Data is a collection of Tiff files of the different series bundled into zip files.Eight new detections of plagioclase-like signatures are reported in their original geologic context in the walls of Valles Marineris.
At one location, the feldspar signatures are clearly associated with a 200 m thick sub-horizontal layer, hinting at an eruptive origin.
DTM and image were calculated using the NASA Ames Stereopipeline.Detection of plagioclase feldspar minerals from remote sensing instruments onboard Mars missions is difficult, and only a handful of occurrences have been reported so far. We present here new detections of such minerals in the giant martian canyon of Valles Marineris, exposed in their original context, and associated at least in one location, to a 200 m thick sub-horizontal layer within the walls. Analyses were performed using visible near-infrared spectral data, which are commonly compared to reference spectra of known terrestrial minerals, or mineral powders, acquired in the laboratory. Whereas previous detections were interpreted as evidence for plagioclase-dominated, or at least, nearly mafic-free, plutonic rocks, we argue here that the Valles Marineris outcrops correspond to erupted, volcanic products. The signature of plagioclase could originate from large crystals hosted in mafic, intermediate, or felsic volcanic rocks; from a lava flow, or from welded ashes. Our new observations confirm that plagioclase detections on Mars can correspond to multiple types of rocks and bring more clues to ongoing debates regarding the extent of Mars' magmatic processes and the nature of its crust.We are grateful to the Mars Reconnaissance Orbiter team for the availability of the data. This study was supported by the CNRS Momentum, LUE future leader programs, and the French “Program National de Planétologie”. The authors acknowledge the support of the French Agence Nationale de la Recherche (ANR), under grant ANR-21-CE49-0003 (MARS-Spec). CRISM data have been processed with the MarsSI (marssi.univ-lyon1.fr) application founded by the European Union’s Seventh Framework Program (FP7/2007-2013) (ERC Grant Agreement No. 280168). The component of the work by Frank Fueten was funded by an NSERC discovery grant
