A Model for Chemical Exchange in the Basalt–Seawater System of Oceanic Layer II

In this paper evidence is presented in support of the hypothesis that the upper 2-3 km of oceanic layer II is a zone of chemical reaction between seawater and the oceanic crust as it moves away from the mid-ocean ridges.A model is constructed assuming that the principal alteration products resulting from the action of sea-water on primary basalts are:1. K-rich smectite formed during weathering of basalt,2. chlorite formed during retrograde metamorphism, and3. albite–actinolite formed during primary greenschist metamorphisms at the ridge crest.These three processes in combination could extract most of the stream input of K+, Mg2+, and Na+ and add SiO2, Ca2+, Fe2+, and Mn2+ to the ocean systems in amounts comparable to stream input.The steady state reaction of basalt with interstitial seawater to produce alteration minerals could exercise a strong influence in the chemistry of seawater and release energy in amounts sufficient to form a portion of normal heat flow measured on the ocean floor.