248 Subsurface Geologic Methods 



of differential-heat conductivity into the clay specimen. The rate of heat 

 absorption then continues to decrease more rapidly than the inflow of heat 

 from the block. At this point d between h and c, the reaction ceases. How- 

 ever, since this point cannot be established exactly, a and c are usually 

 chosen as limits. 



Under static conditions the heat effect would cause a rise in temper- 

 ature AT^s of a specimen given by: 



where M= the mass of the reactive mineral, 

 H = xhe specific heat reaction, 

 Mo — the total mass of the specimen, and 

 C = the mean specific heat of the specimen. 

 However, the heat flow from the nickel block towards the centers of the 

 two sample cavities must be taken into account. 



For any point between a and c, the simplified equation describing the 

 changes in heat content of the thermally active constituent is: 



Mj^^Jf+gA;J {T-T)dt=MoC{T-Ta) (2) 



(A) (B) (C) 



for the inert sample: 



8-Ti' r{T,-r)di=Mo'C{r-T,n 



J a 



(B)' (C)' 



(3) 



where t = time. 



Mo = the total mass of the test specimen, 

 Mo = the total mass of the alundum, 



C'= the mean specific heat of the test specimen, 



C'= the mean specific heat of the alundum, 



k = the conductivity of the specimen, 



k'= the conductivity of the alundum, 



g = the geometric-shape constant. 

 To = the temperature of the nickel block, 

 Ta = the temperature at the center of the sample at time 



T = a, 

 Ta — the temperature at the center of the alundum at time. 

 T = a, 



T = the temperature at the center of the sample, 



T'= the temperature at the center of the alundum. 



