The Canal de las Montañas Shear Zone (CMSZ), southern Patagonian Andes (51–52°S), is a low-grade mylonite belt generated from felsic ignimbritic, pelitic and basaltic protoliths of the Late Jurassic–Early Cretaceous Rocas Verdes basin. The different types of rock fabrics across the CMSZ are thought to be associated with relatively intermediate and high strain conditions, characterized by the development of a narrow western belt of S–C´-type mylonites and phyllonites interpreted as the metamorphic sole thrust of the Sarmiento Ophiolitic Complex. Highly strained rocks of the CMSZ display a reverse, continent-ward tectonic transport, with a minor dextral component of shearing. Transitional pumpellyite–actinolite and upper greenschist facies metamorphic conditions at ca. 5–6 kbar and 230–260 °C indicate that the primary shearing event occurred in a subduction zone setting. In-situ 40Ar/39Ar laserprobe chronology yielded ages of ca. 85 Ma on syntectonic phengite which are interpreted as representing cooling synchronous with mica crystallization during the main compressive deformational event. The 78–81 Ma U–Pb zircon crystallization ages of crosscutting plutonic and hypabyssal rocks and 40Ar/39Ar amphibole age of ca.79 Ma from lamprophyric dikes within the fold-thrust belt constrain an upper age limit of the ophiolite tectonic emplacement deformation.This work was supported by Initiation Fondecyt grant 11075000 to M.C., and the international collaboration grants of the GRICESCONICYT (José Munhá and M.C.) and the BMBF-CONICYT (H.-J.M. and F.H) programs. This research paper is a contribution of Anillo Project ACT-105 of CONICYT and PBCYT

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Summary Microbialite‐producing microorganisms that inhabit the Puna lakes are traditionally considered constituents of fragile microsystems, unable to resist important environmental variations. Nevertheless, this region has experienced significant climatic fluctuations during the Holocene, raising the unsolved issue on how microbialite‐forming systems have been able to resist these changes. Turquesa lake, located within Quaternary Peinado lake‐basin (Puna), faces a hydric crisis in the last decades, which modified their physicochemical conditions. However, there has been a rapid re‐establishment of the microbialite systems once the main parameters were stabilized, which allowed the establishment of three new microbialite levels in the coast and paleo‐coastline. The aim of this contribution is to report for the first time microbialite levels in Turquesa lake, providing a multiscale analysis, besides an accurate study of the physico‐chemical context of the lake. This new record provided us the opportunity to demonstrate the short‐term resilience capacity of these microbialite‐producing microorganisms to climatic changes, offering a key approach to understand analogue processes throughout Earth history.

The Paranaguá Terrane is composed of precambrian geological units distributed in a NE-SW elongated swath, about 250 km long and 30 km wide, in south-southeastern Brazil, within the States of São Paulo (Nothern Paranaguá Terrane), Paraná and Santa Catarina (Southern Paranaguá Terrane). This terrane is constituted mainly by an igneous complex, represented by the Morro Inglês, Rio do Poço and Canavieiras-Estrela suites. The country rocks of these l.s. granites are gnaissic and gnaissic-migmatitic rocks of the São Francisco do Sul Complex and metassedimentary rocks of the Rio das Cobras Sequence. Lithochemical signatures of the Morro Inglês Suite are compatible with arc magmatic-generated granitic rocks, with high-K to shoshonitic calc-alkaline character and relatively high contents of Ba, Nb, Zr, Rb, Sr, Th and K 2 O. This pattern resembles the one observed in sin-to late-collisional environments related to mature magmatic arcs, with sources modified by crustal contamination. The Canavieiras-Estrela Suite is composed of quartz-monzodiorites, leucogranites and monzogranites, with porphyritic and inequigranular rocks, with mafics represented by biotite ± anfibole. Comparativily, the Morro Inglês Suite rocks present higher values of K 2 O and smaller values of Na 2 O than the rocks of the Canavieiras-Estrela Suite. Both suites show important variations of Ba and Sr, high values of Rb and Zr, and medium-to-high values of Nb and Y. Two distinct rock units can be individualized in the Rio do Poço Suite, based on petrographical and lithogeochemical differences. The rapakivi sienogranites characteristics are compatible with metaluminous to marginally peraluminous type A granites. Such interpretation does not seem adequate for the two-mica leucogranites in this suite, which present a marginally peraluminous character, with HREE-depleted rocks, without an Eu negative anomaly. Petrographic and, mostly, structural data suggest that the Morro Inglês, Canavieiras-Estrela and Rio do Poço suites emplacement occurred during a late stage of the collisional event. U-Pb ages (zircon) of these suites are very close and does not allow a clear separation of them. A high concentration of ages between 600-580 Ma represent the main magmatic period of the Paranaguá Terrane. Although less frequent, older ages between 620-610 Ma were obtained in the three suites, suggesting the presence of a relatively early magmatism in this terrane's evolution. U-Pb ages (zircon) obtained in crystals borders, as well as in late leucogranitic veins, are distributed between 560-480 Ma. These ages must be related with important thermotectonic events of the Cambro-Ordovician Rio Doce Orogeny. The metassedimentary rocks of the Rio das Cobras Sequence occur as elongated strips, with little areal expression. In the southern portion of the Paranaguá Terrane, green schist (biotite zone) paragenesis are present (Serra da Prata -PR), while in the central and northern portions there are afibolite facies paragenesis up to granulite facies in association with kyanite-garne...