Sputter Initiated Resonance Ionization Spectroscopy (SIRIS), based on the concept of laser-induced resonance ionization of sputtered atoms, offers the potential to make in-situ chemical and isotopic microanalyses possible with excellent sensitivity to low concentrations and combined excellent spatial resolution. This project is a Phase I award under the Small Business Innovation Research Program that will test SIRIS methods for analysis of calcium and titanium isotopes in geological samples. The research plan is to assess interference problems from sputtered ions and nonresonant photo-ions and to identify analytical procedures for SIRIS analysis of calcium and titanium. The studies will form a basis for more general development of SIRIS microanalytical techniques for geological samples.