GEOCHEMICAL COMPONENTS IN MARTIAN SOIL

Trends in element compositional variation among samples at the Viking lander sites on Mars provided evidence for multiple geochemical compon ents in the soils. A simple two-component model can explain all pair-w ise trends of eight elements analyzed. Component A contains Si and mos t or all the Al, Ca, Ti, and Fe. Component B, which is 16 +/- 3% by we ight of the total, contains S and most or all the Cl and Mg. These res ults constrain several models of Martian soil mineralogy but are consi stent with a mixture of silicates and salts.