Assessing the origin of pisoids within a travertine system in the border of Puna Plateau, Argentina

Sedimentology ◽  
2021 ◽  
Author(s):  
R. Agustin Mors ◽  
Fernando J. Gomez ◽  
Ricardo A. Astini ◽  
Aaron J. Celestian ◽  
Frank A. Corsetti
Keyword(s):  
Puna Plateau

The late Miocene eolian record at the eastern margin of the Puna Plateau, NW Argentina: Evidence of upper-tropospheric paleocirculation

2022 ◽  
Vol 92 (1) ◽  
pp. 32-49
Author(s):  
Jonathan Ledesma ◽  
Cecilia E. Del Papa ◽  
Patricio Payrola
Keyword(s):  
Atmospheric Circulation ◽  
Late Miocene ◽  
Amazon Basin ◽  
Coarse Grained ◽  
Small Scale ◽  
Provenance Analysis ◽  
Humid Climate ◽  
Upper Troposphere ◽  
Facies Associations ◽  
Puna Plateau

Abstract The Puna–Altiplano Plateau of the Central Andes is the second-highest plateau in the world (after Tibet), with a mean elevation of 4000 m.a.s.l. and an arid to hyperarid climate. Uplift of the Puna–Altiplano Plateau has affected lower-level atmospheric circulation, acting as a barrier to humid easterly winds from the Amazon basin and favoring an across-strike precipitation gradient resulting in a humid climate towards the east of the plateau and an arid to hyperarid climate in the orogen's interior. In the modern climate, the Bolivian High anticyclone regulates upper troposphere circulation, but little is known about the high-altitude tropospheric circulation of the past. This work focuses on the eolian record of the San Antonio de los Cobres basin along the eastern border of the Puna Plateau, NW Argentina, with the aim of analyzing its origin and thus elucidating the late Miocene winds. The eolian deposits are constrained by 7.8 Ma (K/Ar and U/Pb) and 6.4 Ma (U/Pb) ignimbrites at the nearly basal and upper contacts, respectively. Based on stratigraphic, sedimentological, and provenance analysis of the eolian units, we have identified three main facies associations (FAs): FA1) cross-stratified sandstones with large- to small-scale tabular, planar cross-bedding and with trough cross-stratification; FA2) sandstones with planar to low-angle stratification associated with thinly laminated ripple sandstone strata; FA3) medium- to coarse-grained massive sandstones associated with pebbly to bouldery, matrix-supported conglomerates and clast-supported conglomerates. The lateral and vertical facies assemblages indicate a dune field confined to topographic depressions dominated by transverse dunes with straight and sinuous crestlines that laterally grade into sandsheets associated with ephemeral streams. Paleoflows, lithotypes, and grain-size determinations indicate a persistent north-northwest provenance and wind velocities of 24–38 km/h (with maximum velocities of 55–75 km/h). The results of our analysis coupled with data from previous studies indicates that, for at least the last ca. 8 Myr, the winds have been blowing constantly from the north-northwest with an intensity similar to the present. This implies that the paleo-atmospheric circulation had a similar pattern to the present-day one. Therefore, we conclude that the upper-troposphere circulation in the Puna Plateau of NW Argentina was already regulated by the Bolivian High anticyclone during the Miocene, generating constant north-northwesterly winds.

scholarly journals Lithium and Brine Geochemistry in the Salars of the Southern Puna, Andean Plateau of Argentina

2020 ◽  
Vol 115 (5) ◽  
pp. 1079-1096
Author(s):  
Romina Lucrecia López Steinmetz ◽  
Stefano Salvi ◽  
Carisa Sarchi ◽  
Carla Santamans ◽  
Lorena Cecilia López Steinmetz
Keyword(s):  
South America ◽  
Regional Scale ◽  
Small Region ◽  
Easy Access ◽  
Northern Chile ◽  
Geographical Pattern ◽  
Hydrochemical Data ◽  
Puna Plateau ◽  
Brine Chemistry ◽  
Salt Pan

Abstract The Andean plateau is a small region of South America extending between northwest Argentina, southwest Bolivia, and northern Chile. It concentrates the largest global resources of lithium brines in its numerous salars. Of these, the giant salars in Bolivia and Chile have been relatively well studied; however, only little is known about the smaller but numerous salars in the Argentine Puna region. In this article, we present the results of the first regional-scale reconnaissance exploration of the 12 major salars situated in the southern part of the Puna plateau (24°S–26°30’S). Hydrochemical data indicate that the shallowest brines are characterized by highly variable Li concentrations, with mean Li grades ranging between 57 and 570 mg L−1, and mean Li/Mg ratios from 0.01 to 1.24. A survey of the brine chemistry of the salars across the Puna plateau, including its northern part, has revealed the absence of a geographical pattern in Li+ grade distribution. However, a comparison among mean Li+ grades, Li+/Mg2+ ratios, and the sizes of all salars allows an estimation of their Li mining potential. Specifically, the salt pan of Arizaro represents the highest potential, mainly due to its size; Antofalla-Botijuelas has a large surface and promising Li/Mg ratios for Li recovery via brine evaporation, though its elongated shape is a constraint; and Pastos Grandes, Pozuelos, and Rincón have encouraging Li grades, interesting salar sizes, and relatively easy access. Olaroz, Cauchari, and Hombre Muerto contain the highest Li+ grades in brines of the Argentine Puna and embody the most interesting perspectives of the Argentine plateau in a regional context. Salar sizes could be related to maximum Li+ grade of brines. Larger salars would then be expected to contain brines with higher Li+ grades than smaller ones, which could be considered as a useful criterion for surveys of brine-type deposits.

Digital Geological Map of the Southern and Central Puna Plateau, NW Argentina

2006 ◽  
pp. 563-564 ◽  
Author(s):  
Wolfgang B. W. Schnurr ◽  
Andreas Risse ◽  
Robert B. Trumbull ◽  
Kerstin Munier
Keyword(s):  
Puna Plateau ◽  
Geological Map

Late Cenozoic topographic evolution of the Eastern Cordillera and Puna Plateau margin in the southern Central Andes (NW Argentina)

2020 ◽  
Vol 535 ◽  
pp. 116112 ◽  
Author(s):  
Heiko Pingel ◽  
Manfred R. Strecker ◽  
Andreas Mulch ◽  
Ricardo N. Alonso ◽  
John Cottle ◽  
...  
Keyword(s):  
Central Andes ◽  
Late Cenozoic ◽  
Eastern Cordillera ◽  
Puna Plateau ◽  
Southern Central ◽  
Topographic Evolution

Thermal and geodynamic contributions to the elevation of the Altiplano–Puna plateau

2014 ◽  
Vol 237 ◽  
pp. 51-64 ◽  
Author(s):  
Claudia Prezzi ◽  
María Paula Iglesia Llanos ◽  
Hans-Jürgen Götze ◽  
Sabine Schmidt
Keyword(s):  
Puna Plateau
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