Compositional stratigraphy, consisting of Al-rich kaolinite overlying Fe/Mg-richnontronite, is sporadically distributed within 40{degree sign}S to 30{degree sign}N on Mars. The compositional stratigraphy was considered a typical product of a warm and wet climate, and a window into understanding the atmospheric conditions of early Mars. However, the question remains as to whether the compositional stratigraphy was formed by chemical weathering or sedimentation. Variations in mineralogical/ geochemical properties along the compositional stratigraphy can provide important clues for interpreting the genesis of the compositional stratigraphy. Visible to near infrared (VNIR) reflectance spectroscopy has been used as an effective tool to quantitatively characterize the abundance of kaolinite, nontronite, and weathering intensity in a basaltic weathering succession, as demonstrated by a terrestrial regolith profile. Nevertheless, the VNIR spectra could be influenced by primary minerals and organics in a basalt succession. To test the effectiveness of spectral parameters, the stepwise transformation of nontronite to kaolinite was experimentally modeled and quantitatively investigated using thermogravimetric (TG) and VNIR. The correlation between BD1400 and the content of OH, BD1900 and the H₂O content, and BD1400/BD1900 and the OH/H₂O ratio were quantitatively constrained to demonstrate their effectiveness as spectral proxies. The obtained data set was also compared with the VNIR spectra from the compositional stratigraphy on Mars, and the continuous variations of the spectral proxies suggest the compositional stratigraphy is formed by a surface chemical weathering process. Accordingly, Mars likely had a warm and wet climate that could maintain liquid water on its surface over a geologic time span.