This dissertation contributes to the development of novel non-traditional isotopic systems and their application in understanding the formation histories of various planetary bodies, including Earth. It involves laboratory experiments on evaporation of alkali elements from silicate melts, and the chemical purification and isotopic analysis of titanium (Ti) in Archean mafic and felsic igneous rocks. In Chapter 1, I reviewed the alkali depletions and isotopic variations of K and Rb in different planetary bodies and the mechanism that accounts for their depletions and associated isotopic fractionations. I reviewed the laboratory experiments on evaporation and condensation as it provides better constraints on how these alkalis became depleted. I also reviewed the Ti mass-dependent isotopic fractionation on modern terrestrial rocks, showing that Ti isotopes are fractionated differently in different modern magma series and could provide valuable constraints on the upper continental crust composition in the past. In Chapter 2, I carried out vacuum evaporation experiments to study the Na, K, and Rb evaporation kinetics and K and Rb isotopic fractionations. I found zoning profiles for both elemental and isotopic compositions of K. I developed analytical equations to solve for elemental and isotopic evolution during diffusion-limited evaporation. In Chapter 3, I expanded evaporation experiments to all alkalis (i.e., Li, Na, K, Rb, and Cs) under various conditions by changing temperature, pressure, oxygen fugacity, and melt composition. I integrated the experimental results into a quantitative thermodynamic modeling framework, extracting parameters that were further applied to understand the formation history of asteroid 4 Vesta. In Chapter 4, I carried out the Ti and iron (Fe) isotopic analyses of Archean metabasites and granitoids from different cratons. Archean granitoid provides critical clues on how Earth's felsic crust was established and its geodynamics evolved. I further applied thermodynamic and equilibrium isotopic modeling to understand the genesis of Archean granitoid, encompassing processes such as partial melting of metabasites and secondary melting or crystallization processes in tonalitic crust. This modeling successfully reproduces the observed Fe and Ti isotopic variations in Archean granitoids. The results have defined the Ti isotopic compositions of Archean felsic endmember and suggested a predominantly felsic composition of the post-3.5 Ga Archean crust, thereby reinforcing the conclusions of previous studies.