In order to ascertain the radioactive geochemical characteristics and lithospheric thermal structure of the Xiangcaoping pluton. Radioelement content

rock density and rock thermal conductivity have been carried for rocks from surface and drilling holes within Xiangcaoping pluton

Northern Gxuangxi. The results suggest that the average radiogenic heat production of investigated granites is 6.00 μW/m

3

obviously higher than those of several other plutons in South China and crustal average. The weighted mean value of rock density is ca. 2.57 g/cm

3

in go

od agreement with the value of global granite. What’s more

the main heat production is sourced from the decay of U and Th

the production from U is higher. The average rock thermal conductivity is 3.174 W/（m·K）

approaching that of the middle-upper crustal rocks. Our new data

together with previous research results

indicate that crust to the surface heat flow more heat flow than mantle contributes

i.e.

Q

c

/Q

m

>1. The contribution rate of Qmto the surface heat flow value is 26%～37%. Douzhashan pluton is typical region with cold crust and heat mantle type lithospheric thermal regime.