A concise survey of the occurrence and varying formation environments of feldspathic rocks in the southern highlands, Mars

Abstract

Presented here, is a synthesis of previous studies that have resulted in the discovery of feldspathic material on the Martian surface through the utilization of orbital (e.g., OMEGA on Mars Express and CRISM on MRO) and ground based (e.g., ChemCam aboard Curiosity) data sets. Also, presented here for the first time, are additional CRISM detections of feldspar-rich material concentrated in a portion of the southern highlands region of Mars comprised of Noachis Terra, Tyrrhena Terra, and Terra Cimmeria. Possible mechanisms of formation and geochemical formation environments are proposed for the newly observed occurrences based on the localities, and proposed formation mechanisms and environments, of confirmed detections addressed in previous studies. The sites that will be analyzed in depth consist of (1) three infilled, flat-floored impact craters in Noachis, Tyrrhena, and Cimmeria that contain feldspar-rich material within their exposed stratigraphic layers, which is observable in a terraced outcrop, a fractured, light-toned outcrop (igneous or sedimentary in origin), and ejecta surrounding impact craters that sampled the infilling material and (2) a complex crater in Cimmeria with brecciated blocks of feldspar-rich material scattered about its central peak. The IR spectral properties of feldspar, as well as other mineral phases that were found in association with it, are discussed in order to comprehend the conclusions made from the presented remotely sensed data (i.e., CRISM ratioed I/F). The methods employed for CRISM data selection and processing are also emphasized with the resulting data products being introduced and differentiated between.