The lead and strontium isotope geochemistry of metalliferous sediments associated with Upper Cretaceous ophiolitic rocks in Cyprus, Syria, and the Sultanate of Oman: Reply

Metalliferous sediments consisting dominantly of fine-grained iron and manganese oxides and hydroxyoxides have been widely recorded from the crests of sea-floor spreading ridges and as a basal facies of the sediment accumulations of the oceanic crust. Similar sedimentary rocks that, in Cyprus, for example, contain 10–44 wt.% Fe and 2–16 wt.% Mn, occur in association with ophiolitic rocks. These chemical precipitates are thought to have formed by oxidation of hydrothermal fluid released in submarine hot-spring areas in the discharge zones of ocean-floor geothermal systems that contained convectively circulating sea water.Lead isotope ratios of 18 samples associated with Upper Cretaceous ophiolitic rocks of the Troodos massif, Cyprus (6 samples), the Baer-Bassit area, Syria (6), and the Semail nappe in the Sultanate of Oman (6), indicate that the metalliferous sediments contain lead leached from the underlying basaltic oceanic crust during hot water – rock interaction. The amount of basaltic lead varies fro...