Distinguishing Marine and Freshwater Muds

Abstract

A wide sampling of eighty-two modern marine and freshwater muds was analyzed for B, Cr, Ga, Ni, V, clay in amounts less than $$2 \mu (<2 \mu clay)$$, clay minerals, $$CaCO_{3}$$, and organic carbon. Results show that total B is highly correlated with the amount of $$< 2 \mu$$ clay; for a given clay content, modern marine muds contain about 30-45 ppm more B than modern freshwater muds. Illite has little if any control on B concentration in muds. A discriminant function $$z = 0.00095x_{B} - 0.07910x_{clay}$$ based on B and < $$2 \mu$$ clay was found to be the most practical and effective combination for distinguishing between modern marine and freshwater environments. If a single differentiator is used, B is superior to clay content. The elements Cr, Ga, Ni, and V are not collectively good differentiators; clay minerals, $$CaCO_{3}$$, and organic carbon also fail to distinguish the two environments effectively. Data support the theory of Levinson and Ludwick (1966) that B in modern marine muds increases progressively seaward from a strandline as the amount of total clay increases.