The first drilling of the Messinian salt at the deeper parts of the Mediterranean Sea came in the summer of 1970, when geologists aboard the "Glomar Challenger" brought up drill cores containing arroyo gravels and red and green floodplain silts; and gypsum, anhydrite, rock salt, and various other evaporite minerals that often form from drying of brine or seawater, including in a few places potash, left where the last bitter, mineral-rich waters dried up. One drill core contained a wind-blown cross-bedded deposit of deep-sea foraminiferal ooze that had dried into dust and been blown about on the hot dry abyssal plain by sandstorms, mixed with quartz sand blown in from nearby continents, and ended up in a brine lake interbedded between two layers of halite. These layers alternated with layers containing marine fossils, indicating a succession of drying and flooding periods.