Fig. 6.77. Cartoon illustrating the formation of "sedex" (sedimentary-exhalative) massive sulfide ore bodies.
The regional setting is a mid-oceanic ridge, with crustal thinning, rifting, and high heat flow. Metal-enriched
brines emerge from vents along fault-planes forming "smokers." Metallic-sulfide precipitation occurs in the
adjacent brine pools entrapped in the rollover hollow on the downthrown side of the fault. For modern and
ancient analogs see text. (Distilled from Andrews et aL, 1986.)
Fig. 6.78. Manganese nodules on the floor of the Indian Ocean. Individual nodules are about 8 cm in diameter. (From Cronan, 1980, Fig. 88. Courtesy of Academic Press.)
The regional setting is a mid-oceanic ridge, with crustal thinning, rifting, and high heat flow. Metal-enriched
brines emerge from vents along fault-planes forming "smokers." Metallic-sulfide precipitation occurs in the
adjacent brine pools entrapped in the rollover hollow on the downthrown side of the fault. For modern and
ancient analogs see text. (Distilled from Andrews et aL, 1986.)
Fig. 6.78. Manganese nodules on the floor of the Indian Ocean. Individual nodules are about 8 cm in diameter. (From Cronan, 1980, Fig. 88. Courtesy of Academic Press.)