ªa, mam¨ªferos f¨®siles y edad de las secuencias volcanosedimentarias eoceno-miocenas de la sierra de Huantraico-sierra Negra y cerro Villegas (provincia del Neuqu¨¦n, Argentina)
%A Garrido
%A Alberto
%A Kramarz
%A Alejandro
%A Forasiepi
%A Anal¨ªa
%A Bond
%A Mariano
%J Andean geology
%D 2012
%I Scientific Electronic Library Online
%R 10.5027/andgeoV39n3-a07
%X we present here the recent advances in understanding the stratigraphy and age of the cenozoic volcanic and sedimentary sequences exposed on the area of sierra huantraico-sierra negra and cerro villegas (pehuenches department, neuqu¨¦n province). stratigraphic analyses and recovered fossil remains allow us to recognize and differentiate six litostratigraphic units: a. the 'rodados lustrosos' (late eocene-early? oligocene), composed of coarse-grained texturally mature conglomerates (up to 18 m thick), deposited on a strong paleorelief of eroded pre-eocene sedimentary rocks (inca diastrophic phase); b. the rinc¨®n escondido formation (nom. nov.) (early oligocene-lower late oligocene), composed of sandy fluvial deposits linked to a strong pyroclastic source (31 m), occupies and fills the same paleorelief on which the 'rodados lustrosos' lies; c. the sierra negra formation (nom. nov.) (aquitanian-burdigalian, early miocene) overlies a younger paleorelief that erodes into deposits as old as early cretaceous (pehuenche diastrophic phase); this unit can be subdivided into the filo morado member (up to 250 m of olivine-alkaline basalts, pyroclastic rocks, and volcanogenic deposits) and the puesto tiller¨ªas member (nom. nov.) (up to 600 m of basalts and andesitic rocks with interbedded tuffs and tuffites); d. the pichi tril formation (late burdigalian-langhian) is composed of andesitic intrusive bodies linked to deformation that occurred by the end of the early miocene (quechua diastrophic phase); e. the desfiladero negro formation (early tortonian) forms a set of basic dikes that cross the rest of the succession - an intrusion related to earliest late miocene deformation; f. the la tiza formation (late? tortonian-early messinian, late miocene), composed of up to 85 m of coarse-grained oligomictic conglomerates with low textural maturity, originated from the erosion of volcanic bodies and basaltic flows of the sierra negra formation. this entire succession was again deformed at
%K stratigraphy
%K paleontology
%K cenozoic
%K neuqu¨¦n
%K patagonia.
%U http://www.scielo.cl/scielo.php?script=sci_abstract&pid=S0718-71062012000300007&lng=en&nrm=iso&tlng=en