or not Point to Ancient Acid Ocean
and as any chemist will tell you basalt dust plus an ocean of acid equals reaction products plus water until either basalt or acid is consumed. Since basalt is still there , then the acid must have been consumed. But then you don't have the conditions for jarosite (acid plus oxidizing). So back in the acid-fog corner we have "Acid-fog deposition at Kilauea volcano: A possible mechanism for the formation of siliceous-sulfate rock coatings on Mars" by Schiffman et al. in the same issue of Geology.