Tectonic evolution of the northern Malargue Fold and Thrust Belt, Mendoza province, Argentina
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
Authors: Martos, Federico E.; Fennell, Lucas M.; Brisson, Sofia; Palmieri, Guillermo; Naipauer, Maximiliano; Folguera, Andres
Abstract
In this work we study the evolution of one particular segment of the Southern Central Andes, the northern sector of the Malargue Fold and Thrust Belt (34 degrees-35 degrees LS), where limited access to the western section has delayed its exploration for years. Analyses of the structure, stratigraphy and sedimentology of different sections along the fold and thrust belt added to the recognition and analysis of growth strata geometries within the foreland basin allowed us to perform an evolutionary model. Our results suggest that during the Lower Jurassic a rift-related depocenter, the Alto Atuel depocenter, developed next to the international border between Argentina and Chile, which was characterized by an important volcanic contribution from the magmatic arc. During the Late Jurassic, a new extensional episode took place at these latitudes, where synextensional deposits were found in the Alto Atuel depocenter, suggesting that this region has suffered multiple extensional processes during the Jurassic. Growth strata within the Late Cretaceous Diamante Formation suggest that the orogenic front reached an eastern location at this time. Sedimentary and petrographic analyses support the hypothesis that the Diamante Formation represents a synorogenic unit. Furthermore, petrographic and provenance analyses developed in the Late Cretaceous to Miocene deposits suggest that during the Paleogene the main source areas were the magmatic arc and the Mesozoic deposits exhumed by the Andean orogen, in accordance with detrital zircon ages published by other authors. The final development of the fold and thrust belt during Neogene time generated growth strata within the wedge top section of the foreland basin. The detection of these geometries within the Agua de la Piedra Formation suggests that the last Neogene compressional phase started between 20 and 15 Ma.
High-temperature solid particle erosion of Cr-Ni-Fe-C arc cladded coatings
WEAR
Authors: Efremenko, B., V; Shimizu, K.; Espallargas, N.; Efremenko, V. G.; Kusumoto, K.; Chabak, Yu G.; Belik, A. G.; Chigarev, V. V.; Zurnadzhy, V., I
Abstract
In the present work two arc weld cladded alloys A (C3Cr25Ni3Si3) and B (C5Cr4ONi40Si2BZr) were tested under solid particle erosion at higher temperature (500 degrees C and 800 degrees C). The alloys were cladded using flux-cored strips PL-AN-101 and PL-AN-111, respectively. Alloy A is hypo-eutectic with a gamma Fe + carbide M7C3 eutectic and austenite matrix. Alloy B is hyper-eutectic comprising coarse columnar M7C3 carbide, graphite flakes and an inhomogeneous austenitic matrix. It was found that alloy A presented a lower erosion rate of 18-41% at 500 degrees C due to the energy-consuming mechanisms of erosion (ploughing and poly-deformation). Alloy B was eroded by a low-cycle mechanism of carbide cracking/chipping. By increasing the testing temperature to 800 degrees C, the erosion rate of the alloys increased by 4.2-6.7 times. The erosion mechanism of the alloys at 800 degrees C was the formation and abrupt spatting of a depressed defective subsurface layer consisting of carbide fragments. Alloy A performed with a lower erosion rate of 39-44% at 800 degrees C due to a lower thickness of the defective layer. Oxidation had a negligible effect on the erosion rate of any of the alloys. The erosion rate of the coatings decreased with the distance from the coating top due to refinement of the carbide M7C3 and graphite inclusions.