Contribution of Ue3 to geo-neutrino flux

We show that a non-zero Ue3 close to the CHOOZ bound ($Sin^2 2 \theta_{13} \simeq 0.16$ 90% CL) can change the geo-neutrino flux by 12%. Geo-neutrino detection in Kamland with a exposure of $3\times {10}^{32}proton-years$ is sensitive to $Si{n}^{2}2{\theta }_{13}$ to the level of $0.2(1\sigma )$. For the same exposure a detector close to Himalayas can probe $Si{n}^{2}2{\theta }_{13}$ down to $0.15(1\sigma )$ due to higher geo-neutrino flux from the Tibetan plate.