½éÉÜ£º The thermo£¬electric coefficients oftwenty¡ªsix magnetite samples£¬formed either by magmatism or metamorphism£®were tested by the thermo¡ªelectric instrument BHET-06£®Results showed that the coefficientiSofaconstantvalueofabout C£®ItiSemphasizedthatbecause everymagnetitegrainwas tested randomly£®the coem cient iS independent ofthe crystallographic direction£®This faCt means the therma1 voltage generated from a single magnetite crystal can be accumulated£¬and as a result a new thermo-electric field can arise when a gradient thermal field exists and iS active within the earth¡¯S crust£®Because magnetite iS widespread in the earth¡¯S crust fgenerally appearing more in the middle¡ªlower crust)£¬there iS more¡ªthan¡ªrandom probability that the additional thermo£®electric field can be generated when certain thermal condi¡ª tions are fulfilled.....